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Site & Board Matters => About This Site => Topic started by: BJL on September 28, 2005, 07:04:45 pm

Title: the so called minuature formats
Post by: BJL on September 28, 2005, 07:04:45 pm
It is interesting that Michael wraps up his recent essay with a reference to the introduction and eventual dominance of the "so called miniature format", the 24x36mm of 35mm film cameras. Interesting because he otherwise rejects the idea that smaller formats have virtues for professional and enthusiastic amateur photographers. His predictions turn largely on two ideas
a) expectations of the FF price penalty getting below US$1,000
 the claim that cost is the only advantage of a smaller format (as if the downsizing progression from LF to MF to 35mm film format was solely for cost reasons.)

His strange weight comparions of the very robustly built and three year old E-1 to the new unsealed body of the 5D is a bit strange; for a different spin, compare the new lightest Four Thirds body (the new Olympus E-500, at 479g) to the new lightest FF body (the 5D at 895g): about one pound difference.


But the big missing point is lenses, and how they will increase the size and weight of the larger format kit needed to realize most of the claimed advantages, if suitable lenses exist at all.

1) You get absolutely no advantage from a larger sensor unless you also use a longer focal length, to spread the image over more sensor area. Using the same focal length as with a smaller sensor and then cropping more means that you use only a portion of the larger sensor of the same size as the smaller sensor. (Meanwhile you have to compose for a heavy crop in the viewfinder.)

2) Using a longer focal length but the same effective aperture diameter (f-stop increased in proportion to focal length) helps only with image quality at close to minimum ISO speed, requiring a lower shutter speed than with the smaller format due to the higher f-stop. When instead the larger format uses ISO speed a stop or more above minimum, the smaller format with its lower f-stop can use a lower ISO and yet the same shutter speed, and this lower ISO balances out the noise/DR advantages of the larger sensor when sensors are compared at equal ISO.


3) That leaves only using larger focal lengths and larger aperture diameters: for example, using equal f-stop despite the longer focal length. This only applies when the larger format can use a larger aperture diameter than the fastest lens available for the smaller format at the equivalent focal length, because if the smaller format can match aperture diameter, we are back in case (2).

Simple optics and physics says that this high speed advantage requires bigger front elements and lenses that are heavier and probably more expensive, and also leads to very shallow DOF (often a disadvantage, believe ot or not!)

What will sports/action/wildlife users choose? Probably telephotos are the main realm where high speed is of great importance, and beyond about 85mm for primes and 200mm for any lenses for 35mm format, the speed advantage only exists for only a very few heavy, expensive lenses, like a 400/2.8. Shorter but brighter telephoto lenses for use wit hteh smaller formats, like the new Nikon 200mm f/2, can probably eliminate most or all of this high speed/low light/low DOF performance difference. As to price and weight, comparing that Nikon 200/2 to a 300/2.8, or a 400/2.8 to a 600/4 suggests that there is no significant price or weight penalty to this "shorter but brighter" telephoto lens strategy,and in fact probably  abit of a size and weight advantage. Any performance difference that remains will continue to cost and weigh a lot.

Only wide to short telephoto focal lengths have a likely long-term advantage from larger apertures in 35m format; a realm where I expect most photographers will find few problems with the speed of the smaller DSLR formats.



To me, case (2) always has been and probably always will be the main larger format advantage: more dynamic range, finer tonal gradations, and maybe more resolution, by using low ISO for optimal quality and generally higher f-stops and lower shutter speeds than with smaller formats.


P. S. I do not see the existing lens pool holding back smaler DSLR formats much. For focal lengths beyond about 60mm, 35mm format lenses work equally well (though differently) with smaller formats, since such lens designs naturally throw an image circle big enough for the 35mm frame size. So the transition to smaller formats does not obsolete many lenses. It typically require getting one or two new shorter ones, and in exchange, the longest one or two lenses might become dispensable.

Anyway, a majority of DSLR buyers have never previously owned a 35mm format SLR, and so have no legacy lenses.
Title: the so called minuature formats
Post by: John Camp on September 28, 2005, 08:13:23 pm
I've noticed on a number of forums that people are using the phrase "legacy formats," and to me that signals a critical shift in thinking (if that shift might also reflect on the way camera manufacturers may be thinking.) I see little advantage to "full-frame" sensors, and quite a few for the smaller sensors. (I will grant that there are some definite advantages to legacy size cameras for people who need to strongly manipulate depth of field; but this will eventually be rendered less important by Photoshop.) It would be a curious reversal if Canon someday found itself to be the "new medium format" camera: much more expensive both as a camera body and a system, and carrying much more weight, and often relegated to specialist photo applications -- fashion and landscape -- while cameras with non-legacy sensors (perhaps not only APS-C, but possibly even with a 6x7 or 5x4 ratios) become the "new 35s" used for all photo journalism/action/street shooting, and even fashion and landscape where huge print sizes are not required. The Sony P&S zoom cameras will never have the flexibility of a fully exhangeable-lens system, attractive as they may be -- and if they were smaller, I would find them very attractive indeed. They will eventually wind up like the film point-and-shoots; there were, in that category, some extremely able cameras, if you can remember back that far...

I will have to say that I've always found Michael Reichmann's specific loyalty to the legacy-sized sensors to be odd, given that much of his most critical shooting is with a different format (and he's always seemed fair-minded enough that I would NOT attribute this to any connection with Canon.) Well, I suspect we will see, and really, rather quickly. By 2008, who knows...?

JC
Title: the so called minuature formats
Post by: Ray on September 28, 2005, 11:40:24 pm
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But the big missing point is lenses, and how they will increase the size and weight of the larger format kit needed to realize most of the claimed advantages, if suitable lenses exist at all.

BJL,
Look! The bottom line is this. The smaller format will always have the advantage of being lighter, but always at the cost of a sacrifice in image quality. If someone can design a smaller format that is significantly lighter than a larger, heavier format but offers equal (or close to equal) image quality at a similar price, then such a camera will have a huge competitive advantage in the market.

The D2X almost fell into that category. Image quality is almost on a par with the heavier 1Ds2 and the savings in weight (as well as price) can justify, for many, that slight loss in image quality and increased noise at high ISOs. That's fine. I'm all in favour of the consumer having a choice, but ultimately, with equal technological development amongst formats, comparing the latest with the latest, the larger format will always retain an inherent image quality advantage.

The issue therefore revolves around the size of the various trade-offs. Is the weight advantage significant but the image quality loss only marginal, or vice versa?

It seems to me, the Olympus 4/3rds format is really a competitor to the APS-C format. Affordable FF 35mm could well knock it out of the market, as Michael predicts.

You argument that lenses longer than 60mm have a sufficiently large image circle for a larger format, even though they might have been designed for a smaller format, is working against your main premise here. Again you are shooting yourself in the foot.

To make this clear, I'll give a concrete example. Let's say I'm mainly interesting in shooting wildlife and sporting events where the smaller format such as the 4/3rds and APS-C supposedly have an advantage. I consider 300mm to be my most used focal length and I look around for systems that support an excellent 300mm lens.

I'm impressed with the Zuiko 300/2.8 for the 4/3rds system, but I'm concerned that the FoV might be too narrow (effectively that of a 600mm lens on FF 35mm), however a 300mm lens is a 300mm lens. The size of the sensor cannot change that fact.

I consider the Canon 300/2.8, also a very fine lens, up there with the best that Canon produce, if not the best. I'm torn between the Canon 1Ds2 with 300/2.8 prime lens, and the latest 8 megapixel Olympus 4/3rds with Zuiko 300/2.8 lens.

I compare the specs. What do I find? Lo and behold, the Zuiko 300/2.8 is actually heavier than the Canon 300/2.8; 3.3KG as opposed to 2.55KG for the Canon. I don't know what the street prices for these 2 lenses are, but the RRP prices are about the same, with the Canon perhaps being marginally cheaper.

Now I'm not going to quibble about a few grams. A 1Ds2 plus 300/2.8 lens is going to be insignificantly heavier or lighter than an Olympus/Zuiko 300/2.8 combination and therefore not a factor in my deliberations.

The point has been made many times in this forum; it makes no difference if the camera's sensor does the cropping or the image editing program. Cropping is cropping.

The difference between these two systems is one of cropping choice. With the olympus/Zuiko 4/3rds system, I've got less choice. The sensor crops the image circle to a far greater degree than does the FF Canon/300mm combination. I would therefore much prefer to use the 1Ds2/300mm combination, unless, of course, the cropped 1Ds2 image is inferior to the Olympus 4/3rds image  ??? .

And here's the rub. I haven't seen any direct comparisons, but I'd be prepared to accept that currently the 8mp Olympus image would be sharper and more detailed than the cropped 4mp 1Ds2 image. If this wasn't the case, there'd really be no reason for the 4/3rds system to exist.

However, this latest article of Michael's is addressing trends and future scenarios. The current advantage of the 4/3rds format in my example above is partially offset by the choice of a wider FoV with the FF format, with any lens. Furthermore, the resolution advantage of the 4/3rds format will continue to be eroded as it becomes economically viable to produce FF sensors with higher pixel densities.
Title: the so called minuature formats
Post by: Willowroot on September 29, 2005, 10:21:59 am
That makes little sense.  If you wanted a 300mm FOV you'd be looking at a 150mm lens for the Oly, not 300.
Title: the so called minuature formats
Post by: Del on September 29, 2005, 10:46:37 am
I've just come fron handling a new Canon 5D at the camera store where I do business. As a current XPan (film) user, I've just been waiting for the right digital camera.  For me, this is a full frame digital camera and Canon appears to have built this model for people like me. Kudos to Canon for giving so many of us-what we have been waiting for-at a price many of us can live with.  Imagine, giving customers what they desire, and are willing to spend their dollars on-what a concept! This is not a question of legacy to me-I'm just thrilled to have this choice at this price point.  Who wouldn't like it to be less expensive, but that also will follow.
Title: the so called minuature formats
Post by: crspe on September 29, 2005, 01:59:55 pm
I agree with BJL's initial comments on this topic - even given that the price difference between FF and 1.5x sensors drops, that is not necessarily enough to relegate the 1.5x to the low quality consumer market.

I believe that the 1.5x cameras will provide image quality that is good enough!  That is the key word here - I dont need better, I am confident that within a couple of years, we will have an 11Mpixel 1.5x sensor on the market at the same price as todays 20D/350D, with the same or lower noise.  That is what these cameras gave us over their predecessors - 33% more pixels at the same price and the same noise.
At 11Mpix and the noise of the 20D, I dont need anything else, but I have these advantages over a FF set-up:
  You can cover the same zoom range with cheaper, smaller, lighter lenses - I own a 10-22, 17-85, 28-135 and 100-400. To cover the same range on a FF camera (effective 16mm to 560mm), would cost and weigh lots more.
  The camera is also smaller, cheaper, lighter

I believe that within a few years, people who used to shoot medium format will move to FF (these are the people who really need extreme quality).  People who used to shoot FF will move to 1.5x sensors - Its good enough, and to get better is just not worth the extra cost and weight.
Title: the so called minuature formats
Post by: BobMcCarthy on September 29, 2005, 03:05:13 pm
I have never thought of Michael as being dishonest in any of his analysis. I do feel he assigns a bit of "hero" status to some of his interview subjects. Adobe (Knoll), Phase (Raber?), and Canon (?)has been pulling at his heart strings. He appears to give them the benefit of doubt in any issues regarding them.

I have always approached the subject of FF vs DX as an economic issue. I have no doubt that technology will advance in many ways (hardware and software)where we reach a point of "good enough and then some" with reduced format sensors. It appears the huge installed base of 35mm lenses are a powerful reason for the infrastructure to leverage off of that base.

DX is very good already and will likely continue to get better. The edge to edge sharpness issue is probably the FF archiles heel. I can even see a small amount of differential in the DX world. It approaches unacceptable with FF.

All the above can be solved as new FF lenses, sharp edge to edge, are possibly introduced. Far more important with wide so the entire line doesn't need to be revamped. These babys will cost a pretty penny though.

All this has been discussed endlessly. BJL has provided valuable insight into the optical side. Others have contributed on other issues.

But, in the final analysis, it comes down to money. Sure FF will come down somewhat in cost, but DX/AP-C will always be less expensive and deliver acceptable quality at a lower price to the customer. Technology only makes it better. I can see the day of a 12-15 mpxl camera going for $500 in basic trim and it will be DX long before its FF. The market will flatten when that occurs as high quality becomes universal and improvements will be based on other issues like in the old days.

Maybe Nikon will produce a FF camera but it will be to compete with Canon for the Medium format customer. That customer base can grow well beyond the 'blad days as it shares infrastructure with 35mm systems

Medium format is becoming marginalized and less and less economic. 35FF digital will replace it. I suppose med format can replace large format, but the cost differental is enormous. Large format film is cheaper than 35mm/DX digital at the pro level, just not as versatile. When med format digital unit volume drops below a certain level it will implode in on itself. Just not enough units to fund R&D etc. In the meantime 35mm based digital camera are closing in.

In the end its all about economics, no matter what our heart tells us.

bob
Title: the so called minuature formats
Post by: Ronny Nilsen on September 29, 2005, 03:53:23 pm
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In the end its all about economics, no matter what our heart tells us.

It's also about physics. With todays senors we are aproching the diffraction limit, and if you want more pixels you will have to have a larger senors.

So even if we some day in the future can make senors with no noise in any size we wish, the diffraction limit will set a barrier and make it meaningless to make them smaller.

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You can cover the same zoom range with cheaper, smaller, lighter lenses - I own a 10-22, 17-85, 28-135 and 100-400. To cover the same range on a FF camera (effective 16mm to 560mm), would cost and weigh lots more.

In a FF camera with the same pixel density as the smaller sensor, you could cover the same range with 16-400mm lenses and get the same or better image quality. You would only need a 560mm if you want beter quality than the smaller senor can give you. A 400mm on a FF will give the same image after cropping i PS as the smaller sensor. :cool:
Title: the so called minuature formats
Post by: Ben Rubinstein on September 29, 2005, 04:07:30 pm
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What will sports/action/wildlife users choose?

As you say, for most everyone else, especially those who don't have huge studios and want to keep their legacy lenses for the purpose that they were bought or don't want to buy a new bunch on DX/AFS lenses - Crop sensors are a serious pain in the tuchus and to heck with them.

If I was going on safari then I would take a 20D no question, for a wedding or portrait session you just try and tear that FF DSLR away from me!
Title: the so called minuature formats
Post by: BobMcCarthy on September 29, 2005, 04:35:35 pm
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In the end its all about economics, no matter what our heart tells us.

It's also about physics. With todays senors we are aproching the diffraction limit, and if you want more pixels you will have to have a larger senors.

So even if we some day in the future can make senors with no noise in any size we wish, the diffraction limit will set a barrier and make it meaningless to make them smaller.


At what point is enough, enough?

At 300 dpi, just how big are you going to print. I'll admit my average print has moved up to 13x19 and 18x24 compared to 8x10 and 11-14 in the film days but...

Hardly worth playing with 30-40 meg files, that turn into monster Tiffs, especially with the way some folks just hammer on the shutter release. The amount of processing is out of control. Some digital trained folks shoot more in a month that I did in a decade in the film days. I already spend too much time in processing...

I disagree that DX/APC sensors are approaching the limits...

Maybe some of the P&S but not DX. You're being too theoretical.

Bob
Title: the so called minuature formats
Post by: Ray on September 29, 2005, 06:55:46 pm
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That makes little sense. If you wanted a 300mm FOV you'd be looking at a 150mm lens for the Oly, not 300.
The point I'm trying to get across is one that's been misunderstood from the day the first APS-C DSLR hit the market, and it's this. A 150mm lens or a 300mm lens is just that, whatever camera it's attached to. I can never get a field of view greater than the inherent image circle thrown by the lens, whatever the focal length of the lens, but I can reduce the FoV as much as I want by cropping.

Whilst it's true that a 150mm lens on a 4/3rds format produces the same FoV as a 300mm lens on a FF frame 35mm camera without more cropping than has already taken place in-camera, there's nothing to stop me continuing to crop the image in Photoshop. The more I crop, the narrower the FoV becomes. Why stop at the degree of cropping already done by the camera's sensor? Answer: because the more you crop, the lower the image quality.

A cropped image from a 150mm lens ultimately can never have the same quality as an uncropped image from a 300mm lens, if both lenses are of similar quality. As sensors continue to have greater pixel density to a point beyond the resolving capacity of the lenses used, and as the prices of FF 35mm sensors fall, the APS-C camera becomes a less attractive proposition.
Title: the so called minuature formats
Post by: Ronny Nilsen on September 29, 2005, 07:10:05 pm
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I disagree that DX/APC sensors are approaching the limits...

Maybe some of the P&S but not DX. You're being too theoretical.

It depends on subjective factors ofcourse, but for me my 20D has small enough pixels. If I stop down to f/22 or smaller the effect is visible.

Take a look at  http://www.cambridgeincolour.com/tutorials/diffraction-photography.htm to see a visualisation of the size of the airy disk.
Title: the so called minuature formats
Post by: BJL on September 29, 2005, 08:39:18 pm
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It's also about physics. With todays senors we are aproching the diffraction limit, and if you want more pixels you will have to have a larger senors.
If diffraction got to be a problem at even the largest apertures of lenses (as it possibly is with 8MP 1/1.8" sensors), then there would be a problem. DSLR's are not even close: the D2X is diffraction limited only at about f/11 and beyond.

That leaves diffraction problems only when one stops down to get lots of DOF. Changing to a larger format requires using a higher f-stop to achieve that same DOF, making the diffraction effect equally great.

That is, once again, comparing different formats at equal effective aperture diameter (focal length divided by f-stop) gives equal DOF and equal diffraction effects on equal sized prints; no advantage to either larger or smaller formats.

One difference is that since the larger format is then using a higher f-stop, it must use either a higher ISO speed or a lower shutter speed, vaporising its supposed noise/speed advantage.
Title: the so called minuature formats
Post by: BJL on September 29, 2005, 09:02:59 pm
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The bottom line is this. The smaller format will always have the advantage of being lighter, but always at the cost of a sacrifice in image quality.
Exactly: lighter, cheaper, and in some situations less image quality, but in others, no noticable difference.

This is the same trade off that 35mm film offered in comparison to the earlier larger roll film formats, and 4"x5" sheet film in comparison to the older, larger 5"x7" and 8"x10" sheet film formats. In each case, smaler not only survied but evedntualy dominated ove teh older, bigger formats. So clearly the advangtages of small can be sufficient for healthy survival sometimes, contradicting the simplistic "bigger formats give better image quality and so will eventually dominate" argument.

Please explain why 35mm (and 4"x5") did so well despite their "size disadvantage".


Your comparison of Four Thirds and 35mm both with 300/2.8 lenses shows that you have totally missed or ignored one of my main points: a larger format needs to use longer focal lengths, or the extra sensor area is completely wasted.

Another point about cropping and focal length needs: the Canon 35mm format DSLRs have all consistently had distinctly lower sensor resolution (wider pixel spacing) than contemporary far less expensive smaller format DSLRs. For that reason also, they must use longer focal lengths to record about the same amount of detail from a subject.

And why compare to Four Thirds in particular? I used Nikon DX for my main examples, since that is clearly the current pre-eminent "smaller than 35mm" DSLR format. Nikon DX is above all the one that the one that Canon's 35mm format has to vanquish in order to fullfill your apparent desire that photographic enthusiasts be denied DSLR options that are smaller, lighter and less expensive than 35mm format, while also clearly exceeding 35mm film quality overall, as the D2X already does.
Title: the so called minuature formats
Post by: John Camp on September 30, 2005, 12:11:58 am
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A cropped image from a 150mm lens ultimately can never have the same quality as an uncropped image from a 300mm lens, if both lenses are of similar quality.
Quote

I either don't understand this, or don't understand your argument, one or the other. I'm willing to take a further explanation of either.

An APS-C image is NOT cropped. It's the full size of the APS-C. It simply uses less of the lens' circle. So what? The FOV in an APS-C at 200 is the same as in a FF at 300. So what?

The APS-C isn't cropped, nor is it the same thing as a crop, because -- and this is the crux of the question, or the problem -- the sensors are not the same. All of the D2x's pixels are in the APS-C sized sensor; most of the Canon's are outside of that similar area on the Canon's sensor. So a D2X has much more resolution and sharpness over the APS-sized area, does it not?

I really don't understand this focus on "crops," or even what is meant by that. A crop is when you have an image and cut the edges off of it, either on paper or in Photoshop. You simply throw away pixels; the pixel density doesn't change. If the pixel density across a ff sensor were the same as across an APS-C, *then* the APS-C with the same FOV would be the equivalent of a crop.

But they're not the same. Anmd most reviewers would suggest that the quality of a 200 D2x and a 300 1DsII are extremely close -- so close that something other than resolution or sharpness might very well be the deciding factor of which you buy. If you want fast long lenses, lighter weight, less cost (and, for the time being, anyway, better corner sharpness in wide angle lenses) then you go with the D2x. If you want more easily manipulated depth of field, better high-ASA performance, or (according to some reviewers) slightly greater DR, then you might want to go with the 1DsII.

But crop? Not a factor.

JC
Title: the so called minuature formats
Post by: Ronny Nilsen on September 30, 2005, 02:39:08 am
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It's also about physics. With todays senors we are aproching the diffraction limit, and if you want more pixels you will have to have a larger senors.
If diffraction got to be a problem at even the largest apertures of lenses (as it possibly is with 8MP 1/1.8" sensors), then there would be a problem. DSLR's are not even close: the D2X is diffraction limited only at about f/11 and beyond.

That leaves diffraction problems only when one stops down to get lots of DOF. Changing to a larger format requires using a higher f-stop to achieve that same DOF, making the diffraction effect equally great.
There is another reasons for wanting to stop down, and that is to control shutter speed.   ::

So for me (not you or anybody else) I feel that I am aproching (not passing or indicating that it's problem on current DSLR's) the diffraction limit. I am not thinking of a particular camera here, we are talking about cameras in the future and the direction we are headed in.

It's not unlikely that we in, let's say 5 years, have cameras with different size sensors but with about the same pixel size that is close to diffraction limit of say f/5.6.

Then you can chose your image resolution based on sensor size the same way we have up to now done so by choosing different film formats.

And if you have been unlucky and bought a FF camera and want the benefits a redused sensors gives to your images, you can always put som duck tape covering part of your sensors and focusing screen to get the improved image quality.  :D

The paragraph above is ment as humor, but it illustrates that in the long run image quality is tied to sensor size the same way it has been with film. But for most people a redused size sensor will give more quality than they need (and probably does already).
Title: the so called minuature formats
Post by: dturina on September 30, 2005, 03:17:48 am
What I did mind in this whole thing, at least watching the Olympus SLR forum on dpreview, is that Michael was again unfairly attacked, as if he insulted a leader of some cult, and now the followers are out for revenge. The similar thing happened to Mike Johnston, and now he stopped writing his columns, which is a great loss for the photographic community. People take cameras way too seriously, it seems.
I, personally, can't tell if it's better to invest in full frame 35mm sensor and lenses, or in 4/3 sensor and lenses. It probably depends on what one finds to be good enough. A couple of years ago Michael said that 3MP Canon D30 equals 35mm film, and that 6MP D60 is actually better than 35mm film. OK. So let's see, Olympus makes an E1 body with 5MP (which I own, BTW), and this body is generally agreed to have picture quality similar to Canon 10D, which should be better than 35mm film. In reality, when I compare A3 prints between E1 and my Minolta film gear, film has less clarity, and the amount of detail is either similar, or E1 is better. That goes hand in hand with Michael's estimate. So what do I have here? I replaced my film gear with equally powerful digital gear, and saved lots of money and time on processing and scanning. Why would I complain about limitations of the 4/3 format? That would be the case only if 135 film wasn't enough, and I wanted to upgrade to medium format.
Technically, Michael is right - bigger sensor will give you better quality of information per pixel, all other things being equal. However, are they? I mean, Canon FF cameras are obviously lens limited. Only the best lenses give optimal results, and that usually means L primes. So if you want to extract all that extra resolution the sensor allows, you have to shoot with primes, like with medium format. Fine, but that is not very convenient. On the other hand, Olympus makes great 4/3 zooms, with excellent resolution. 4/3 is sensor limited, while 35mm is glass limited. Sure, I guess when Canon makes a 24MP 35mm sensor, Olympus will have to stop at 12 - what a major tragedy that would be. However, let say, for argument's sake, that Olympus releases a 12MP sensor camera with resolution and DR better or equal to Nikon D2X. Would anyone have reason to complain about limitations of reduced format? I don't think so, as 12MP Nikon equals 6x6 Velvia scan, from what I've seen. The only way up is through medium format backs, not small format cameras. Michael himself has two systems - Canon and Contax. What's the problem if someone builds one system around 4/3, and another around a 35mm or even a 645 sensor? Why would 4/3 be limiting, if it allows me to pack 28-400mm range in two reasonably compact lenses, and get quality similar or identical to that of Canon L glass and a 10d body? I am very pleased with the results I produce with my E1. Yes, I can hardly wait for them to release a professional grade body with better resolution and noise performance. However, I'm not getting into seizures over it all. I use what I have, and try to improve my photography, as I did with 35mm film. I'm not into insane consumerism. If a 3 MP camera equalled 135 film three years ago, then I guess it still does today. So why would I treat a great 5MP camera as obsolete and outdated, when it actually still does outresolve 35mm film, still makes great pictures, and there always were better, bigger format cameras around? Well, just my two cents, anyway.
Title: the so called minuature formats
Post by: Ben Rubinstein on September 30, 2005, 06:58:48 am
Attacking Michael seems to be the national sport on forums after his essays, as if somehow he isn't entitled to his own opinion. MR must have thick skin or more rightly just not care about what people say and say and say..........while he's in an exotic location like China taking photos with the new equipment. I know which side of the ring I'd prefer to be in!  
Title: the so called minuature formats
Post by: dturina on September 30, 2005, 07:43:10 am
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Attacking Michael seems to be the national sport on forums after his essays, as if somehow he isn't entitled to his own opinion. MR must have thick skin or more rightly just not care about what people say and say and say..........while he's in an exotic location like China taking photos with the new equipment. I know which side of the ring I'd prefer to be in!  
I know what you mean, and I know Michael says he has thick skin, but I do feel that unfair criticism really hurts him, which is quite normal. Actually, I would doubt his sanity if he were indifferent to it all, as it is not just criticism, but consists of very malicious personal attacks and slander, most of which would be prosecuted in courts, if Internet weren't such a mess. I stopped writing on dpreview forums because Phil Askey ignored my complaints about venomous personal slander by a user. I just didn't want to be a part of a place maintained by a man who de facto supports such behavior and earns sponsorship money from all the slander generated traffic.

The second part that irritates me are attacks on MR's photography - always and without exception by those who either produce or consume kitsch and cat/dog/child snapshots. I guess photography is subjective, and this leaves room to all kinds of idiotic opinions, but the problem with those people is that they have such immature and primitive taste, that they cannot discern between photography that looks good on 700x500 px resolutions on screen, and stuff that is printed big and hung on a wall, to complement the room atmosphere. I know what kind of stuff they'd call "good" - extreme kitsch, with simplified composition and maxed colors. Well I invite them to hang this stuff in their place, and make it look like Gipsy circus. Whew, I feel better already.
Title: the so called minuature formats
Post by: Ray on September 30, 2005, 07:47:19 am
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A cropped image from a 150mm lens ultimately can never have the same quality as an uncropped image from a 300mm lens, if both lenses are of similar quality.


I either don't understand this, or don't understand your argument, one or the other. I'm willing to take a further explanation of either.

An APS-C image is NOT cropped. It's the full size of the APS-C. It simply uses less of the lens' circle. So what? The FOV in an APS-C at 200 is the same as in a FF at 300. So what?

The APS-C isn't cropped, nor is it the same thing as a crop, because -- and this is the crux of the question, or the problem -- the sensors are not the same.
John,
Okay! Here's the further explanation. All lenses project a circular image inside the camera. Basically a 50mm lens is a 50mm lens because it projects an image circle 50mm in diameter. A 100mm lens projects an image circle 100mm in diameter, although clearly there are exceptions such as wide-angle lenses. Also lenses can be optimised in the design process for better performance at particular f stops or a specific range of f stops and for better performance closer to the centre than to the edges.

When I use a 50mm lens with a full frame 35mm format camera, the diagonal of the FF sensor (24mmx36mm) is approx 44mm. I'm essentially cropping a circular image 50mm in diameter to get a rectangular field of view with a diameter of 44mm. That's not a sigfnificant crop, but a crop nevertheless.

When I use that same 50mm lens with, say a Canon D60, I'm unavodably cropping the circular image (50mm in diameter) to a much greater degree. The diagonal of the APS-C sensor is approx 29mm. Place a rectangle with diagonal of 29mm against a circle with diameter of 50mm and you should appreciate just how much cropping is taking place.

Now I could keep on cropping that 50mm circle by using an even smaller sensor (such as the Oly 4/3rds sensor), or I could achieve the same effect by cropping the image in Photoshop. There's essentially no limit to the amount of cropping I could do. Want a cheap 1200mm lens? No problem. I'll take a shot with a 1Ds2 with a 50mm lens and crop the 24mmx36mm image to 1mm x 1.5mm in Photoshop. Voila! Same FoV as a 1200mm lens.

I've taken an extreme example, but the principle is sound (unless BJL would care to dispute this  :D ).

However, it sometimes takes an extreme example to clarify a point. I think it should be easy to appreciate that any image so severely cropped to achieve the same FoV as one would get actually using a 1200mm lens is not going to be anywhere near the same quality.

Likewise, one can't expect a 50mm lens on a D60 to produce image quality as good as an 80mm lens on a 1Ds2. Because these two cameras have the same pixel density, there is no image quality advantage for the D60 under any circumstances with any lens that might fit both cameras. There are only image quality disadvantages for the D60.

The notion that a 600mm lens on a D60 is equivalent to a 960mm lens on a 1Ds2 is pure illusion. However, a 600mm lens on a D60 will produce an image of equal quality and FoV after the 1Ds2/600mm image has been cropped in Photoshop to the same size.

Now you might ask, why would one want to crop the 1Ds2 image? Well, if that's your longest lens and you are shooting wildlife there might well be no option. The point here is that nothing would be gained by using a D60 for the same shot. Cropping is cropping, whether it's done by the camera or in Photoshop.
Title: the so called minuature formats
Post by: dturina on September 30, 2005, 08:16:47 am
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The notion that a 600mm lens on a D60 is equivalent to a 960mm lens on a 1Ds2 is pure illusion. However, a 600mm lens on a D60 will produce an image of equal quality and FoV after the 1Ds2/600mm image has been cropped in Photoshop to the same size.

Now you might ask, why would one want to crop the 1Ds2 image? Well, if that's your longest lens and you are shooting wildlife there might well be no option. The point here is that nothing would be gained by using a D60 for the same shot. Cropping is cropping, whether it's done by the camera or in Photoshop.
None of this applies to Olympus ZD lenses. The term "cropping" applies to the lenses that draw bigger image circle, only the small central part of which is used. However, imagine a lens that draws a circle twice smaller, but *condenses* all the light and resolution from the large circle and contains it within the smaller. That is actually the case - ZD lenses are at least one full stop faster than the competition, and have twice the resolution, if published MTF charts are to be trusted. So, basically, while APS-C has a problem, 4/3 doesn't. The problem is the sensor; I doubt they'll manage to make a sensor with twice the resolution per surface, to utilize the extreme resolution of the lenses.
Olympus lenses are something different from the APS-C stuff, which usually targets the low end of the market. The Zuikos target the high end, sort of like Leica. They are expensive, but of highest quality. I recently tested a ZD 35-100 f/2 prototype, and it's a jewel. If Olympus can make a fast 12 MP body with image stabilization and good noise performance, it could be a dream system, because, realistically speaking, nobody really needs more than 12MP resolution in a small format camera. It would be enough for weddings, sports, photojournalism and wilidlife; only landscape photographers who used to shoot large format might complain.
Title: the so called minuature formats
Post by: keithrsmith on September 30, 2005, 09:11:41 am
" Basically a 50mm lens is a 50mm lens because it projects an image circle 50mm in diameter."

As far as I understand it this is not so

"For a thin double convex lens, all parallel rays will be focused to a point referred to as the principal focal point. The distance from the lens to that point is the principal focal length f of the lens."

The whole business of crop factors should be forgotten - the important issues are the angle of view of a lens and how many pixels are in the image (and how good the pixels are).

I agree that if Olympus manage to bring out an E1 replacement with 12Mpix it, coupled with the lenses such as the 150mmF2 etc, will be a great system.

Keith
Title: the so called minuature formats
Post by: Ray on September 30, 2005, 10:18:32 am
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None of this applies to Olympus ZD lenses. The term "cropping" applies to the lenses that draw bigger image circle, only the small central part of which is used. However, imagine a lens that draws a circle twice smaller, but *condenses* all the light and resolution from the large circle and contains it within the smaller. That is actually the case - ZD lenses are at least one full stop faster than the competition, and have twice the resolution, if published MTF charts are to be trusted. So, basically, while APS-C has a problem, 4/3 doesn't. The problem is the sensor; I doubt they'll manage to make a sensor with twice the resolution per surface, to utilize the extreme resolution of the lenses.
I take your point and in the absence of reliable test data I cannot make much of an argument here except to point out one or two anomalies.

The finest and most expensive Zuiko lens for the 4/3rds format is the 300/2.8. This lens is actually heavier than Canon's 300/2.8, slightly more expensive and does not have the benefit of IS. Since the 300/2.8 IS is also one of the finest lenses that Canon produce, if not the finest, I would find it difficult to accept that the Zuiko 300mm would be any more than marginally better.

The notion that a lens designed for a smaller format 'condenses' what might otherwise be a large image circle into a much smaller image circle of inversely and proportionally higher resolution has been debunked by BJL. (And he's the lens expert  .) If I've understood him correctly, he says that beyond about 60mm the image circle increases in proportion to focal length and the telephoto effect is basically achieved by the equivalent of a built-in teleconverter which enlarges the central portion of the image circle with some consequent degradation that we associate with all add-on teleconverters, but clearly not to the same degree.

However, there is a significant factor here in relation to DoF when comparing lenses of different focal length to achieve equal FoV with the different formats; something which BJL keeps harping on, but it seems to me this is only relevant because of current discrepancies in pixel densities between full frame and the smaller formats.

To illustrate this point, let's look at what happens with 2 different formats of the same pixel density, the D60 and 1Ds2, when both are used with a standard 50/1.4 lens.

Conventional wisdom says the D60 will exhibit more DoF at the same aperture provided the shooting distances are different so as to achieve the same FoV. Ie. if I was really impressed with the shallow DoF of the 50/1.4, I'll be slightly disappointed when using that lens on a D60. On the other hand, if I was often disatisfied with the DoF I got with full frame 35mm at f11, I'd be pleasantly surprised at the performance of the D60 at f11.

When dealing with different formats of the same pixel density, it's all smoke and mirrors. There's no DoF advantage of the smaller format. The option is always there, with the larger format, to sacrifice the resolution advantage to achieve equal DoF (and equal resolution) at the same aperture and FoV, through a process of cropping.
Title: the so called minuature formats
Post by: John Camp on September 30, 2005, 10:58:33 am
Ray,
I think we must be talking past each other, and are simply using "crop" in different ways.

You seem to be arguing (or I may be misunderstanding you) that if you take a 1dsII shot with a 100mm lens, and a D2x shot with a 100mm lens, make prints showing the same FOV at the same print size, you will have essentially the same prints.

I am saying that if you do that, the D2x print will look like it was made from ASA 100 color film, and the 1DsII will look like it was made from ASA3200 color film. (This would not be exact, but you get the idea: the ASA 100 film would be way, way sharper with much better resolution and less noise.)

If you agree with that, then we have no difference; our difference has been purely semantic. I don't, however, agree with your use of the word "crop," although I know it's been used that way by zoom-lens users, who talk about making an "in-camera crop" by zooming in closer to a subject.

For me, a crop has always meant throwing away information captured on a negative or a sensor in the production of a final print. No information is thrown away on an in-camera crop; only the fov changes, and you still get the full resolution that your lens/film lens/sensor system is capable of offering.

JC
Title: the so called minuature formats
Post by: Ray on September 30, 2005, 11:38:11 am
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For me, a crop has always meant throwing away information captured on a negative or a sensor in the production of a final print.

John,
If that's the case then you have not understood the entire 'crop factor' issue as it applies to the APS-C format.

Whether or not you describe the different lens requirements of the Canon D30, D60, 10D, 20D etc as a 1.6x focal length multiplier, or as a 1.6x crop factor is just a matter of semantics. I'm easy with both descriptions. I just don't think one should lose sight of the fact that an APS-C camera attached to a full frame 50mm lens (for example) throws away considerably more picture information than does the full frame camera. And the same applies to any 35mm lens you attach to the APS-C format.

If you define cropping as throwing away picture information, then you've got it by default with the APS=C format.
Title: the so called minuature formats
Post by: Ray on September 30, 2005, 12:01:34 pm
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The whole business of crop factors should be forgotten - the important issues are the angle of view of a lens and how many pixels are in the image (and how good the pixels are).

What about the MTF response of the lens at a particular resolution? Do you think that's important? And please tell me what consumer grade cameras you know of that employ a 'thin double convex' lens. I don't consider myself to be an expert on lens design and I'd like to know.
Title: the so called minuature formats
Post by: BobMcCarthy on September 30, 2005, 12:09:12 pm
The whole issue of crop sensors just doesn't ring true the way its discussed. It's as if a crop sensor just gives less.

I would like to offer the comment that "ALL' lenses give excess coverage. My 240mm symmar nearly covers 8x10 at infinity, yet it's rarely used that way. Why, well 8x10's are rare as hen's teeth compared to the 4x5 and secondly the lens changes in character as one focuses. The image circle enlarges as one focuses closer. So we're talking about surplus coverage. The 240 focused on a 8x10 at infinity suffers poor edges and light fall off. Sharpness is less than stellar at the edges(however on a contact print, its still #### good) as sharpness tends to fall off the further from the optical center. Pull the bellows out and the edges clean up nicely.

Using the same lens on a 4x5 is an entirely different issue, sharp edge to edge, plenty of coverage for tilt, shift etc. Its works well because we have "SURPLUS" quality (call it sharpness, resolution, contrast whatever). Using less than full coverage is common to all formats from mini to maxi. Therefore "all" cameras are crop camersa

Quality of a lens in most designs is a series of compromises, certainly cost being one of them and throughout history (mine anyway) we always expected lens quality/capability to fall off in the corners. The other corrolary is the center will be much sharper, in most HQ optics a "surplus" compared to the film/sensor( it took micro fine grain film to get a sense of ultimate resolution) so we were sensor (film) limited.

So as I read the MTF charts on teles and long normals, there is a nice distribution of lens quality, nearly out to the edge of the image circle. So if the lens has enough surplus to get all out of a sensor, what else is needed. Teles work fine for 35mmFF or DX with acceptable lens capability. Other factors dominate that part of the discussion, i.e. weight, aperture, etc.

Wides are another issue. High resolution 35mmFF are on the ragged edge as the sensors are now the limiting factor. It can be acceptable, but Canon doesn't currently have the solution and they are the only purveyer of FF cameras at present. Apparently Zeiss has a good design, at least from what I read, but now we're dealing with stop down metering, adaptors etc. Still it shows what can be done. All at great expense for the customer/fan of FF.

Smaller sensors with optimized lenses can equally/esentially work well. As long as the sensor and lens are designed to coexist well, an equally good solution is available. Wide angle 35mm lenses on Dx lose there wideness so DX lenses MUST be provided.

The point of all this is we are discussing issues already identified and solutions being worked on. It is not Canon (FF) vs Nikon (DX) & Canon (APS-C). Canon is in full frame, entirely due to marketing and image. The dollars generated are a drop in the sea compared to the vastness of their other enterprizes and formats. Pretty effective and many of you all are surely convinced.

Nikon has a more elegant solution from my perspective. High density sensors doing more are on the correct side of Moores Law not reducing the cost of silicon platters and chip yield.

In-camera processing is in it,s relative infancy and will make high density sensors much more capable going forward.

Some ask, why I have switched partys. I have been known to carry a brand C camera for 30+ years.

I like Nikon "Color" in the D2x. I prefer it over the competitors.

I had a ton of FD "L"'s that Canon obsoleted and I enjoy using older mf lenses. (I'm using 30yr old AIS Nikkors now)

The D2x has so much excess sharpness and enlargeablility that I wouldn't even concider a larger format camera at this point, that included FF35mm.

4x5 film still represents the ultimate in image quality at an affordable cost.

And DX will always provide acceptable quality at a lower lost or more features for the dollar.

bob
Title: the so called minuature formats
Post by: Ray on September 30, 2005, 12:32:21 pm
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And DX will always provide acceptable quality at a lower cost or more features for the dollar.

Maybe so. But if the price difference gets closer, then the buying patterns change. If I have a choice between a 20D at $1500 and a 1Ds2 at $8,000, I don't have to think too hard. If I have a choice between a 20D and a 12mp 5D at $3000, I'm going to be tempted to buy the 5D. If the price gap narrows further, I'm almost certainly going to buy the full frame. The 5D is already cheaper than the D2X, by the way. We've yet to discover whether it has lower noise at high ISOs.
Title: the so called minuature formats
Post by: BobMcCarthy on September 30, 2005, 01:32:35 pm
What if you had a choice between a $3000 5D (13mpxl) and a $1500 30D (13mpxl). A pro might go for a 35FF but 90% would go for the reduced format.

Or a $2000 35D (13mpxl) but now with some pro features (weatherproof/metering/focus).

Nikon/Sony certainly doesn't have a lock on HD sensors

Bob
Title: the so called minuature formats
Post by: keithrsmith on September 30, 2005, 02:51:51 pm
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Quote
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The whole business of crop factors should be forgotten - the important issues are the angle of view of a lens and how many pixels are in the image (and how good the pixels are).

What about the MTF response of the lens at a particular resolution? Do you think that's important? And please tell me what consumer grade cameras you know of that employ a 'thin double convex' lens. I don't consider myself to be an expert on lens design and I'd like to know.
Agreed the MTF is a major factor - across the whole image plane etc.

the point about focal length is that I don't think it's the size of the image circle, its to do with the distance from the lens to to focal point for any lens construction.

Someone tell me if I'm wrong.

Keith
Title: the so called minuature formats
Post by: Bobtrips on September 30, 2005, 03:17:17 pm
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What I did mind in this whole thing, at least watching the Olympus SLR forum on dpreview, is that Michael was again unfairly attacked, as if he insulted a leader of some cult, and now the followers are out for revenge. The similar thing happened to Mike Johnston, and now he stopped writing his columns, which is a great loss for the photographic community. People take cameras way too seriously, it seems.
There's way too much brand/format/medium loyalty.  Far too people are able to discuss issues in a logical and non-emotional manner.  I suspect a lot has to do with the fact that many people have a limited equipment budget, perhaps have pushed their budget to obtain their current gear.

I certainly think that a lot of the earlier film vs. digital anger was engendered by the fact that many people had invested a lot of effort in acquiring shooting and darkroom skills that were now becoming obsolete.

Michael has a tendency to be a 'first responder', is quite visible, and tends to draw a lot of the "Kill the Messenger" fire.  I appreciate his willingness to get out front and take the flack.  I'd hate to see him pull back.

OTOH I appreciate what DPR brings to the table.  First there are the more 'technical' reviews.  Then there's the larger/wider group of participants.  Sure they are more rowdy and sometimes just plain jerks.  (Not that this site doesn't entertain a jerk or two. ;o)  But DPR brings a different type of participant to the table.  I learn lots of stuff from both sites.

BTW, if you feel that someone is really out of line on DPR send Phil a email.  Folks get banned from the site quite frequently for misbehavior.
Title: the so called minuature formats
Post by: BJL on September 30, 2005, 05:39:43 pm
Ray is mostly right that any image you can get with a certain focal length (like 300mm) in one format, you can get about equally as well using the same focal length with a sensor that is larger and yet has the same pixel size, by cropping.

But the image quality will not be the slighter bit better, and ther are downsides to the larger sensor, same focal length approach:

a) Cost.
You are paying for and carrying a more expensive camera.

 Viewfinder crop.
Comparing 24x36 format to DX, EF-S, or Four Thirds, the image that you want after cropping occupies only one half to one quarter of the larger format's viewfinder area. Also, with all current and recent DSLR's, the desired part of the image will be smaller, because teh smaler format DSLR's have higher viewfinder magnification at equal focal length (e.g. 1x @ 50mm for the Olympus E-300 vs 0.72x @ 50mm for all Canon EOS 24x36mm format cameras, film and digital.)

c) Lower sensor resolution (lp/mm).
All 24x36mm DSLR's have lower pixel density than even quite cheap smaller format DSLR's, and the gap has ben steadily growig not decreasing, with teh pixel counts instead getting closer. The 5D is 8.2 microns and the 1DS is over 7 microns, while the 20D is 6.4 microns, the new Sony CMOS sensors are 5.5 microns and the E-300 and E-500 are 5.3 microns. So that cropping from the same focal length will give you far less resolution with the larger format.
Ray will probably just assert that this is going to change, offering no evidnce and ignoring th evidence of trends in the opposite direction.

The inherently lower resolution (lp/mm) or larger format lenses is probably a factor in this leveling out of pixel counts. Many Canon lenses are apparently already getting to be limiting factors at 16MP, while even Four Thirds can easily go beyond that pixel count if needed.

d) Flare control
An optimal telephoto lens designed for a smaller format will be slightly different, in that its lens hood and internal anti-flare baffles will have smaller openings, accepting light form only a narrower angular fild of view. This can reduce flare, particularly if a bright light source is just outside the desired FOV, but within the uncropped FOV of the larger format.

So once again, using a lens designed for the job at hand is likely to have an advantage over the "hack" of using a lens designed for a somewhat different task: forming a larger image on a larger sensor or piece of film.
Title: the so called minuature formats
Post by: BJL on September 30, 2005, 05:58:12 pm
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The notion that a lens designed for a smaller format 'condenses' what might otherwise be a large image circle into a much smaller image circle of inversely and proportionally higher resolution has been debunked by BJL.
Ths is slightly out of context. That is mostly true with long enough telephoto lenses like your rather extreme 300mm example. (By the way, why use such an extem example by the way? Why consider the most expensive and low selling of all the new Digital lenses instead of a more typical ones like the Olympus 50-200 f/2.8-3.5?)

On the other hand, some normal to wide lens designs for smaller formats do more or less use this "condensing" approach: they add extra convergence in the rear lens elements, so shrinking the larger image formed by the front elements, with the three effects of
a) reducing focal length, maintaining angular FOV over a smaller image circle
 reducing the aperture ratio, making the lens "brighter". Over one stop brighter if going from 35mm to APS-C, and almost two f-stops if going all the way to Four Thirds.
c) raising the exit pupil height, making the lens more telecentric, and so more compatable with standard modern elecronic sensors.

The new Zuiko Digital 35-100 f/2 seems to be an example, as its design resembles a 50-150 f/2.8 at the front with a 1.4 focal reducer at the back: 35-100 f/2 PRO ED Zoom page (http://www.olympusamerica.com/e1/sys_lens_35_100mm.asp)
That "50-150 f/2.8" front design could in turn have been created from a 70-200 f/2.8 35mm format design by scaling down by a factor of about 1.4x. Each of those two downsizing steps shrinks the abberations of the putative 35mm format parent design, so such an approach should give this Four Thirds format lens about twice the resolution (lp/mm) of that putative 35mm format parent.
Title: the so called minuature formats
Post by: BJL on September 30, 2005, 06:02:36 pm
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There is another reasons for wanting to stop down, and that is to control shutter speed.
For the relatively rare cases when one needs such a low shutter speed that not even minimum ISO can give you, using ND filters seems a far more economical approach than buying a far bigger, more expensive sensor.
Title: the so called minuature formats
Post by: Ray on September 30, 2005, 10:44:42 pm
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But the image quality will not be the slighter bit better, and ther are downsides to the larger sensor, same focal length approach:

a) Cost.
You are paying for and carrying a more expensive camera.

BJL,
I don't think anyone has tried to make the point that larger format cameras are not more expensive. This debate has been sparked by a narrowing of the price gap with the introduction of the 5D and a likelihood that the trend will continue. If over all cost and weight are your main concerns then you will be amply served by a plethora of P&S choices that already include a 10 megapixel APS-C sensor.

Quote
Viewfinder crop.
Comparing 24x36 format to DX, EF-S, or Four Thirds, the image that you want after cropping occupies only one half to one quarter of the larger format's viewfinder area.

This is not an insurmountable problem, BJL. Viewfinder attachments for those who wish to simulate a longer focal length could be either optional accessories or included with the camera. Ideally, the larger format viewfinder could contain a number of mattes at the press of a button and a zoom function at the press of another button to fill the viewfinder with any one of the matte sizes.

Quote
c) Lower sensor resolution (lp/mm).
All 24x36mm DSLR's have lower pixel density than even quite cheap smaller format DSLR's, and the gap has ben steadily growig not decreasing, with teh pixel counts instead getting closer. The 5D is 8.2 microns and the 1DS is over 7 microns, while the 20D is 6.4 microns, the new Sony CMOS sensors are 5.5 microns and the E-300 and E-500 are 5.3 microns. So that cropping from the same focal length will give you far less resolution with the larger format.
Ray will probably just assert that this is going to change, offering no evidnce and ignoring the evidence of trends in the opposite direction.

I'm not going to ignore evidence of trends in the opposite direction. I'm far too objective and unbiased for that, BJL  :D .

What I have observed is an over all trend to higher pixel density across all formats without exception and an incessant concern on the part of some photographers that their lenses are not good enough to take advantage of that higher resolving capacity of the higher pixel density sensor.

The D2X demonstrated there's still some resolution advantage to be had from greater pixel density. I therefore think it's likely we will eventually see 32MP full frame sensors. The point has also been raised by yourself that over sampling could be a viable technique of extracting the maximum amount of detail and resolution a lens can offer.

Quote
So once again, using a lens designed for the job at hand is likely to have an advantage over the "hack" of using a lens designed for a somewhat different task: forming a larger image on a larger sensor or piece of film.

Or to look at it another way, the performance of the smaller format might eventually be just a subset of the larger format. There's nothing the smaller format can do that the larger format can't, except be lighter and cheaper, but there's plenty the larger format can do that the smaller format can't.  :D
Title: the so called minuature formats
Post by: Ray on October 01, 2005, 04:06:41 am
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Ths is slightly out of context. That is mostly true with long enough telephoto lenses like your rather extreme 300mm example. (By the way, why use such an extem example by the way? Why consider the most expensive and low selling of all the new Digital lenses instead of a more typical ones like the Olympus 50-200 f/2.8-3.5?)

Why? Because the lenses are so exactly equivalent in all respects and both represent the pinnacle of lens excellence from both companies for their respective formats. When or if pixel density exceeds the resolving capability of both lenses (ie. an oversampling situation exists for both sensors, to obviate the need for an AA filter), then these two lenses will reveal more clearly the differences betweeen the two formats, their advantages and disadvantages. Those who claim there's an inherent price and weight advantage of the smaller 4/3rds format without any sacrifice of image quality might find it ain't so  :D .

I've got no reliable information on the other zoom lenses you've mentioned. There are too many variables. Comparing 'inherent' advantages of different formats by using lenses of unknown, variable or simply different quality, gets us nowhere.

However, there's something to be said for choosing a system to match lenses which you know are impressive. A good lens is like a jewel, something to be treasured, but for me the math simply doesn't add up. Most of those Zuiko lenses might be a cut above their Canon equivalent but to achieve the same image quality as 35mm is capable of, their MTF response has to be at least equal at double the frequency, ie. the 150mm Zuiko prime that produces the same FoV as the Canon 300/2.8, needs to have an MTF response at 60 lp/mm that's as high as the Canon lens at 30 lp/mm, an MTF response at 80 lp/mm that's as high as the 300/2.8 IS at 40 lp/mm and a response at 20 lp/mm that's as high as the Canon lens at 10 lp/mm.

I think that's too much to expect, don't you? - not to mention the additional noise of the smaller 4/3rds pixels if we are comparing equal picture height resolution.
Title: the so called minuature formats
Post by: dturina on October 01, 2005, 09:33:47 am
Quote
Most of those Zuiko lenses might be a cut above their Canon equivalent but to achieve the same image quality as 35mm is capable of, their MTF response has to be at least equal at double the frequency, ie. the 150mm Zuiko prime that produces the same FoV as the Canon 300/2.8, needs to have an MTF response at 60 lp/mm that's as high as the Canon lens at 30 lp/mm, an MTF response at 80 lp/mm that's as high as the 300/2.8 IS at 40 lp/mm and a response at 20 lp/mm that's as high as the Canon lens at 10 lp/mm.

I think that's too much to expect, don't you? - not to mention the additional noise of the smaller 4/3rds pixels if we are comparing equal picture height resolution.


It's difficult for me to read the manufacturer's MTF charts with full understanding, as they seem to measure things at different line pair frequencies. However, we have two MTF charts here,
ZD 150mm f/2 (http://www.olympus-esystem.com/dea/products/lens/150_20/mtf.html)

and Canon EF 300mm f/2.8 IS (http://consumer.usa.canon.com/ir/controller?act=ModelDetailAct&fcategoryid=154&modelid=7317)

From what I can read, 150mm f/2 has stunning performance at 60 LP, wide open. I have more difficulty reading the Canon chart, as it isn't as well explained, so I can't really tell. I can tell, however, that they both have excellent edge-to-edge sharpness and insane amounts of resolution.
Title: the so called minuature formats
Post by: bob mccarthy on October 01, 2005, 09:41:12 am
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Or to look at it another way, the performance of the smaller format might eventually be just a subset of the larger format. There's nothing the smaller format can do that the larger format can't, except be lighter and cheaper, but there's plenty the larger format can do that the smaller format can't.


Thats always been true, whether we're talking about

sheet film vs. roll (4x5 vs.2 1/4)

roll vs. cassette (2 1/4 vs 35mm)

digital format (35FF vs DX )

The only difference in the last example is that they share infastructure (lens, focus, metering, flash, etc). I believe they need to be seen in the context of different formats.

Does the format meet your needs and/or customer requirements?

My "only" negative with FF is the lens systems are challenged at the wide end (the format is sensor limited in the center and lens limited at the edges). And there has always been a cost premium for utilizing a larger format. DX Image quality (using the high end D2x example, other DX need not apply) is just as capable at the current time as FF.

There is one more negative, but its not format related, and thats the huge quantity of data we're collecting (storing, manipulating,etc), with both formats reaching a point it's overkill for all typical output with the sole execption of "very" large prints.

We are close to the endgame?

If so, that tends to point at economics, not ultimate capability as the principle driving force.

Bob
Title: the so called minuature formats
Post by: Ray on October 01, 2005, 12:09:28 pm
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From what I can read, 150mm f/2 has stunning performance at 60 LP, wide open. I have more difficulty reading the Canon chart, as it isn't as well explained, so I can't really tell. I can tell, however, that they both have excellent edge-to-edge sharpness and insane amounts of resolution.
The Canon charts have the thick lines representing contrast at 10 lp/mm and the thin lines 30 lp/mm. Black are at maximum aperture and blue at f8.

What I see here are thick black lines at virtually 100% MTF on the Canon chart, falling off just a bit towards the edges. This is clearly a better response than the Zuiko 150/2 at 20 lp/mm.

If we take an average of the thin solid black line and thin dotted black line, representing 30 lp/mm at full aperture, we find that it's mostly above 90%, falling below only towards the edges. If we take the better of the two lines at 30 lp/mm, the solid thin line representing sagittal resolution (like the spokes of a wheel), we find that sagittal resolution at 30 lp/mm is actually better than the Zuiko at 20 lp/mm.

What I can say in praise of the Zuiko chart is the meridional and sagittal lines do not diverge as much as in the Canon chart which I believe is indicative of better bokeh and less astigmatism, but the contrast at both 20 lp/mm and 60 lp/mm is simply not high enough for this lens to compete with the Canon 300/2.8. Of course it's a cheaper and lighter lens. It's also a stop faster, so it's got its advantages.
Title: the so called minuature formats
Post by: Ray on October 01, 2005, 12:57:25 pm
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Thats always been true, whether we're talking about

sheet film vs. roll (4x5 vs.2 1/4)

roll vs. cassette (2 1/4 vs 35mm)

digital format (35FF vs DX )

The only difference in the last example is that they share infastructure (lens, focus, metering, flash, etc). I believe they need to be seen in the context of different formats.


That sharing of infrastructure is very significant. When the difference in price between a full frame body and an APS-C body is no more than the cost of an average zoom lens, it doesn't make much sense to deprive yourself of the full performance of all your lenses, including increased FoV on your wide angle lenses, for the sake of a few bucks.

However, the 4/3rds system doesn't share infrastructure with another format so I suppose there are better reasons for that format to survive than there are for the 'cropped' 35mm format.
Title: the so called minuature formats
Post by: dturina on October 01, 2005, 02:40:03 pm
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Quote
From what I can read, 150mm f/2 has stunning performance at 60 LP, wide open. I have more difficulty reading the Canon chart, as it isn't as well explained, so I can't really tell. I can tell, however, that they both have excellent edge-to-edge sharpness and insane amounts of resolution.
The Canon charts have the thick lines representing contrast at 10 lp/mm and the thin lines 30 lp/mm. Black are at maximum aperture and blue at f8.

What I see here are thick black lines at virtually 100% MTF on the Canon chart, falling off just a bit towards the edges. This is clearly a better response than the Zuiko 150/2 at 20 lp/mm.

If we take an average of the thin solid black line and thin dotted black line, representing 30 lp/mm at full aperture, we find that it's mostly above 90%, falling below only towards the edges. If we take the better of the two lines at 30 lp/mm, the solid thin line representing sagittal resolution (like the spokes of a wheel), we find that sagittal resolution at 30 lp/mm is actually better than the Zuiko at 20 lp/mm.

What I can say in praise of the Zuiko chart is the meridional and sagittal lines do not diverge as much as in the Canon chart which I believe is indicative of better bokeh and less astigmatism, but the contrast at both 20 lp/mm and 60 lp/mm is simply not high enough for this lens to compete with the Canon 300/2.8. Of course it's a cheaper and lighter lens. It's also a stop faster, so it's got its advantages.
The problem is, Canon has measurements for both f/8 and wide open, and from their glossary file it seems they measure 10 and 30 line pairs. Zuiko has 20 and 60 line pairs graphs, wide open only. If that is the case, a comparison is difficult to make, especially since Canon's chart consists of apparently 8 lines, and they aren't that intuitively colored. Olympus chart is very easy to read.

ps: ignore me; I just saw that I basically said the same things you did - it's obviously past my bedtime.
Title: the so called minuature formats
Post by: LesGirrior on October 01, 2005, 05:24:08 pm
All I know is how awesome my 8x10 prints look with my 6mp dSLR compared to the film I was shooting before, and with small, light, cheap equipment.

Its a great time to be a photographer on a budget, and its only getting better.
Title: the so called minuature formats
Post by: Ray on October 01, 2005, 10:39:42 pm
Of course, to be fair to BJL, he has already conceded that telephoto lens design cannot provide the extra quality necessary to compensate for the smaller sensor, so comparing a Zuiko 150mm lens with a Canon 300mm merely confirms this fact.

If we examine the other end of the range, the situation is quite different, but I'm not sure if the reason is that Canon simply do not make high quality wide-angle lenses.

The Zuiko 7-14mm F4 seems to be so good I feel like buying an E-500 just so I can use this lens. The nearest Canon equivalent is the 16-35/2.8. The Zuiko has the advantage of being slightly wider. The Canon has the advantages of being one stop faster, lighter (surprisingly) and cheaper.

The MTF charts for these two lenses are here (http://www.olympus-esystem.com/dea/products/lens/7-14_40/mtf.html) and there (http://consumer.usa.canon.com/ir/controller?act=ModelDetailAct&fcategoryid=148&modelid=7487) .

The thin solid and dashed lines on the Canon charts represent contrast at 30 lp/mm. The orange lines on the Zuiko chart represent contrast at 60 lp/mm. If the Zuiko MTF response at 60 lp/mm is as high as the Canon MTF response at 30 lp/mm, we could claim that the Zuiko lens has double the resolution, which it needs to have if the 4/3rds system is ever to equal the image quality of FF 35mm.

Examining these charts at equivalent distances along the x-axis, ie. comparing response at 2.5mm from the centre for the Zuiko with 5mm from the centre for the Canon and so on, it seems to me that the Zuiko has more than double the resolution of the 16-35, ie. on the whole its response at 60 lp/mm is actually better than that of the Canon at 30 lp/mm.

Dear me, Canon. You really will have to lift your game otherwise Olympus will steal the show .

I wonder if there's any way I could fit this lens to my 20D? The MTF response is so flat, the fall-off at the edges of the slightly larger 20D sensor might not be noticeable.
Title: the so called minuature formats
Post by: dturina on October 02, 2005, 04:31:58 am
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Dear me, Canon. You really will have to lift your game otherwise Olympus will steal the show  :D .
Yes, ZD 7-14 seems to be a stellar performer. I probably won't buy it since I seldom need wide angle, and 11-22 would be a more compact choice (and it uses the same filter size as my standard lens).
Will Olympus become a serious contender? It might all depend on the E1 successor. If it's a camera in the D2X league, it will equal medium format film in resolution, and this might be just enough for 99% of people. The prevalent roumor says it will have in-body image stabilization, too, and it might be pretty fast in operation, as it isn't that difficult to make a quick camera nowadays. If it all comes together, hopefully without major warts such as noise, I don't see why Olympus wouldn't compete with Nikon for the second place. I don't think Canon's position is in question, though, they seem to be too far ahead, and their customer base is too broad. In the meantime, they painfully lack a flagship body, and introduction delays don't seem to help their lens sales.
Title: the so called minuature formats
Post by: Ray on October 02, 2005, 10:39:53 pm
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Yes, ZD 7-14 seems to be a stellar performer.
"Seems" is the key word here. The MTF charts look too good to be true. There seems to be no adaptor available to fit Zuiko 4/3rds lenses to other cameras, although there are adaptors available to fit other lenses to a 4/3rds body.

There seems to be no full res sample images available from the 7-14, no crital reviews, no independent tests and comparisons, just a lot of announcements about the lens being available in March 2005.

The only sample images I could find were low to medium res jpegs that give no clue whatsoever as to the quality of the lens.

What's going on?
Title: the so called minuature formats
Post by: dturina on October 03, 2005, 04:10:42 am
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Yes, ZD 7-14 seems to be a stellar performer.
"Seems" is the key word here. The MTF charts look too good to be true. There seems to be no adaptor available to fit Zuiko 4/3rds lenses to other cameras, although there are adaptors available to fit other lenses to a 4/3rds body.

There seems to be no full res sample images available from the 7-14, no crital reviews, no independent tests and comparisons, just a lot of announcements about the lens being available in March 2005.

The only sample images I could find were low to medium res jpegs that give no clue whatsoever as to the quality of the lens.

What's going on?
I saw pictures made with it on www.myfourthirds.com , and talked to people who own it, and what they say seems to be in agreement with that chart. There are absolutely no flaws, chromatic or geometric, that I heard of. It seems to be as good as they say. However, it's pretty heavy and bulky, similar to the 12- mm Sigma zoom, with the protruding front element, probably quite prone to scratching if you stick it into things, as people tend to do with ultrawides.
Title: the so called minuature formats
Post by: Ray on October 03, 2005, 05:15:48 am
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it's pretty heavy and bulky, similar to the 12- mm Sigma zoom, with the protruding front element, probably quite prone to scratching if you stick it into things, as people tend to do with ultrawides.
That wouldn't worry me too much. I'm used to a heavy and bulky Sigma 15-30mm which, on FF 35mm, is pretty close to the much more expensive Zuiko 7-14mm.

When it comes to assessing the quality of a lens, we either need objective tests such as those that Photodo used to do, or direct comparisons with other lenses we know and think highly of.

Unfortunately, the much praised Zuiko lenses for the 4/3rds format can only be used with 4/3rds camera bodies, so any sample images reflect the 'system' quality rather than the lens quality.

Since the latest 4/3rds cameras are now 8mp, and since this 7-14mm lens appears to be so much better than the run-of-the-mill Sigma 15-30 and Canon 16-35, I think a comparison would be appropriate with the latter two mentioned lenses on a 12mp Canon 5D.

Such a comparison would be very informative. Would we get, say 'over all' equal results, indicating that you really do get what you pay for (Canon 5D + above Sigma or Canon lens costing approx. the same as a 7-14mm + E-300), or would the FF 35mm with cheaper lens be obviously better?

These are the sorts of comparisons that interest me. I wonder how long we'll have to wait for them  :) .
Title: the so called minuature formats
Post by: dturina on October 03, 2005, 05:24:03 am
Ray, I found a link with samples for you - E300 with ZD 7-14:
http://dc.watch.impress.co.jp/cda/review/2...03/22/1182.html (http://dc.watch.impress.co.jp/cda/review/2005/03/22/1182.html)

It's not exactly a lab test, but anyway.
Title: the so called minuature formats
Post by: dturina on October 03, 2005, 06:02:59 am
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Ray, I found a link with samples for you - E300 with ZD 7-14:
http://dc.watch.impress.co.jp/cda/review/2...03/22/1182.html (http://dc.watch.impress.co.jp/cda/review/2005/03/22/1182.html)

It's not exactly a lab test, but anyway.
Here's some more:
http://www.pbase.com/enradman/olympus714 (http://www.pbase.com/enradman/olympus714)

If only they could make a body to match the glass...
Title: the so called minuature formats
Post by: Ray on October 03, 2005, 06:26:42 am
Thanks for that link, dturina. I've downpoaded a couple of images and they are certainly quite impressive with regard to straight lines and lack of chromatic aberration.

As regards resolution, I can't tell without a direct comparison with another 'known' lens.
Title: the so called minuature formats
Post by: BobMcCarthy on October 03, 2005, 11:25:02 am
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Quote
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The only difference in the last example is that they share infastructure (lens, focus, metering, flash, etc). I believe they need to be seen in the context of different formats.


That sharing of infrastructure is very significant. When the difference in price between a full frame body and an APS-C body is no more than the cost of an average zoom lens, it doesn't make much sense to deprive yourself of the full performance of all your lenses, including increased FoV on your wide angle lenses, for the sake of a few bucks.

However, the 4/3rds system doesn't share infrastructure with another format so I suppose there are better reasons for that format to survive than there are for the 'cropped' 35mm format.

Hehe, well I actually see it the other way around. The 4/3 system is out there standing alone and requires a total committment, whereas, anyone with an "old" 35mm system, can dip their toe in first to test the water before plunging in. The barriers to entry are lower.

I think we all get lost in the sensor issue, where the findamental belief is that bigger is always better. The sensor size is way down on my list of desired traits. In fact I think it's largely irrelevant. I want enough pixels, with good color. From the many tests, that amounts to the 1DsII or D2x, and from most reviews they are nearly equivalent. The tipping issue for "me" is the ability to conveniently use manual focus lenses of extremely high quality w/o any real inconvenience (full metering). Plus I really like the Nikon body layout and controls.

The tiny pixels on the D2x make for an impressive image, sharp corner to corner at low ISO, where I typically shoot. I am slightly telecentric in my seeing so the FL multilpler is a plus. 50/1.4 is now a 75/1.4 which works for me.

I made my system decision based upon my needs.

Would I like to have a FF sensor. You betcha, I'm first in line if I can get more of what I already have. With the small pixel technology, I would expect it to be quite an advance over the current state of the art. My preference is for a "near" FF in the 1" by 1.2" format, as I like the old 8x10 / 16x20 print format best. A 1 inch tall by 1.2 inch across sensor would give me effective FF (no wasteful crop i.e. 645 vs 6 square)and 20+ mpxls with the D2x pixel. But we're talking expensive and no doubt massive overkill for the vast majority of amateur or professional photographers including me.

Cutting out the extreme edges would help the wide lenses cope. While Nikon wides have a good rep, I suspect they would suffer somewhat too with FF35mm. Its always about compromises.

Nikon doesn't listen anymore to me that my teenagers do, so its all hypothetical at this point.

Bob
Title: the so called minuature formats
Post by: BJL on October 03, 2005, 05:20:04 pm
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But the image quality will not be the slighter bit better, and ther are downsides to the larger sensor, same focal length approach:

a) Cost.
You are paying for and carrying a more expensive camera.

BJL,
I don't think anyone has tried to make the point that larger format cameras are not more expensive.
Ray, let me make this simple. I am addressing solely your comparison done assuming the use of equal focal length lenses in different DSLR formats. In that particular comparison, the clear, inherent cost advantage of a smaller sensor is not offset by any advantage whatsoever to using a larger sensor. Longer focal lengths are essential to getting an image quality advantage from a larger sensor.

And as to your comparisons using the Four Thirds 300/2.8: this debate is overall about the claim that 24x36mm is inherently superior to smaller DSLR formats in general, to the point that those smaller formats will all eventually fail except perhaps at the lowest price levels. Amongst those smaller format DSLR systems, Four Thirds is clearly a far smaller player than Nikon DX. (I am not one of deluded brand loyalists who thinks that the best choice for them must be the best choice for everyone. For example, I would prefer the D2X over any current E system body for pro. sports photography. Over any other DSLR in fact.)

So if you wish to prove that smaler DSLR formats are inevitiably inferior to 24x36mm, try comparing a Nikon DX DSLR like the D2X, equipped with a 200/2 or 300/2.8 or 400/2.8, to a Canon 24x36 body with whatever Canon lens seems the closest match. If you compare with D2X and 1Ds MkII bodies, I am tempted to suggest that the Canon lens should be limited to somewhat lower cost and weight, to compensate for the D2X's lower cost and weight!
Title: the so called minuature formats
Post by: BJL on October 03, 2005, 06:01:52 pm
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The Canon charts have the thick lines representing contrast at 10 lp/mm and the thin lines 30 lp/mm. Black are at maximum aperture and blue at f8.

What I see here are thick black lines at virtually 100% MTF on the Canon chart, falling off just a bit towards the edges. This is clearly a better response than the Zuiko 150/2 at 20 lp/mm.
Ray, I sugget rereading Michael's esay on unerstanding MTF, ncluding the following:
"generally speaking a lens whose thick lines (10 LP/mm) are above .8 on the chart should be regarded as having excellent image quality. Above .6 is regarded as "satisfactory". Below .6 is, well, below."

Translate 10lp/mm to 20lp/mm for Four Thirds (and perhaps increase it also for pixel counts that go beyonf 35mm film performance levels.)

Both the Canon 300/2.8 and Olympus 150/2 have such high MTF at 10lp/mm and 20lp/mm respectively that they are solidly in the "excellent" range, and one is unlikely to see any significant different in print quality as far as those measurements are concerned. (The same for the Olympus 300/2.8, which I thought was you preferred comparison to the Canon 300/2.8!) mainly this shows that extremely narrow FOV lens designs make it relatively easy to get good performance, so long as you are willing to pay enough for all the good optical glass needed.

It seems to me that this "MTF-peeping" tells us very little about which of these two excellent lenses is better than the other.

(As to "price-peeping" though, the Canon 300/2.8 costs about twice as much as the Olympus 150/2, in line with having double an aperture of twice the area and hence about twice the front element area, and so maybe twice as much glass needed.)

Then again, I could take a leaf out of your book and try to dismiss the Canon 300/2.8's MTF charts as you did the Olympus 7-14's: "The MTF charts look too good to be true." But I am not into special pleading for my chosen brand and against favorable evidence for products from another brand. Couldn't we just agree that at the top of the line, Canon, Nikon and Olympus are all offering excellent lenses?
Title: the so called minuature formats
Post by: BJL on October 03, 2005, 06:20:56 pm
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... for me the math simply doesn't add up. Most of those Zuiko lenses might be a cut above their Canon equivalent but to achieve the same image quality as 35mm is capable of, their MTF response has to be at least equal at double the frequency, ie. the 150mm Zuiko prime that produces the same FoV as the Canon 300/2.8, needs to have an MTF response at 60 lp/mm that's as high as the Canon lens at 30 lp/mm, an MTF response at 80 lp/mm that's as high as the 300/2.8 IS at 40 lp/mm and a response at 20 lp/mm that's as high as the Canon lens at 10 lp/mm.

I think that's too much to expect, don't you?
No, not if one understands lens design. Doubling focal length and doubling image circle diameter esentially requires doubling magnification, and thus abberation effects that show up at 60lp/mm with the shorter focal length will show up equally at 30lp/mm with the larger.

To put it another way, one way to downsize a 300mm lens design for 35mm format to a 150mm lens for Four Thirds format is a combination of (a) reducing or eliminating the magnification of the "built-in teleconverter" in the rear elements of a typical telephoto lens design, and ( adding a built-in focal reducer (as Olympus seemingly did with their 35-100 f/2 design). Each of these steps shrinks abberations about in proportion to the shrinking of image size, so the 60lp/mm MTF curve out to 11mm for the new lens will be very similar to the 30lp/mm MTF curve out to 22mm for the original design.


On point (a), Ray of all people seems quite aware of how much better sharpness is when you remove a teleconverter!

And brightness is better too! This downsizing by a factor of two would also makes the lens two stops faster, allowing the smaller format to use of one quarter the ISO speed in low light/high shutter speed situations. Ray, do you really persist in believing that larger formats can use the same ISO in high speed, low light, telephoto situations, despite the obvious trend towards the need to use higher f-stops with the longer focal length lenses needed?

Olympus seems to be taking a middle strategy relative to the heaviest and most expensive 35mm format lenses; Four Thirds lenses at half the focal length that are one stop brighter rather than two, and thus significantly lighter and cheaper but effectively one stop slower. (Or equally fast if used with one half of the pixel count.)
Canon is doing somethig similar, developing a new lighter, cheaper line of high quality f/4 "L" lenses along-side existing f/2.8L ones: 17-40 f4/L, 24-105 f/4L IS , 70-200 f/4L, 400 f/4L IS DO. A sensible response to greatly increased usable ISO speeds.
Title: the so called minuature formats
Post by: BJL on October 04, 2005, 02:22:29 pm
Quote
Of course, to be fair to BJL, he has already conceded that telephoto lens design cannot provide the extra quality necessary to compensate for the smaller sensor ...
When and wher edid I concede that? My rough summary is that increasing format size and focal length will in general bring at most a modest resolution improvement on equal sized prints ("lines per picture height"), which must be weighed against the increase in cost and weight.

From APS-C to 35mm format in DSLR's, that cost difference started out at $2,500 to $3,000 when the 1Ds ($8,000) and 14/n ($5,000) were up against the D1X ($5,500?), D100 ($2,000) and D60 ($2,000).

Now the cost difference is $2,000 to $2,700: $2,000 for 5D vs 20D), $2,300 for 1DsMkII vs D2X, $2,700 for cheapest 35mm DSLR (5D) vs cheapest smaller format DSLR (E-500?)
Title: the so called minuature formats
Post by: Ray on October 05, 2005, 12:10:21 am
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So if you wish to prove that smaler DSLR formats are inevitiably inferior to 24x36mm, try comparing a Nikon DX DSLR like the D2X, equipped with a 200/2 or 300/2.8 or 400/2.8, to a Canon 24x36 body with whatever Canon lens seems the closest match.
BJL,
Inferior? Superior? These are emotive terms. I'm certainly not trying to argue that formats smaller than 35mm are inferior. I'm simply making the point that 35mm is a more versatile tool. (If more versatile equates to superior in your mind, then so be it.) Digital FF 35mm produces the goods of sufficient quality to make big, exhibition size prints as well as small prints, yet is still reasonably light and convenient to use.

The 4/3rds system is ideal for smallish to medium size prints (say A3+ maximum), but might prove to be limited if you wanted to exhibit a largish print, say 18"x24".

If you are one of those people who claims to know that he/she will never buy a printer of larger format than the Epson 1280/90 or desire prints larger than A3+, then you might confidently buy an Olympus 4/3rds system, or indeed you might buy it as a second camera when weight is a problem and maximum quality is not an issue, although personally I would opt for the new Sony DSC R1 if I wanted something light and versatile yet still retaining good quality, for climbing a mountain for example.

However, if Olympus releases camera bodies with improved sensors of higher pixel density and lower noise, then some of their more expensive and heavier[/i] lenses (such as the 7-14/f4) might be able to take on a Canon 5D/ 16-35 combination at a similar price and weight, but I'm doubtful. By the time we get an Olypus 12mp body we'll probably have a 16mp (or more) 5D successor.
Title: the so called minuature formats
Post by: Ray on October 05, 2005, 01:27:20 am
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Ray, I sugget rereading Michael's esay on unerstanding MTF, ncluding the following:
"generally speaking a lens whose thick lines (10 LP/mm) are above .8 on the chart should be regarded as having excellent image quality. Above .6 is regarded as "satisfactory". Below .6 is, well, below."

BJL,
I had a fair understanding of MTF charts before Michael wrote that tutorial. However, having re-read the article at your suggestion I find the following relevant reference:-

Quote
the higher up the chart the 10 LP/mm line is (the thick lines), the higher the contrast reproduction capability of the lens will be.

Need I say more? Well, I will anyway. You are quite right in implying that the performance of a lens at 10 lp/mm is not critical to its ultimate resolution performance in large prints. It affects over all contrast which can in any case be corrected through Photoshop's USM, although it's clearly advantageous to start off with a an image that's already contrasty.

Nevertheless, the point cannot be stressed too loudly, if you want to make a large print that's sharp from close up, from a small sensor, then the resolution of the lens has to be greater to a degree inversely proportional to the size of the sensor.

My comparison of the MTF charts of the Zuiko 150/4 and the Canon 300/2.8 indicate that this condition has not been met by the Zuiko lens. The Zuiko 150/4 is a fine lens, but to compete with the Canon 300/2.8 (in conjunction with the 4/3rds sensor about 1/4 of the size) it needs to be an ultra superb lens, which it ain't.

Sorry! Facts of life.
Title: the so called minuature formats
Post by: Ray on October 05, 2005, 01:45:20 am
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No, not if one understands lens design. Doubling focal length and doubling image circle diameter esentially requires doubling magnification, and thus abberation effects that show up at 60lp/mm with the shorter focal length will show up equally at 30lp/mm with the larger.

Maybe with the same amount of resources for lens design and manufacture. But longer focal length lenses have a habit of being more expensive, often very much more expensive.

So it seems there are[/i] techniques of getting around those principles you've espoused, although at some considerable cost.
Title: the so called minuature formats
Post by: Ray on October 05, 2005, 03:27:02 am
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Quote
Of course, to be fair to BJL, he has already conceded that telephoto lens design cannot provide the extra quality necessary to compensate for the smaller sensor ...
Quote
When and wher edid I concede that? My rough summary is that increasing format size and focal length will in general bring at most a modest resolution improvement on equal sized prints ("lines per picture height"), which must be weighed against the increase in cost and weight.

BJL,
There are a number of comments from you dispelling the belief that telephoto lenses designed for the smaller format condense the image circle to a smaller circle with proportionally higher resolution. You've debunked this as being too simplistic. You also stated on page 4 of this thread the following.

Quote
Ray is mostly right that any image you can get with a certain focal length (like 300mm) in one format, you can get about equally as well using the same focal length with a sensor that is larger and yet has the same pixel size, by cropping.

And again on page 1:-
Quote
Using the same focal length as with a smaller sensor and then cropping more means that you use only a portion of the larger sensor of the same size as the smaller sensor.

With the above quotes in mind, I make the following comparison between the Zuiko 300/2.8 and the Canon 300/2.8.

(1) Both lenses are of similar quality.

(2) Both lenses could probably be used on either camera (4/3rds or 35mm) if adaptors were available.

(3) The Zuiko might be a marginally finer lens, but it's also a marginally heavier and more expensive lens.

(4) The current 8mp E-300 or E-500 used with the Zuiko 300/2.8 would deliver higher resolution than the Canon 1Ds2/300mm combination because of the higher pixel density of the E-300, not principally because of any higher resolving capacity of the Zuiko lens.

(5) This temporary advantage of the E-300 for bird watchers will be gradually eroded as pixel density of 35mm sensors increase to the point where AA filters can be dispensed with. Ie., the day Canon introduces a 32MP 35mm sensor is the day 4/3ds becomes irrelevant as a competitor, quality wise, under any circumstances.
Title: the so called minuature formats
Post by: dturina on October 05, 2005, 04:24:05 am
Guys, you are forgetting weight. For 4/3, I can take a 50-200 f/2.8-3.5 and cover the same range as Canon 100-400L. However, the Zuiko is much lighter, sharper and faster, making it a very compact and portable solution. Combined with the 14-54 f/2.8-3.5, as a standard zoom, I would have an excellent two lens combination I can put in a small bag and carry with me all day without having to die under the burden - especially if I take E500 as a lightweight alternative to my E1. Weight is actually as important to me as image quality and ergonomics, because if a system is too heavy, I won't feel inclined to taking it with me for a whole day trip in the national park. It would be too exhausting. Compromises are sometimes good. Highest level of image quality might sometimes be a price I'm willing to pay if it means my back won't hurt the whole day. After all, I'm doing photography for fun, not for money, and it isn't supposed to be hard work. I have that elsewhere.
Title: the so called minuature formats
Post by: Ray on October 05, 2005, 08:20:31 am
Yeah! It's got its advantages. Don't really know why I'm arguing this matter. Probably just trying to get a rise out of BJL  :D .
Title: the so called minuature formats
Post by: BJL on November 11, 2005, 01:52:33 pm
Ray,

   you won't get a rise out of me by comparing lenses of equal focal length with heavy cropping with the larger format: I am comfortable that any differences there favor the smaller format. More to the point, I have no interest in using a smaller format with the same focal length choices as for a larger format. I use my FourThirds body with a 50-200 f/2.8-3.5 lens where I would use a zoom reaching 300mm or 400mm with a larger format, not any 200mm zoom with extra cropping.

At to your idea about the possibility of improving telephoto lens resolution by spending enough money: the same improvements can be applied in smaller formats too.

This fits with one clear general trend, that improvements in resolution, sensitivity, dynamic range and such reduce the visibility of imperfections in all formats, thus reducing the degree of visible image quality differences between two formats, and thus increasing the acceptability of a smaller format and reducing the number of photographers whose image quality needs and wants require a larger format. Mike Johnston has a nice essay on this sort of idea.

Any attempt to use possible future technological improvements in image quality as shifting the balance in favor of larger formats is really getting it backwards. The only way technology can work in that direction is reducing the gap in price, size and weight. But nothing can reduce the focal lengths needed to get any advantage from a larger format, because the format that counts is the size and shape of the image of the desired subject formed on the sensor, irrespective of how much surrounding area is covered with photosites whose output gets cropped away. Any given desired "image format" at a given subject distance determines needed focal length.
Title: the so called minuature formats
Post by: Ray on November 11, 2005, 09:13:44 pm
Quote
Ray,

This fits with one clear general trend, that improvements in resolution, sensitivity, dynamic range and such reduce the visibility of imperfections in all formats, thus reducing the degree of visible image quality differences between two formats, and thus increasing the acceptability of a smaller format and reducing the number of photographers whose image quality needs and wants require a larger format. Mike Johnston has a nice essay on this sort of idea.

BJL,
If you tried using a 5D for a few days and saw first hand just how good images can be at ISO 3200, I think you might change your mind.

It's always struck me that you are very much a theoretician. I get the impression you have opted for the Olymous 4/3rds system primarily because of your interest in and knowledge of  optics. You've been bowled over by the undoubtedly superior optics of the Zuiko lenses but have forgotten that the final result is a 'system' result. If the rest of the system is not at least equal to the fine Zuiko lens, which it apparently isn't, then it matters not how good the lenses are. The quality is essentially wasted.

It's no doubt reasonable to expect that future 4/3rds sensors will improve in quality, but so will every other manufacturers sensors. Henry Ford would not have approved of the Olympus ethos. You don't design a system with one component being streaks ahead of the others.

I think the best thing Olympus could do is make their lenses compatible with Canon APS-C cameras such as the 20D and future upgrades. (I assume the next 20D upgrade will be a 12mp camera). The Zuiko brand could become a premium quality 'third party' lens manufacturer similar to Sigma and Tamron, but better quality and presumably more expensive.

Current Zuiko lenses might also produce better results on a 20D than Canon lenses, but lacking certain automatic functions and, in the case of some lenses, producing a small amount of vignetting.

By the way, I paid just A$4850 for my 5D, considerably less than your prediction of A$6000   .

Cheers!
Title: the so called minuature formats
Post by: BJL on November 14, 2005, 03:49:06 pm
Quote
BJL,
If you tried using a 5D for a few days and saw first hand just how good images can be at ISO 3200, I think you might change your mind.

I get the impression you have opted for the Olymous 4/3rds system primarily because of your interest in and knowledge of  optics. [{POST_SNAPBACK}][/a] (http://index.php?act=findpost&pid=51056\")
I wonder how your opinion would be affected by experience with a Nikon D2X, or even a D200? (Compared at ISO 1600 with one f-stop difference to get equal speed and DOF of course!)

Likely my reaction to any of the three would be "Wow! I see very little reason for me to get a camera and lenses any bigger, heavier or more expensive than this." Unless I ran into ergonomic problems like excessive weight or others not revealed by the spec's, lab. measurements, and sample shots. Because I am not a "maximalist" about image quality, especially not about high shutter speed/low light image quality; I am a balancer of factors, including ergonomics and cost.


My reasons for getting the E-1 and 14-54 f/2.8-3.5 (recently joined by a 50-200 f/2.8-3.5) were actually far simpler and more pragmatic.
In my price range and for my core needs, such as convenient standard and telephoto zoom lenses, it was the best option at that time. Runner up was a Nikon D70 or D100 with 18-70 f/3.5-4/5 DX, but reviews suggested that the optical quality of that lens was not as good as the 14-54. At the time, before EF-S, Canon's best option for my budget was the D60, which did not have a convenient standard zoom (I would have made do with the 17-40 f/4) nor a convenient telephoto zoom to pair with that 17-40. I am still on the same camera (while you have changed twice in the meantime?), so it is a good thing I did not buy the D60 to use with my old Canon gear in the hope of Canon later providing lenses for the D60 adapted to the smaller image circle. A good thing too that I did not decide to stay with film until 24x36mm reached my price range, or I would still be waiting with no relief in sight.

It is not clear what I would choose from today's options, but the Nikon D200 is probably the leading contender, or the E-500 if I were willing to take a stop-gap solution. Given my interest in telephoto reach and macro photography, good sensor resolution in the sense of lp/mm would be a major factor, so my choice would not be a camera like the 5D, even at far less than its current price. With only 3/4's the sensor resolution of the D200 or 2/3's that of the bargain basement E-500, a 5D would require considerably longer telephoto lenses and higher magnification macro gear to get equally detailed images of distant or small subjects, blowing my weight and cost limits.

But I am sure it suits you needs well, as I roughly agree with Phil Askey nuanced final recommendation:
"Highly Recommended ... to anyone looking for the 'purity' of full frame (and a Canon mount) the EOS 5D would be absolutely Highly Recommended. ... For everyone else however it's a hard decision ... only history will tell if the EOS 5D is the start of a full frame revolution or simply the first of a new niche format."
[a href=\"http://www.dpreview.com/reviews/canoneos5d/page32.asp]http://www.dpreview.com/reviews/canoneos5d/page32.asp[/url]

And as an ex-pat I am of course glad to hear that Australian customers are not being gouged as much as they often are on camera prices compared to US prices.

Congratulations!
Title: the so called minuature formats
Post by: kbolin on November 14, 2005, 10:49:10 pm
Wow... this topic seems to go on and on and on.  Why?    

Unless of course you believe equipment is what delivers the final result then let the debate continue.  I for one don't.  It's a tool to deliver ones creative vision.  

Yes I do think about image quality and will buy the 5D early in the new year BUT I look at the image quality, the ergonomics of the camera (something Michael harps about), the economics, and then I buy.  From there I spend my time shooting.

I can use a Canon G5 one day or my 20D the next... depending on what I'm doing and where I'm going.  I often see some fabulous photos my 13 year old son can create using his Canon A95.  Trust me, want to learn more about photography, take your children out for a while and watch them take shots of everything with their eyes wide open.

So while all you are debating and pixel peeping... we are out shooting.

Enjoy.
Title: the so called minuature formats
Post by: Jonathan Wienke on November 15, 2005, 09:05:44 pm
Some of us manage to do a considerable amount of shooting (~50,000 frames/year in my case) while actively participating here. Good gear doesn't guarantee good results, but inferior gear will always compromise the final result to some extent. Pretending otherwise is short-sighted and counterproductive.