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Author Topic: A7 vs other mirrorless options - quality/variety of lenses a real issue?  (Read 30358 times)

barryfitzgerald

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Re: A7 vs other mirrorless options - quality/variety of lenses a real issue?
« Reply #20 on: December 05, 2013, 05:05:17 am »

There's lots of choice in MFT.

I've done extensive testing between MFT, APS-C and "FF" when I owned all three and I decided that the DoF differences between MFT and APS-C just weren't worth worrying about. There's next to no real world difference IMVHO.

DOF is about a stop more than APS-C
I like some of the micro 4/3 lens range it covers a good selection. The problem is I can use my range of 35mm FF lenses on APS-C and whilst 1.5x crop isn't ideal for the wider angle lenses, it's fine for stuff like a 70-200mm. x2 crop is a lot less useful unless you are purely going on reach.
Bottom line is though, you can't get away from the sensor size. I can equal and exceed the performance of the EM-1 with an APS-C camera costing quite a lot less

You could say the same for FF, that the DOF differences are not enough to justify the cost, you get a stop more shallower DOF on full frame.
Depends on what you are looking for. I don't have a problem with the EM-1, it's a nice camera no question. It's just not a £1300 camera
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BJL

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Re: A7 vs other mirrorless options - quality/variety of lenses a real issue?
« Reply #21 on: December 05, 2013, 09:02:20 am »

DOF is about a stop more than APS-C
DOF is about 1/2 stop more in 4/3" format than Canon EF-S, 2/3 stop more than in Sony NEX, Fujifilm X, Nikon DX etc --- if you use the smaller format at the same f-stop, and thus potentially with a smaller, lighter lens.

On the other hand, if you can use lenses of the same effective aperture diameter (entrance pupil size), and so roughly the same size of front elements, which means using the 4/3" format at 1/2 to 2/3 lower f-stop (and thus 1/2 to 2/3 stop lower ISO speed to get the same shutter speed) you end up with about equal DOF, potentially requiring about equal sized lenses. (I ignore the possibility of converting a lens from APS-S to MFT usage with a focal reducer like the ones from Metabones, which preserves DOF at equal aperture settings on the lens, because to me that is a bit of a last resort.)

It largely comes down to how often a particular photographer feels that even the lowest f-stops available in the lens system render too much of the subject in focus.
« Last Edit: December 05, 2013, 09:04:02 am by BJL »
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barryfitzgerald

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Re: A7 vs other mirrorless options - quality/variety of lenses a real issue?
« Reply #22 on: December 05, 2013, 12:31:40 pm »

Pretty good demo here on DOF real world FF v micro 4/3

http://www.mu-43.com/showthread.php?t=25093

I use APS-C 1.5x crop so it would be somewhere around half way between those 2.
I feel that APS-C is a reasonable compromise with decent DOF control, and has products that are relatively well priced.

I can't really see a place for micro 4/3 bar the smaller size
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Vladimirovich

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Re: A7 vs other mirrorless options - quality/variety of lenses a real issue?
« Reply #23 on: December 05, 2013, 01:00:57 pm »

I use APS-C 1.5x crop so it would be somewhere around half way between those 2.

it is not, do not kid yourself... first of all 43/m43 is not 2 crop (the size of the actual imagimg area of the sensor is not 4 times less than FF, but 3.7 times less - and that is only if you believe that part of active pixel area in FF sensor that makes its way into a raw file for an image is indeed 24mmx36mm... which is not) and then you 1.5x crop if you will find the actual sensor specs is less than wikipedia-total size of the die size (try).

PS: example : kodak 43 size sensor (kodak likes the precision in measurments) = http://www.kodak.com/ek/uploadedFiles/Content/Small_Business/Images_Sensor_Solutions/Datasheets%28pdfs%29/KAF-8300LongSpec.pdf

active pixel area = 17.96mm (H) x 13.52mm (V) with 3326 (H) x 2504 (V) active sensels, out of which 3264 x 2448 sensels make it out to the picture (see Olympus cameras w/ that sensor)...

( 17.96mm x 13.52mm  ) * ( ( 3264 x 2448 ) / ( 3326 x 2504 ) ) = 233 mm^2
give FF sensor a favor and assume it really makes the image off 24mm x 36mm, so 24 * 36 / 233 = 3.7... that is not 2 stops... and there is not 1 stop between 43/m43 and APS-C, but way less
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Telecaster

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Re: A7 vs other mirrorless options - quality/variety of lenses a real issue?
« Reply #24 on: December 05, 2013, 01:59:24 pm »

IMO there's room for m43, APS-C and 35mm in the compact mirrorless market. I personally have no regard for one size must fit all arguments. That's fanboy stuff. I also think the E-M1 is worth every penny I paid for it. It's a rock solid picture taker with a high-end feel & performance to match.

I've been enjoying my Y/C-mount Zeiss SLR lenses a lot on m43 cameras via a Metabones SpeedBooster. So much so, in fact, that I wouldn't be averse to getting an A7(r) for them. The real deal-maker, though, would be a high quality Contax/Nikon rangefinder mount adapter for the Sonys with a focusing helical for 50mm lenses. I love my Leitz/Leica/Voigtländer/etc. M & LTM lenses but I adore 1950s-era Zeiss and Nikon RF stuff.

-Dave-
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Isaac

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Re: A7 vs other mirrorless options - quality/variety of lenses a real issue?
« Reply #25 on: December 05, 2013, 02:17:01 pm »

I love my Leitz/Leica/Voigtländer/etc. M & LTM lenses but I adore 1950s-era Zeiss and Nikon RF stuff.

How exciting to have ye olde lenses resurrected!
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barryfitzgerald

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Re: A7 vs other mirrorless options - quality/variety of lenses a real issue?
« Reply #26 on: December 05, 2013, 06:49:46 pm »

it is not, do not kid yourself... first of all 43/m43 is not 2 crop (the size of the actual imagimg area of the sensor is not 4 times less than FF, but 3.7 times less - and that is only if you believe that part of active pixel area in FF sensor that makes its way into a raw file for an image is indeed 24mmx36mm... which is not) and then you 1.5x crop if you will find the actual sensor specs is less than wikipedia-total size of the die size (try).

PS: example : kodak 43 size sensor (kodak likes the precision in measurments) = http://www.kodak.com/ek/uploadedFiles/Content/Small_Business/Images_Sensor_Solutions/Datasheets%28pdfs%29/KAF-8300LongSpec.pdf

active pixel area = 17.96mm (H) x 13.52mm (V) with 3326 (H) x 2504 (V) active sensels, out of which 3264 x 2448 sensels make it out to the picture (see Olympus cameras w/ that sensor)...

( 17.96mm x 13.52mm  ) * ( ( 3264 x 2448 ) / ( 3326 x 2504 ) ) = 233 mm^2
give FF sensor a favor and assume it really makes the image off 24mm x 36mm, so 24 * 36 / 233 = 3.7... that is not 2 stops... and there is not 1 stop between 43/m43 and APS-C, but way less

Leaving aside the technical argument (which I've no idea if it's correct or not)
I've shot extensively on 35mm and APS-C and yes I've used 4/3 cameras too.

You can clearly see the micro 4/3 shot is near to the FF Canon at around f4 when the Olympus is at f1.8, they're close that's near enough to 2 stops. APS-C to full frame is just over a stops difference. It can't really be argued that APS-C doesn't fall "in between" FF and micro 4/3 erm for obvious reasons..because it does!

Now you might not care, you can use faster lenses on micro 4/3 to get there shallower DOF, as you can on APS-C
You could argue that the DOF isn't a big difference micro 4/3 to APS-C, but the reality is somewhat more stark.

DOF is one thing, focal length another. The effects of background compression with longer focal lengths also come into play. A 50mm on full frame, you need a 25mm on micro 4/3, and just under a 35mm on APS-C. That's probably the reason why it's not as easy to get pleasing blur on micro 4/3 even using a 50mm lens on micro 4/3 you have an equivalent field of view of 100mm, and of around 75mm on APS-C. You're effectively moving back with APS-C and micro 4/3 to get the same framing (hence distance to subject DOF)

I'm not arguing you can't get shallow enough DOF on micro 4/3, I'm suggesting that it's not as easy as APS-C and obviously full frame has the creamy blur crown here. Nor do I subscribe to the "Must have blown out background super creamy" for every shot. Like any photo technique it can be overdone and overused.

What I do say is that it's not accurate to state that the DOF differences micro 4/3 to APS-C are insignificant, clearly to some they are significant enough.
Anyway despite some nice lenses, I've yet to see a convincing argument why people should pay near full frame prices for a micro 4/3 body. Sealing or not that's not realistic in the market place.


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BJL

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actual sensor area comparison, in "stops"
« Reply #27 on: December 05, 2013, 07:37:42 pm »

Barry,

    The issue is your claim about the gap between so-called APS-C  and Micro Four Thirds, so why bring 35mm format into it? Unless you want to then revive the ten-year old fallacy that the "APS-C" formats are exactly midway between the other two, so let me debunk that with some numbers.

Based on sensor areas (each factor of two an f-stop), using actual specs of 35.9x24mm for 35mm format, 23.5x15.6 (Nikon D7100) for DX, 22.3x14.9 (Canon 7D) for EF-S, and 17.3x13mm for MFT (Olympus EM-5):
1.37 stops from 35mm to EF-S
1.23 stops from 35mm to DX
0.70 stops from DX to MFT
0.56 stops from EF-S to MFT
and by the way
1.94 stops from 35mm to MFT

Since 1.37 and 1.23 are distinctly larger than 0.70 and 0.56, the so-called APS-C formats are distinctly closer to MFT than to 35mm in size, percentage-wise.
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bcooter

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Re: A7 vs other mirrorless options - quality/variety of lenses a real issue?
« Reply #28 on: December 05, 2013, 08:39:56 pm »

IMO there's room for m43, APS-C and 35mm in the compact mirrorless market. I personally have no regard for one size must fit all arguments. That's fanboy stuff. I also think the E-M1 is worth every penny I paid for it. It's a rock solid picture taker with a high-end feel & performance to match.

I've been enjoying my Y/C-mount Zeiss SLR lenses a lot on m43 cameras via a Metabones SpeedBooster. So much so, in fact, that I wouldn't be averse to getting an A7(r) for them. The real deal-maker, though, would be a high quality Contax/Nikon rangefinder mount adapter for the Sonys with a focusing helical for 50mm lenses. I love my Leitz/Leica/Voigtländer/etc. M & LTM lenses but I adore 1950s-era Zeiss and Nikon RF stuff.

-Dave-

Dave,

I agree with you most of the time and yes there is a place for all formats, but comparing a m43 to a full frame camera with virtually the same features for virtually the same costs (except lenses of course) is hard to justify.

Wouldn't you love to see your older full frame 35mm lenses on a full frame sensor rather than cropped down to 1/2?

IMO

BC
« Last Edit: December 05, 2013, 09:19:03 pm by bcooter »
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Telecaster

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Re: A7 vs other mirrorless options - quality/variety of lenses a real issue?
« Reply #29 on: December 06, 2013, 01:26:31 am »

Wouldn't you love to see your older full frame 35mm lenses on a full frame sensor rather than cropped down to 1/2?

Oh, absolutely. That's why I've got my eye on the Sonys. I have fun with some of the old(er) lenses on m43 cameras but that's a secondary thing. I own the m43 gear for its size, weight and the quality of its native lenses. I do get annoyed by the (IMO) over-reverential attitude often displayed toward the 35mm format online and in print. It stinks of marketeering. But I won't let that stop me from getting any 35mm camera that I decide is worth getting.   :)

-Dave-
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bcooter

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Re: A7 vs other mirrorless options - quality/variety of lenses a real issue?
« Reply #30 on: December 06, 2013, 02:26:13 am »

I do get annoyed by the (IMO) over-reverential attitude often displayed toward the 35mm format online and in print. It stinks of marketeering. But I won't let that stop me from getting any 35mm camera that I decide is worth getting.   :)

-Dave-

Yes, too much emphasis is placed on pure sensor size.  A lot of large sensors don't produce.

My thing about m43 is two fold.  First I have to shoot mostly primes to throw focus with stills and motion,   Even 2.8 doesn't cut it for available light. Second is when I push a file around, especially with lower light or mixed light sources I get a painterly look.

I'm not off m43 though, look forward to the new Panasonic 4k and if I get a break tomorrow will test the em1, before I buy anything new.

For video all of these cameras need the ability to read the whole sensor like a still (I know that's a lot of data) and then down sample later in a computer to cut alaising and moire.

The REDs don't really moire or alaise, at least that i've seen, though the gh3's you have to be careful with. 

I still think though, given the price the A7 and R are well placed for professional stills, casual video actually not much comes close right now.

Thx.

BC
« Last Edit: December 06, 2013, 04:24:55 am by bcooter »
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barryfitzgerald

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Re: actual sensor area comparison, in "stops"
« Reply #31 on: December 06, 2013, 05:04:26 am »

Barry,

    The issue is your claim about the gap between so-called APS-C  and Micro Four Thirds, so why bring 35mm format into it? Unless you want to then revive the ten-year old fallacy that the "APS-C" formats are exactly midway between the other two, so let me debunk that with some numbers.

Based on sensor areas (each factor of two an f-stop), using actual specs of 35.9x24mm for 35mm format, 23.5x15.6 (Nikon D7100) for DX, 22.3x14.9 (Canon 7D) for EF-S, and 17.3x13mm for MFT (Olympus EM-5):
1.37 stops from 35mm to EF-S
1.23 stops from 35mm to DX
0.70 stops from DX to MFT
0.56 stops from EF-S to MFT
and by the way
1.94 stops from 35mm to MFT

Since 1.37 and 1.23 are distinctly larger than 0.70 and 0.56, the so-called APS-C formats are distinctly closer to MFT than to 35mm in size, percentage-wise.

Rather a straw man argument, if I annoyed some by using rough approximations then that's life. You can't argue with what happens in the real world
Bottom line is DOF control is better served on APS-C (and it's noticeable), and the point about focal length works against micro 4/3 more so than the actual DOF numbers illustrate. The reduced compression works against micro 4/3 even with very fast lenses (because of the crop factor and shorter focal lengths)

I don't actually have a problem with micro 4/3, but Olympus are fooling nobody with their "full frame prices for micro 4/3"
Yes micro 4/3 does have good sensors, not quite as good as APS-C, not as good as FF but good enough for many.

It's never an easy sell to push something smaller and not offer a price incentive. At least APS-C is a lot cheaper than full frame, it's also cheaper than micro 4/3 with comparative models. And for many it represents a reasonable compromise v full frame. Micro 4/3 doesn't offer any price advantage or sensor edge, it has less DOF control and it's not hard to see why most makers went with APS-C.

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scooby70

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Re: actual sensor area comparison, in "stops"
« Reply #32 on: December 06, 2013, 08:51:14 am »

...You can't argue with what happens in the real world
Bottom line is DOF control is better served on APS-C (and it's noticeable),...

Yes, the real world... and I do wonder why the argument so often comes down to DoF and by that most people mean thin DoF.

As I mentioned I've rattled off many MFT v APS-C (Canon) v FF test shots and of course many more real world shots and for me personally the difference in ability to produce very limited DoF between MFT and APS-C is minimal and really not worth worrying about. Personaly I find that MFT can deliver thin DoF, if that's trhe aim, simply by using wide apertures and if required altering the framing and / or camera to subject distances. Of course this makes the shot a different shot... it'll be framed differently, but it can still be a nice image real world image :D

Of course there are many instances when using "FF" that you can find yourself fighting aperture, ISO and shutter speed to get adequate DoF and in those situations it may actually be easier to get the shot you want with the DoF you want with a camera with a smaller sensor :D

Anyway, those who can see the advantages of MFT are probably already sold on the idea despite any compromises or limitations and those who don't may never be.
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hjulenissen

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Re: actual sensor area comparison, in "stops"
« Reply #33 on: December 06, 2013, 09:14:52 am »

Anyway, those who can see the advantages of MFT are probably already sold on the idea despite any compromises or limitations and those who don't may never be.
If MFT is "better" than APS-C or FF for a particular application, why stop there? 1" sensors offers even more size reduction.

There seems to be a long-term tendency of photography to move towards smaller sensor size as technology improves (keeping quality more or less constantly "good enough"), yet there seems to be (some) consensus that the potential is larger for larger sensors ("once we hit a technology wall, going larger is the only way to improve"). It will be interesting to see how those two plays out in the future.

-h
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BJL

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Smaller camera plus lens _size_ an important to many photographers
« Reply #34 on: December 06, 2013, 09:25:56 am »

It's never an easy sell to push something smaller and not offer a price incentive.
Barry,

    Will you ever stop ignoring size advantages of a smaller format system offering smaller lenses for many purposes, and instead keep insisting that lower price is the only reason that people might choose a smaller format, even after after all the posts from highly competent and even professional photographers discussing the size factor?

The 1/2 to 2/3 stop difference in DOF wide open that you talk about is part of a simple trade-off with size: the larger formats can achieve that with lenses of the same minimum aperture ratio at focal lengths about 5/4 to 4/3 greater, and so with maximum effective aperture diameter greater by the same factor, and consequent increase in size, weight and typically in cost (glass volume goes up by the cube of those linear scale factors.) The comparison is currently complicated by the fact that the slightly larger format mirrorless system often lack those lenses of equal minimum aperture ratio at equal angular FOV.

Also, comparing the most expensive, high spec body in one format to the cheapest offering in another is, in ypur words, a straw man, perpetuating the digital era myth that sensor performance is the only factor in camera choice. Let me remind you that film cameras in the same 35mm format came at a very wide variety of prices, based on features unrelated to sensors, since they could all be loaded with the same "sensors". With the more expensive of the Olympus MFT bodies, state-of-the-art in-body stabilization and sensor-based AF come to mind.

To put it another way, the vast majority of MFT and "APC-C" format mirrorless cameras are not in price competition with 35mm format cameras.
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BJL

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Re: actual sensor area comparison, in "stops"
« Reply #35 on: December 06, 2013, 09:41:04 am »

If MFT is "better" than APS-C or FF for a particular application, why stop there? 1" sensors offers even more size reduction.

For some people, maybe many people, 1" format could indeed offer a better balance of size vs performance, especially as technology improves --- if some company puts more effort into developing a good broad lens system for that format than Nikon has so far. More and more, I see lens systems as the slower changing part of a system that leads to more persistent competitive advantages and disadvantages, and so better predictors of future competitive advantage than the rapidly changing electronic features such as "who has the best on-sensor AF this month".

But we should beware slippery slope arguments like "if a somewhat bigger/smaller is better, then an even bigger/smaller is even better, so in the end we will use use either the tiniest camera-phone sensors or FULL FRAME medium format." My lower size limit for a system camera will probably be set by whether the low light handling needs of the brightest zoom lenses viable for that format and within my budget is good enough. For that judgement, I suspect that we are getting close to the limits for sensitivity improvement, with photon shot noise already dominant in most situations (at least in non-Canon CMOS sensors!) so that my lower format size limit will not move down much more than it already has.
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Vladimirovich

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Re: A7 vs other mirrorless options - quality/variety of lenses a real issue?
« Reply #36 on: December 06, 2013, 10:22:32 am »

You can clearly see the micro 4/3 shot is near to the FF Canon at around f4 when the Olympus is at f1.8,
I am sorry, I can't clearly see 4.0 vs 1.8 or 3.5 vs 2.0... but if you can illustrate may be with both pairs ?
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Vladimirovich

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Re: actual sensor area comparison, in "stops"
« Reply #37 on: December 06, 2013, 10:27:22 am »

For some people, maybe many people, 1" format could indeed offer a better balance of size vs performance, especially as technology improves
and PDAF on sensor with Nikon 1 is the best one around mirrorless cameras (in a good light), so if you want to use a small, mirrorless camera in a daylight to shoot moving targets Nikon 1 is the system to use, not m43/NEX/Fuji/Samsung or whatever
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hjulenissen

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Re: actual sensor area comparison, in "stops"
« Reply #38 on: December 06, 2013, 12:32:50 pm »

But we should beware slippery slope arguments like "if a somewhat bigger/smaller is better, then an even bigger/smaller is even better, so in the end we will use use either the tiniest camera-phone sensors ...
If the argument is that "the smaller the better", then indeed, the tiniest camera-phone sensors should be the way to go.

This only indicates that such an argument is false, or incomplete. You might say that I am argueing against strawmen here, but I am trying to encourage people to avoid short politician-like slogans ("m43 rulez"), and rather attach some sober conditions to their statements.

There seems to be some truth in that there are certain advantages for going smaller (size/weight/price), and other advantages for going large (more room for manufacture tolerances, larger equivalent apertures, higher total number of megapixels). This indicate to me that there is probably some application-dependant sweet-spot.

And all of the theoretical/physical speculation is of little value for camera buyers unless one also factor in economic and availability factors. 36x24mm have some lens catalogs that have little to do with the sensor size, and a lot to do with the number/type of FF cameras sold for decades. If you want a 5x macro, an assortement of top-notch tilt/shifts etc, 2x crop may be at a disadvantage until equivalents of those lenses are made for that format (I have no reason to believe that it cannot be done).

-h
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BJL

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format sweet spot --- for each particular user and pattern of usage
« Reply #39 on: December 06, 2013, 01:49:48 pm »

If the argument is that "the smaller the better", then indeed, the tiniest camera-phone sensors should be the way to go.

This only indicates that such an argument is false, or incomplete. You might say that I am argueing against strawmen here, but I am trying to encourage people to avoid short politician-like slogans ("m43 rulez"), and rather attach some sober conditions to their statements.

There seems to be some truth in that there are certain advantages for going smaller (size/weight/price), and other advantages for going large (more room for manufacture tolerances, larger equivalent apertures, higher total number of megapixels). This indicate to me that there is probably some application-dependant sweet-spot.
With Scooby70 and I at least yes, I would say that you are arguing against a strawman, though it might still be worth saying to some others who do offer such simplistic "extremist" arguments. For example, Scooby70 has clearly stated the balancing consideration that is likely to rule out some formats as too small, and so lead to MFT being in his sweet spot:
Quote
Personally I find that MFT can deliver thin DoF ...
That is also roughly my thinking; I rarely if ever crave shallower DOF than I can get with the faster of my lenses (f/2.8-3.5 and f/2.8-4 zooms), and even though I would occasionally like more speed, the combination of big, bright zoom lenses and a larger format body that would deliver significantly better high shutter speed/low-light handling costs and weighs more than I deem worthwhile. On the other side, the lenses offered so far for Nikon's 1" format system offer far less speed (and far less DOF flexibility), with all the zooms being f/5.6 at the long end, and Pentax Q ids even further from satisfying my needs.

Clearly this at most puts MFT in my current sweet spot; I am not arguing that it fits anyone else's sweet spot, or that it will fit mine forever.
« Last Edit: December 06, 2013, 01:51:37 pm by BJL »
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