Luminous Landscape Forum
Equipment & Techniques => Medium Format / Film / Digital Backs – and Large Sensor Photography => Topic started by: smoody on January 05, 2011, 05:43:39 pm
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I'm on my second 645D. I am about to return it or exchange it for a third, but wanted to get some consensus on what I'm seeing. Both of my 645Ds paired with the new 55mm lenses exhibited similar softness approaching the edge. Here are the facts:
- When shooting city landscapes (my standard real-world focused-as-infinity resolution test), I noticed that anything left or right of center was very soft.
- To produce something close to an apples-to-apples comparison, I took two 645D shots. The clear one, as you might expect, is from the center of the image. After taking the clear one, I panned my camera/tripod head to the right so that the exact same buildings were now on the left-side of the image -- not the extreme left edge, just the left side.
- Both shots were taken without window glass between the 645D and the scene being shot. Both exposed at f/5.6, 1/750th of a second, using the new 55mm, tripod mounted, manually focused at same point (infinity), pre-shot mirror lockup via 2 second timer, captured as DNGs and converted using ACR (but out-of-camera JPEGS looked essentially the same minus difference to color balance). Both shots are completely in-focus at the center of the frame. Both are 100% crops. Both were sharpened -- perhaps to fault -- to see how much detail I can pull out of the crops.
Without further delay...
The center crop:
(http://10101010.net/645DCenter.png)
The same buildings, but on the left side of the image:
(http://10101010.net/645DLeft.png)
The edge seems very smeared to me. I emailed the images to Pentax tech support and they said that the cannot say if the softness I am seeing is within tolerances and pretty much refuse to look at anything other than a shot of a test chart, which I understand, but a test chart can't detect any defects shot at infinity. I know there are very few people with 645Ds out there right now, but...
- For those with 645Ds, are you seeing the same thing? It is only very noticeable to me focused at infinity. Shots taken on the street seem okay, but, of course, depth of field comes into play in that case.
- For those with other medium format systems, is this fairly typical of near-edge sharpness at near-optimal f/stop with your body/back/lenses?
I'd normally assume that I received a bad component, but as this is my second 645D, I'm wondering if it's a limitation of the optics and/or the 645D's ability to resolve properly across the entire sensor at infinity.
For completely useless grins, here is the same shot that was blurry with the 645D (from left-side of image) taken with a Leica M9 in combination with Leica's cheapest lens, the 50mm Summarit (which, coincidentally, costs as much as the Pentax 55mm -- at least at the time I bought it) -- same f/stop, shutter speed, etc.
(http://10101010.net/LeicaLeft.png)
Thanks,
Scott
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Hi,
Sorry to say, Lloyd Chambers tested the Pentax 645D and albeit he was very positive to the camera he didn't find satisfaction in the 55/2.8. He tested two samples and neither impressed in the edges/corners. Most other lenses he tested were good.
http://www.diglloyd.com/prem/prot/DAP/Pentax645D/compare-Canon5DM2-55mm.html
"Diglloyd" is a pay site, but I'd suggest that the money is well invested.
Best regards
Erik
I'm on my second 645D. I am about to return it or exchange it for a third, but wanted to get some consensus on what I'm seeing. Both of my 645Ds paired with the new 55mm lenses exhibited similar softness approaching the edge. Here are the facts:
- When shooting city landscapes (my standard real-world focused-as-infinity resolution test), I noticed that anything left or right of center was very soft.
- To produce something close to an apples-to-apples comparison, I took two 645D shots. The clear one, as you might expect, is from the center of the image. After taking the clear one, I panned my camera/tripod head to the right so that the exact same buildings were now on the left-side of the image -- not the extreme left edge, just the left side.
- Both shots were taken without window glass between the 645D and the scene being shot. Both exposed at f/5.6, 1/750th of a second, using the new 55mm, tripod mounted, manually focused at same point (infinity), pre-shot mirror lockup via 2 second timer, captured as DNGs and converted using ACR (but out-of-camera JPEGS looked essentially the same minus difference to color balance). Both shots are completely in-focus at the center of the frame. Both are 100% crops. Both were sharpened -- perhaps to fault -- to see how much detail I can pull out of the crops.
Without further delay...
The center crop:
(http://10101010.net/645DCenter.png)
The same buildings, but on the left side of the image:
(http://10101010.net/645DLeft.png)
The edge seems very smeared to me. I emailed the images to Pentax tech support and they said that the cannot say if the softness I am seeing is within tolerances and pretty much refuse to look at anything other than a shot of a test chart, which I understand, but a test chart can't detect any defects shot at infinity. I know there are very few people with 645Ds out there right now, but...
- For those with 645Ds, are you seeing the same thing? It is only very noticeable to me focused at infinity. Shots taken on the street seem okay, but, of course, depth of field comes into play in that case.
- For those with other medium format systems, is this fairly typical of near-edge sharpness at near-optimal f/stop with your body/back/lenses?
I'd normally assume that I received a bad component, but as this is my second 645D, I'm wondering if it's a limitation of the optics and/or the 645D's ability to resolve properly across the entire sensor at infinity.
For completely useless grins, here is the same shot that was blurry with the 645D (from left-side of image) taken with a Leica M9 in combination with Leica's cheapest lens, the 50mm Summarit (which, coincidentally, costs as much as the Pentax 55mm -- at least at the time I bought it) -- same f/stop, shutter speed, etc.
(http://10101010.net/LeicaLeft.png)
Thanks,
Scott
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I'm on my second 645D...
I do not own the camera but have seen much better shots/crops, also with the 55mm lens. And even if I would not have seen any samples it's pretty clear that there is something wrong.
I think either the lens is totally decentered or the sensor mounting is out of perpendicualr alignement. Actually it looks like "swing" on the sensor... but if there was the same issue on the first body with the exact same lens (?) it's probably the lens.
And you are right... sensor misalignement or a decentered lens are better checked at infinity...
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Hi,
Have you noticed the amount of Moiré and aliasing on the sharp Pentax 55/2.8 shot and also on the Leica? The sharpness is impressive but aliasing is the price you pay.
Best regards
Erik
I'm on my second 645D. I am about to return it or exchange it for a third, but wanted to get some consensus on what I'm seeing. Both of my 645Ds paired with the new 55mm lenses exhibited similar softness approaching the edge. Here are the facts:
- When shooting city landscapes (my standard real-world focused-as-infinity resolution test), I noticed that anything left or right of center was very soft.
- To produce something close to an apples-to-apples comparison, I took two 645D shots. The clear one, as you might expect, is from the center of the image. After taking the clear one, I panned my camera/tripod head to the right so that the exact same buildings were now on the left-side of the image -- not the extreme left edge, just the left side.
- Both shots were taken without window glass between the 645D and the scene being shot. Both exposed at f/5.6, 1/750th of a second, using the new 55mm, tripod mounted, manually focused at same point (infinity), pre-shot mirror lockup via 2 second timer, captured as DNGs and converted using ACR (but out-of-camera JPEGS looked essentially the same minus difference to color balance). Both shots are completely in-focus at the center of the frame. Both are 100% crops. Both were sharpened -- perhaps to fault -- to see how much detail I can pull out of the crops.
Without further delay...
The center crop:
(http://10101010.net/645DCenter.png)
The same buildings, but on the left side of the image:
(http://10101010.net/645DLeft.png)
The edge seems very smeared to me. I emailed the images to Pentax tech support and they said that the cannot say if the softness I am seeing is within tolerances and pretty much refuse to look at anything other than a shot of a test chart, which I understand, but a test chart can't detect any defects shot at infinity. I know there are very few people with 645Ds out there right now, but...
- For those with 645Ds, are you seeing the same thing? It is only very noticeable to me focused at infinity. Shots taken on the street seem okay, but, of course, depth of field comes into play in that case.
- For those with other medium format systems, is this fairly typical of near-edge sharpness at near-optimal f/stop with your body/back/lenses?
I'd normally assume that I received a bad component, but as this is my second 645D, I'm wondering if it's a limitation of the optics and/or the 645D's ability to resolve properly across the entire sensor at infinity.
For completely useless grins, here is the same shot that was blurry with the 645D (from left-side of image) taken with a Leica M9 in combination with Leica's cheapest lens, the 50mm Summarit (which, coincidentally, costs as much as the Pentax 55mm -- at least at the time I bought it) -- same f/stop, shutter speed, etc.
(http://10101010.net/LeicaLeft.png)
Thanks,
Scott
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Have you noticed the amount of Moiré and aliasing on the sharp Pentax 55/2.8 shot and also on the Leica? The sharpness is impressive but aliasing is the price you pay.
that is one very helpful comment to sort out the issues.
And it sure required another full quote of the OP.
???
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This totally looks like a lens issue, doesn't it?
The Pentax 55mm f2.8 appears to be an average performer at best, but my question would be at what aperture you shot?
I would expect f8 to be better than this.
Regardless, you should try to other lenses like the 75mm of 120 f4 macro known to be excellent (at least in their non AF versions).
Cheers,
Bernard
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Yeah it looks like a lens issue to me for sure. Doesn't look great either!
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Bernard,
Both exposed at f/5.6, 1/750th of a second, using the new 55mm, tripod mounted, manually focused at same point (infinity), ...
Scott, I don't think your expectations are unreasonable. Your technique seems fine. I agree with the others on this thread that the lens doesn't seem to be cutting it. It might be just your copy or it might be the lens design itself. Do you have other focal lengths to try?
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Lloyd's findings in short (DAP is subscription based but a lot conclusions are in the blogs like this):
http://diglloyd.com/diglloyd/2011-01-blog.html#blog20100104Pentax120f4
The new 55mm and 45mm FA are bad out of the center 1/2 (55mm) and 2/3 (45mm) area.
The 75mm and 200mm are very good at least (hard to focus).
The 45-85mm zoom is excellent, and way outperforms the 45 and 55 primes. (no surprise -- after careful testing I sold all my Pentax 67 prime lenses in the range of the two zooms.)
The 120mm macro is outstanding, razor sharp corner to corner even wide open at f/4.
He is going to test more (150mm, 80-160mm zoom, and some Pentax 67 lenses through the adapters, at least).
Else where on the web you can find sample images from the 35mm and the 33-55mm zoom. They look fine and 16-9.net tested and found the Pentax 645 35mm the best wide angle in MF field. Now lacking are sample images and reviews of the 55-110 and the 150-300 zooms, and the long (300mm ED IF, 400mm ED IF, and 600mm ED IF) optics.
Pentax released a new firmware (V1.0.1) for the 645D to support SDXC cards, and promised firmware changes in the future for tethered shooting as well as new lenses including a new wide angle, rumored a 25mm/f4.
About the 67 adapter on 645 and 645D -- you can use the 67 lenses exactly as the 645 MF (A) lenses:
“Pentax has two medium format camera lines, the Pentax 67 and the Pentax 645. Unique among camera makers,
Pentax has designed the systems so that the lenses from the 6X7 camera can also be used on the 645 body. They
manufacture an adaptor for this that retains autodiaphram and open-aperture metering capability. Put it on a 645
body and you can use all your 67 lenses pretty much as normal. (Contax allows their 645 lenses to be used on the
N series 35mm cameras. Pentax has an adaptor that allows medium format to 35mm as well, but in this case
autodiaphram is lost.)”
You can also buy small gadgets like this:
Pentax O-RC1 Remote Control
"A simple item that didn’t come with the 645D camera was a remote control. The Pentax O-RC1 is a simple device that allows you to fire the shutter without pushing the shutter release button. This is great for self portraits and family photos as it avoids the self-timer dash. More importantly for me, it means I can eliminate any micro wobble that may occur when pressing the shutter release button on a tripod mounted camera. As a bonus the remote control is waterproof, which in rain soaked Okinawa is probably a good idea.
The remote control also works with other 2010 Pentax cameras including the Optio W90."
Lloyd's DAP and other detailed paid references (such as digital infrared) are worth the subscription cost to my opinion.
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Hi,
You are absolutely correct!
On the other hand I posted a comment on Diglloyd's findings with two other samples on the same lens, after actually rereading his review. They were pretty much similar.
I couldn't resist commenting on the Moiré, because it's a very good example of it showing up but also because I have observed a lot of Moiré when I was Pixel peeping the few raw files that have been published from MF cameras. Nothing unexpected, it's the price of working without an AA filter. It also indicates that the lens outresolves the sensor, even if the correct terminology may be that it has high MTF at Nyquist limit.
By the way, most of the lenses Diglloyd has tested on the P645D are fine. He found the 55/2.8 and his sample of the 45/2.8 lacking. But he found 45-85, 75/2.8 and 120/4 very good. The 200/4 (non AF) was very difficult to focus manually.
Best regards
Erik
that is one very helpful comment to sort out the issues.
And it sure required another full quote of the OP.
???
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What seems quite extraordinary to me is that Pentax are shipping their flagship camera with what is quite evidently a sub-standard optic. If any of my 'Blad lenses were as poor as that I would weep. Surely the camera should be offered with a decent quality standard prime (whatever that would be - the 75mm f2.8?). It is even more puzzling because we know that Pentax can produce some really fine lenses.
John
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What seems quite extraordinary to me is that Pentax are shipping their flagship camera with what is quite evidently a sub-standard optic.
It can be targeted to portrait shooting since the center sharpness is very high (told from the amount of moiré), on the par of the Leicas (S2). The performance also improves when focused to nearby. The 75mm/2.8 is good. On the other hand Lloyd have showed at least some of the Hasselblad lenses are far worse than the 40-60MP sensor demands. On the film days I always challenged Hasselblad shooters on the light tables through a 22x loupe, and my Pentax chromes always won.
All the existing Pentax 67 lenses should perform flawlessly all the way to the corners, an advantage most other systems could not match. I posted a 100% resolution target shot off a 5DMKII to show even the Pentax zooms can outperform the best 35mm lenses widely open.
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It can be targeted to portrait shooting since the center sharpness is very high (told from the amount of moiré), on the par of the Leicas (S2).
Why on earth would you choose to shoot portraits with a 55mm? Surely its natural role is for landscape and architecture, just the subjects which will suffer from poor sharpness across the frame.
John
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Why on earth would you choose to shoot portraits with a 55mm? Surely its natural role is for landscape and architecture, just the subjects which will suffer from poor sharpness across the frame.
John
Exactly my thoughts John, but we are from a different generation, I suspect. To moderns, distortion is cool.
As for 6x7 format lenses beating 35mm format lenses, that's into science fiction. The whole problem associated with people making the step up from 35mm cameras to medium format (top quality in both cases) was that they assumed that they were multiplying 35mm quality by the film size factor, when the truth is that 35mm formats are such superlative peformers precisely because the designers only have to cover a small area with the 35mm format, and simply can't achieve the same degree of quality over the larger area mf presents... The only real advantage from mf has always been that of tonality. Period.
Rob C
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that is one very helpful comment to sort out the issues.
And it sure required another full quote of the OP.
???
That's the way this forum works: We use their shots to help inform us generally.
Edmund
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The only real advantage from mf has always been that of tonality. Period.
Tonality have always been a vague term to me. Is it something that one can read out of dxo measurements, or something that can be clearly pointed to in a side-by-side comparision of images from cameras that "good" tonality vs "bad" tonality?
-h
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+1
Tonality have always been a vague term to me. Is it something that one can read out of dxo measurements, or something that can be clearly pointed to in a side-by-side comparision of images from cameras that "good" tonality vs "bad" tonality?
-h
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Tonality have always been a vague term to me. Is it something that one can read out of dxo measurements, or something that can be clearly pointed to in a side-by-side comparision of images from cameras that "good" tonality vs "bad" tonality?
-h
I've always found the difference in tonality between 35mm and MFD to be very obvious once you start working with the images in post production. My old P25 still outperforms my 5d mkII by far in this regard. But I guess it's mainly in heavy duty post like fashion and advertising you'll notice this the most.
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I couldn't resist commenting on the Moiré, because it's a very good example of it showing up but also because I have observed a lot of Moiré when I was Pixel peeping the few raw files that have been published from MF cameras. Nothing unexpected, it's the price of working without an AA filter.
Why couldn't you resist? Is it some kind of sports for you to point out issues with MFD?
Seems so...
The OP referred to a lens or sensor issue... not to the ease of use of a non AA filtered vs. an AA filtered camera.
if you look at the first of the 2 samples available here http://www.leaf-photography.com/products_aptus212r.asp you will find that moiré isn't an issue.
The shot was taken with one of the sharpest lenses available and the motif is extremely prone to show moiré.
So obviously it depends on the pattern-size of the subject and the pixel pitch of the sensor (the Apt.12's pixel pitch is 5.2microns).
I do not negate the issue of moiré with non AA filtered sensors, not at all (why would I... I have to deal with it quite often).
But unless you shoot fabrics (or similar subjects) it's mostly an easy fix. In those landscape or cityscape shots it's often not an issue at all (depends on the actual motif, of course).
Moiré can also totally ruin a shot... in this case you have to either stop down (to f22 or so ... at the price of less sharpness... and maybe also at the price of more DOF than you actually wanted to achieve) ... or use an appropriate camera.
I think generalized statements require some kind of substantiated experience with the subject the respective statement refers to.
Looking at some arbitrary samples available online won't do.
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Hmmm. Well anyhow, to return to the original topic from the OP -
* No, your expectations are not at all unreasonable.
* There is probably absolutely nothing wrong with your camera (or the one before). It is the 55mm lens which seems to be the problem.
So request that your dealer swap the 55mm for a better lens.
John
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Detail.
To resort to the anecdotal, derided in these pages some time earlier, I look at my own experience. Nikon and Hasselblad gave much the same detail in the circumstances in which I found myself working. The general max. size I ever needed for most things printed perfectly well onto 10"x12" paper, from either system (as seems to be true today with digital prints on A3+ from either type of digital camera). For larger work, such as full- or half-page press ads and fashion show and shop displays on 40"x60" paper, either camera was as useful because the working distance - the viewing distance - was relatively great and detail was resolved much the same way. What was rather different, though, was the tonality.
Tonality.
I assume the dxo question about it was posted in jest, but if not, it displays one of the current problems besetting photography today: snappers abrogating experience for the illusion of mechanically/electronically measured values which you can't always get; I wonder about the dxo rating of Caravaggio or even dear old Vinnie van G - can't be measured? can't be valid, then. Interesting take on life, my friend.
The definition of tonality that I grew up with was fairly simple: it's the quality of the visible and uninterrupted continuum of a grey or a colour that is not broken down by the failures of the medium upon which it is created. Tonality and grain are the usual suspects here, and both are the unavoidable factors that produce the quality of tonality as well as its failure. Judgement of tonality depends on a trained, experienced eye that understands what's possible and where it is either maintained or lost. That said, even the untrained eye should be able instantly to detect the differences in tonality in two similar sized prints from two very differently sized negatives or positives. The trick, of course, is having the skill to make judgement calls when confronted with a single print and no comparator.
Rob C
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The level of detail needed for a given task and the level of detail available are quite different animals.
If billboards are your thing then viewing distance is applicable, rather less so for anything purporting to be fine art anything.
Quite so, and that's where user discretion has to rule. To spend or not to spend, is one system 'better' for me than another? Which brings the circle back to the point and question of whether using mf at all is realistic for some shooters, not just economically but from the working perspective too. It's much the same as the old one about running a Ferrari in Malta.
Rob C
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Hi,
The problem it seems is that there are many samples of the 55/2.8 which don't impress testers, specially in corners and edges, so it may not be a sample problem with your lens but a more specific problem with the 55/2.8. It seems that there are many other Pentax lenses that work fine, but possibly lack AF and definitively ultrasonic drive.
Best regards
Erik
Hmmm. Well anyhow, to return to the original topic from the OP -
* No, your expectations are not at all unreasonable.
* There is probably absolutely nothing wrong with your camera (or the one before). It is the 55mm lens which seems to be the problem.
So request that your dealer swap the 55mm for a better lens.
John
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Tonality.
I assume the dxo question about it was posted in jest, but if not, it displays one of the current problems besetting photography today: snappers abrogating experience for the illusion of mechanically/electronically measured values which you can't always get; I wonder about the dxo rating of Caravaggio or even dear old Vinnie van G - can't be measured? can't be valid, then. Interesting take on life, my friend.
The definition of tonality that I grew up with was fairly simple: it's the quality of the visible and uninterrupted continuum of a grey or a colour that is not broken down by the failures of the medium upon which it is created. Tonality and grain are the usual suspects here, and both are the unavoidable factors that produce the quality of tonality as well as its failure. Judgement of tonality depends on a trained, experienced eye that understands what's possible and where it is either maintained or lost. That said, even the untrained eye should be able instantly to detect the differences in tonality in two similar sized prints from two very differently sized negatives or positives. The trick, of course, is having the skill to make judgement calls when confronted with a single print and no comparator.
Rob C
I mentioned DXO and fair side-by-sides because they are both "fair" within their respective limits. Measurements are not inherently "bad", but one should know what they measure, and have skill to interpret (extrapolate) them. That is not always the case, and I suspect that is why some peopleare so negative towards measurements. I find comparision to measurements of painters to be falsely constructed for this discussion, and dont see
any point in discussing them further.
Statements about trained experienced eye, skill to make judgement call etc may well be correct, but they also open to all kinds of "emperrors clothes" issues.
If there are real, visible, repeatable differences in what you call tonality, surely someone must by now have made fair comparisions between a 5Dmk2 and a 645D, tweaking raw developer settings for visual similarity (documenting what they did), and showing us clearly the benefit of MF?
-h
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I mentioned DXO and fair side-by-sides because they are both "fair" within their respective limits. Measurements are not inherently "bad", but one should know what they measure, and have skill to interpret (extrapolate) them. That is not always the case, and I suspect that is why some peopleare so negative towards measurements. I find comparision to measurements of painters to be falsely constructed for this discussion, and dont see
any point in discussing them further.Statements about trained experienced eye, skill to make judgement call etc may well be correct, but they also open to all kinds of "emperrors clothes" issues.
If there are real, visible, repeatable differences in what you call tonality, surely someone must by now have made fair comparisions between a 5Dmk2 and a 645D, tweaking raw developer settings for visual similarity (documenting what they did), and showing us clearly the benefit of MF?
-h
Exactly my points:
a. why would you accept something you can't dispute if it spoils your argument;
b. measurements are sooo scientific, but art and its appreciation never can be, and photographic tonality no less so. I can only conclude that if you, personally, can't distinguish tonality as either good or poor, then you have little photographic experience which indeed renders this correspondence futile.
But hell, it's a new year, let's not all get bogged down in more verbal trash! I, for one, shall try not to add to what's already choking the word.
Rob C
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a. why would you accept something you can't dispute if it spoils your argument;
I am not sure what you are referring to, but you brought painters into the discussion. I think that the quality of painted art cannot be measured, so do you, so there seems to be nothing to discuss.
If you claim is that if the quality of painted art cannot be measured, then the quality of photographic equipment cannot be measured, then I disagree as those are two very different things.
b. measurements are sooo scientific, but art and its appreciation never can be, and photographic tonality no less so.
I am sure that there are really good photographers out there that dont read dxo measurements, but dont know what medium format is either. The point is: if you state that medium format makes better art than other formats, then you are allready stepping out of the art-making and into technical explanations.
Making bold statements about how the world works (something like "MF has much better tonality than anything else"), then hiding behind the "I am making art, so anyone questioning my conclusions are electronic nerds"-argument does little to advance my or your understanding, or the state of the art.
I can only conclude that if you, personally, can't distinguish tonality as either good or poor, then you have little photographic experience which indeed renders this correspondence futile.
I make no claims about my photographic experience, but the sentence above tells me more about you than it does about tonality. If it cannot be seen, cannot be smelled, cannot be heard, cannot be explained, then it probably only exists in the head of the true believers. I have no intention of becoming a religious person, I joined this forum to improve my photography skills and understanding of my equipment, and this is not helping.
-h
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Making bold statements about how the world works (something like "MF has much better tonality than anything else"), then hiding behind the "I am making art, so anyone questioning my conclusions are electronic nerds"-argument does little to advance my or your understanding, or the state of the art.I make no claims about my photographic experience, but the sentence above tells me more about you than it does about tonality. If it cannot be seen, cannot be smelled, cannot be heard, cannot be explained, then it probably only exists in the head of the true believers. I have no intention of becoming a religious person, I joined this forum to improve my photography skills and understanding of my equipment, and this is not helping.
-h
Just because YOU can't see, smell, hear or explain something does not mean it does not exist. I'm sure that I can't tell the difference between an "OK" and a great violin, but Yitzhak Perlman can. I SHOULD be able to measure the thickness of the wood, the vibration qualities and such and completely understand a violin and tell Mr. Perlman which one will be the best instrument for him, but I can't.
Things like what Rob said will not help you understand the technical aspects of you equipment, but if you think for a moment it wont improve your photography skills, I'm sorry to tell you that you are incorrect.
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Smoody:
I have a 645D, but not the new 55mm. I am in the process of testing the 17 645/67 lenses I own and have not seen anything remotely as bad as you've posted, in fact, the older lenses are doing quite well. So unless you've drawn two bad bodies, it appears to be a lens issue I've posted some results representative of what I'm seeing here where I am comparing the 645D to 645N film scans:
http://tsjanik.blogspot.com/2011/01/blog-post_9035.html
The first image is a crop from the 645D, no post processing (120mm macro); the second is the full image taken on Astia; the third is a 645N crop with PP (detail has been lost in the jpeg conversion).
The old 55mm is quite good and inexpensive, but manual focus.
Tom
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Just because YOU can't see, smell, hear or explain something does not mean it does not exist. I'm sure that I can't tell the difference between an "OK" and a great violin, but Yitzhak Perlman can. I SHOULD be able to measure the thickness of the wood, the vibration qualities and such and completely understand a violin and tell Mr. Perlman which one will be the best instrument for him, but I can't.
My point is that if mr Perlman cannot distinguish between an OK and a great violin blindfolded, then he is probably fooling himself subconsciously if he claims that one is "better" than the other. If he cannot produce two recordings blindfolded of the two where he himself or others can pick out which is which, then choice of violin does not seem to matter wrg acoustical properties (as long as he is going to do sighted concerts it may still matter because having an expensive one may make him feel better and thus do a better performance, but that is probably not the explanation that was given in the first place).
I started out with a simple question: is it possible to measure tonality using DXO, or to show us the effect in a fair side-by-side set of images. Neither of you have answered this in a sensible manner, instead you have attacked measurements in general, and focused on my photography skills (or lack thereof). I am sad to say that that kind of reaction does not make me trust your conclusions or statements.
Things like what Rob said will not help you understand the technical aspects of you equipment, but if you think for a moment it wont improve your photography skills, I'm sorry to tell you that you are incorrect
I am sorry, but this is nonsense. Arguments of the tonality of MF cameras wont make me take better pictures. If you think that, then we are indeed living on very different planets. Going out taking pictures may make me a better photograph, studying the work of others may make me a better photograph, getting critizism for my work may make me a better photograph. Thinking about composition, what is aesthetically pleasing, what draws my attention to a scene in the first place may make me a better photograph. But nit-picking about one of the supposed benefits of an expensive camera technical feature (tonality vs Sensor-size) that no-one are willing to show examples of, is almost certainly not making me a better photograph.
-h
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I think that a great deal of this endless wrangling over MF versus 35mm completely misses some very important points.
If you take a photograph of a well-lit, perfectly framed subject in ideal conditions, the difference between an MF camera and something like a 5D2 or D3X in the final print will probably be utterly minimal. You would have to enlarge the shot to 36x24 or something to see any MF advantage. However, where the MF has a huge advantage and will save your arse is when things go wrong, as (in my case at least) they do so often. If the subject is a difficult one, with either too much contrast, or too little, and needs lots of post-shoot manipulation, you will find that you can push and pull the MF file around in LR or ACR or whatever far more than the 35mm one. Those big MF files will take a lot of messing with, and still look good. The huge other advantage of MF is when your framing was, shall we say, less than optimal. I can easily crop down to just 25% of the original image area and it still looks just fine printed to A3. In fact, sometimes I can get two good pictures (and different) out of one MF frame.
So for someone like me, who so often totally fouls up the shot, MF is absolutely the bee's knees :D And I'm not too proud to admit it.
John
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Tonality have always been a vague term to me. Is it something that one can read out of dxo measurements, or something that can be clearly pointed to in a side-by-side comparision of images from cameras that "good" tonality vs "bad" tonality?
+1
If there are real, visible, repeatable differences in what you call tonality, surely someone must by now have made fair comparisions between a 5Dmk2 and a 645D, tweaking raw developer settings for visual similarity (documenting what they did), and showing us clearly the benefit of MF?
Here are RAW-file comparisions (I think Canon 1DsIII / P65+ & D700 / P65+):
http://www.phaseone.com/de-DE/Downloads/Sample-images.aspx
You can play around with the files.
You need Capture One Pro to do so… there's a free 30day trial on the website.
Note that some images already contain settings (i.e. not "preset" settings; they are adjusted for certain purposes. There was an article these files refer to, hence the adjustments applied to the captures. But I don't know whether or not the article is still available somewhere... )
Also note that in terms of tonality a "comparision" of course is seriously limited by the quality, gamut and linearity of your monitor.
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Why on earth would you choose to shoot portraits with a 55mm? Surely its natural role is for landscape and architecture, just the subjects which will suffer from poor sharpness across the frame.
John
But bear in mind the crop factor: 55mm on the 645D gives the same diagonal FOV as an 80mm lens on a 6x6cm film camera...and a hell of a lot of portraits were shot down the years with 80mm standard lenses on all those Rolleis, Hasselblads, Bronicas etc. (Even though the perspective afforded by a 120-180mm lens on 6x6cm would be preferable).
That's why Pentax chose the 55mm focal length for their new 645D standard - it's the whole "a 'standard/normal' lens must give a 1 radian FOV" thing that has come down to us through photographic history. Personally I prefer either a long-standard or a moderate wideangle; if I had a 645D these would be the 75mm and 45mm lenses respectively.
Ray
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As for 6x7 format lenses beating 35mm format lenses, that's into science fiction. The whole problem associated with people making the step up from 35mm cameras to medium format (top quality in both cases) was that they assumed that they were multiplying 35mm quality by the film size factor, when the truth is that 35mm formats are such superlative peformers precisely because the designers only have to cover a small area with the 35mm format, and simply can't achieve the same degree of quality over the larger area mf presents... The only real advantage from mf has always been that of tonality. Period.
Rob C
Rob, that just ain't so. 6x7 format lenses will hardly 'beat' 35mm format lenses, but they can certainly equal them. There is/was real equality between the on-film resolution of the best 35mm and MF lenses. 80 lp/mm is quite readily attainable from both formats - more 35mm lenses might deliver it than MF lenses, but plenty of MF lenses still do. Look, for example, at Chris Perez' tests (http://www.hevanet.com/cperez/MF_testing.html). Some 35mm and MF lenses go to 120 lp/mm and beyond (including some of the MF lenses in that very test I linked to - yes, even 6x7 ones), but there are precious few films which can deliver that resolution at any sort of usable MTF contrast. All that lovely extra aerial resolution is lost in film emulsion scattering and grain effects.
This being the case, one really is "multiplying 35mm quality by the film size factor", or near enough. That's why MF film images generally appear so much more detailed than 35mm film images (as well as having better tonality in a given size of print, which I agree is indisputable). Honestly, I've never seen this dismissed before.
In fact, it is the same reason why MFD is a much harder sell than MF film was. One could move from a 35mm Leica to a Mamiya 7 and know that you would be getting 4 times the net image quality (in modern parlance, double the lp/ph in both axes). This is not the case if you move from a FF-DSLR or Leica M9 to a MFD system, which is typically only 2 times the sensor area (only 1.7 times in the case of the 645D).
Ray
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I started out with a simple question: is it possible to measure tonality using DXO, or to show us the effect in a fair side-by-side set of images. Neither of you have answered this in a sensible manner, instead you have attacked measurements in general, and focused on my photography skills (or lack thereof). I am sad to say that that kind of reaction does not make me trust your conclusions or statements.I am sorry, but this is nonsense. Arguments of the tonality of MF cameras wont make me take better pictures. If you think that, then we are indeed living on very different planets. Going out taking pictures may make me a better photograph, studying the work of others may make me a better photograph, getting critizism for my work may make me a better photograph. Thinking about composition, what is aesthetically pleasing, what draws my attention to a scene in the first place may make me a better photograph. But nit-picking about one of the supposed benefits of an expensive camera technical feature (tonality vs Sensor-size) that no-one are willing to show examples of, is almost certainly not making me a better photograph.
-h
h,
You answered your own question on the first part, so I won't bother expanding on it any further.
The second part is what I maybe did not make clear enough, and you have misunderstood.
Its not about the "benefits" of one format over another that will make you a better photographer...its knowing the DIFFERENCES.
Some of those differences can be measured, some cannot. Not because they are magic, but rather because they cannot be expressed as simple numbers. Its almost like trying to measure and define a good image and coming up with a mathematical equation to show why its good.
All I claim, is that there is a DIFFERENCE and untill you see for yourself what the difference is, you cannot decide for sure which system is best for you. Isn't the whole premise the image rather than charts and graphs?
Have a look. You might be convinced, you might not, but I can assure you that either way, you will have learned something, and learning ANYTHING, can make you a better photographer. Please don't dismiss anything as rubbish till you've gone through it and seen for yourself.
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I think that a great deal of this endless wrangling over MF versus 35mm completely misses some very important points.
If you take a photograph of a well-lit, perfectly framed subject in ideal conditions, the difference between an MF camera and something like a 5D2 or D3X in the final print will probably be utterly minimal. You would have to enlarge the shot to 36x24 or something to see any MF advantage. However, where the MF has a huge advantage and will save your arse is when things go wrong, as (in my case at least) they do so often. If the subject is a difficult one, with either too much contrast, or too little, and needs lots of post-shoot manipulation, you will find that you can push and pull the MF file around in LR or ACR or whatever far more than the 35mm one. Those big MF files will take a lot of messing with, and still look good. The huge other advantage of MF is when your framing was, shall we say, less than optimal. I can easily crop down to just 25% of the original image area and it still looks just fine printed to A3. In fact, sometimes I can get two good pictures (and different) out of one MF frame.
So for someone like me, who so often totally fouls up the shot, MF is absolutely the bee's knees :D And I'm not too proud to admit it.
John
Thank you for your opinion.
I have no objections against resolution, and accept that a good 40 megapixel camera can (given the right lenses, enough light, recording technique etc) resolve more detail than a good 15 megapixel camera. What conditions are necessary for that extra information to be relevant and important is besides the point, which is that the information potentially is there.
My original question was about the more vague "tonality". If I interpret you correctly, you find that MF files can stand more dynamic processing before artifacts like banding, noise, black/white-clipping becomes unbearable, or simply having more information hidden away in places that may not be visible using untweaked files? If that is the case, it should be relatively simple to set up a fair side-by-side test where the MF image is tweaked to "subjectively sane , good looks", and the 5Dmk2 alternative is tweaked to represent the scene similarly, but the 5Dmk2 showing artifacts, lack of shadow detail, or similar flaws. A good measurement of SNR and DR at the given camera settings should (along with e.g. examples of the noise quality) give good insight into the numbers at play?
-h
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Here are RAW-file comparisions (I think Canon 1DsIII / P65+ & D700 / P65+):
http://www.phaseone.com/de-DE/Downloads/Sample-images.aspx
You can play around with the files.
You need Capture One Pro to do so… there's a free 30day trial on the website.
Note that some images already contain settings (i.e. not "preset" settings; they are adjusted for certain purposes. There was an article these files refer to, hence the adjustments applied to the captures. But I don't know whether or not the article is still available somewhere... )
Also note that in terms of tonality a "comparision" of course is seriously limited by the quality, gamut and linearity of your monitor.
Thank you. I will try to have look at those files. Do you think that they represent a "fair comparision"? (I note that the URL seems to be that of a MF camera manufacturer)
Of course, the image display chain can be a potential limitation. I am using a new, calibrated Dell 2711 27". I guess that others here will have better displays than myself, one reason why measurements are nice to have alongside real-world images.
-h
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Do you think that they represent a "fair comparision"?
"fair" is always hard to define when you have to mix formats. Do you shoot the same horizontal dimensions? Or the same vertical? Or the same diagonal? And so on.
But I didn't look at the images in detail anyway... so I don't know.
Here's a comparision of a number of different cameras (645 + 35) that has been posted numerous times.
http://www.flickr.com/photos/dos-chin/sets/72157614936120567/
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Hi,
Here are my impressions from that test: http://echophoto.dnsalias.net/ekr/index.php/photoarticles/41-phase-one-images-for-download
In short I'd suggest it's a good comparison, except for outdoor portrait. I'd also would prefer a comparison with Nikon D3x instead of Canon 1DsIII and Nikon D700.
The reason I don't think the outdoor portrait is not a correct test is that a normal lens (50/1.8) is used at full aperture, it's just not sharp. The idea is to have short DoF, but that is better achieved with a longer lens.
It's very clear that DR in P65+ is much better than 1DsIII, it has very clear shadow detail. I have done my owns raw processing using Capture One demo to convert sample files to DNG.
Best regards
Erik
Thank you. I will try to have look at those files. Do you think that they represent a "fair comparision"? (I note that the URL seems to be that of a MF camera manufacturer)
Of course, the image display chain can be a potential limitation. I am using a new, calibrated Dell 2711 27". I guess that others here will have better displays than myself, one reason why measurements are nice to have alongside real-world images.
-h
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Hi,
I have an issue with tonality, because in my view tonality has everything to do with postprocessing and little with sensor. The sensor itself is a linear device, in essence, and just delivers a signal. Interpretation is done in postprocessing. So I cannot see how MF cameras can have better tonality. If they have better DR, that could be helpful in achieving better tonality.
I have downloaded the files and played around with them. In my view the P65+ was vastly superior to the Canon 1DsIII in DR. Both lenses had an incredible amount of lateral chroma, by the way, but that could be cleaned up in postprocessing.
My findings are here: http://echophoto.dnsalias.net/ekr/index.php/photoarticles/41-phase-one-images-for-download
I have done a similar comparison on the Leica S2, using images from "Diglloyd":
http://echophoto.dnsalias.net/ekr/index.php/photoarticles/38-observations-on-leica-s2-raw-images
The emphasis in that article was on aliasing/Moiré. If found it pretty clear that the S2 was impressive in sharpness, but I actually found that the Nikon D3X was better in DR.
Finally I also run a comparison on the Pentax 645D. In this case I made actual prints and looked mainly at resolution. The Pentax was sharper than the D3X. The images I analysed were not appropriate for checking DR, but I guess that the Pentax is pretty impressive in the DR area.
http://echophoto.dnsalias.net/ekr/index.php/photoarticles/51-a-closer-look-at-pentax-645d-image-quality
Some unexpected Moiré was visible. I have seen some aliasing in most MF samples I looked at carefully, so lack of OLP-filtering comes with a price.
To sum it up: the samples I have seen deliver on promise regarding sharpness. I don't think that Leica S2 has better DR than Nikon D3X. Aliasing may be a problem at some times. It seems that stopping down to f/11 on 6 micron pitch sensors can eliminate most aliasing artifacts due to diffraction.
Best regards
Erik
Here are RAW-file comparisions (I think Canon 1DsIII / P65+ & D700 / P65+):
http://www.phaseone.com/de-DE/Downloads/Sample-images.aspx
You can play around with the files.
You need Capture One Pro to do so… there's a free 30day trial on the website.
Note that some images already contain settings (i.e. not "preset" settings; they are adjusted for certain purposes. There was an article these files refer to, hence the adjustments applied to the captures. But I don't know whether or not the article is still available somewhere... )
Also note that in terms of tonality a "comparision" of course is seriously limited by the quality, gamut and linearity of your monitor.
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It seems that stopping down to f/11 on 6 micron pitch sensors can eliminate most aliasing artifacts due to diffraction.
depends on the lenses. The 65+ bridge shot from that comparision is at f11 and shows moiré (at infinity). I've also seen other f11 shots from a P40+ / P65+ showing moiré. Both are 6µm sensors.
My P45 (6.8µm) shows moiré even at f16... depending on the lens.
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back to the 645D 55mm....
what does give your lens stopped down ?(the one you bought, not the brick wall tests found on the web)
are those soft edges still here at f/11 ?
can you show us an uncropped picture too ? because we don't have any idea about the size of your crop :/