Luminous Landscape Forum
Equipment & Techniques => Medium Format / Film / Digital Backs – and Large Sensor Photography => Topic started by: ErikKaffehr on July 05, 2014, 04:22:30 am
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Hi,
Lloyd Chambers is testing the Pentax 645Z, the impression I have that the test is still in progress.
This far it seems that he is a bit skeptical to the 645Z as he feels that the lenses are not good enough to match the top notch lenses from Leica on the S or the best lenses for 135. Lloyd had a direct shootout with the 645Z using the 25/4 comparing it with a 21/2.8 Zeiss adapted to a Sony Alpha 7r. In that case the Zeiss/Sony combo was better in all aspects.
I would say that the article is worth the 49$ subscription price, keeping in mind that Lloyd is a real pixelpeeper.
Best regards
Erik
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Hi,
Lloyd Chambers is testing the Pentax 645Z, the impression I have that the test is still in progress.
This far it seems that he is a bit skeptical to the 645Z as he feels that the lenses are not good enough to match the top notch lenses from Leica on the S or the best lenses for 135. Lloyd had a direct shootout with the 645Z using the 25/4 comparing it with a 21/2.8 Zeiss adapted to a Sony Alpha 7r. In that case the Zeiss/Sony combo was better in all aspects.
I would say that the article is worth the 49$ subscription price, keeping in mind that Lloyd is a real pixelpeeper.
Best regards
Erik
Tell us more ...
We don't all have the time to read the book, but we enjoy reviews :)
Edmund
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If adapted manual focus lenses are included, keep in mind that the 645Z can also use Carl Zeiss/Hasselblad V and Pentax 6x7 lenses, among others.
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Hi,
Lloyd's is a commercial site, so I guess that I am not allowed to disclose to much. Also, I think the article is still in progress.
The impression I have that new lenses are needed to keep the MF advantage over 135 now that we have some very good performers.
Best regards
Erik
Tell us more ...
We don't all have the time to read the book, but we enjoy reviews :)
Edmund
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Hi,
I have five Hasselblad lenses 40/4 FLE, 50/4 FLE, 80/CFE, 120/CFi and 180/CFi, based on that experience I don't think they would keep up with top grade 135 lenses on a 36 MP sensor. For long time I have been shooting Pentax 67 and my hunch is they are a bit weaker than the Zeiss lenses.
The modern 135 Zeiss lenses are awesome. The MTFs for the 21/2.8 and 100/2.0 are enclosed and so is the MTF for the 150/4 Sonnar 150/4 for the Hasselblad. I also added the MTF curves for the 40/4 Distagon FLE which is the widest lens for the V-system (except the Biogon 38 and the 30 mm fisheye).
There is a newer version of the Distagon 40/4 called 40/4 IF CFE. That lens has a much improved design, but is not easy to find and very expensive.
If you happen to have a set of Pentax MF lenses and want a digital body, I would say both the P645D and the P645Z are very attractive. With Hasselblad lenses I would rather go with a Hasselblad body and a used Phase One/Hasselblad/Leaf back.
Myself, I have a Hasselblad 555 ELD with a P45+ back. I can just compare it to my Sony Alpha 99, which is 24MP full frame, and a couple of zooms. There is a resolution advantage to the Hassy/P45+ but I don't feel it is visible in print, up to say A2 size.
Best regards
Erik
If adapted manual focus lenses are included, keep in mind that the 645Z can also use Carl Zeiss/Hasselblad V and Pentax 6x7 lenses, among others.
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Hi,
Lloyd's is a commercial site, so I guess that I am not allowed to disclose to much. Also, I think the article is still in progress.
The impression I have that new lenses are needed to keep the MF advantage over 135 now that we have some very good performers.
Best regards
Erik
I think you are allowed to disclose a decent amount - this is called fair use under copyright law.
I used to have a subscription to Lloyd's site but dropped it because I shoot people and he shoots landscapes and so the aspects of a camera he discusses - resolution, distorsion etc - are not those which matter most to me ie. AF usability, skin tone, available light, quick focus check on back display. I find Michael's comments on cameras to be interesting because they reflect real world "stress" experience - ie. what happens when camera rubber hits the road.
Edmund
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Hi,
Well, Lloyd uses to test equipment for a longer period, so I guess more information is coming. Right now he writes most about the lenses.
Clearly, the sensor is larger than 135, so if we assume it is like other Sony sensors it would have some advantage in DR, and probably one EV in high ISO capability.
I guess colour rendition is pretty much depending on camera profiles. Lloyd discusses it based on the Adobe Standard Profile and the embedded profile. As a landscape shooter, I don't know. In practice, I also feel that white balance plays a major role. If the camera has a good automatic WB it is most helpful.
Issues Lloyd mentions is that the shutter may cause vibrations and the camera lacks electronic first curtain which he feels may mitigate the problem, if the problem exists. He is also missing an electronic viewfinder, but I guess most buyer prefer an optical one.
Best regards
Erik
I think you are allowed to disclose a decent amount - this is called fair use under copyright law.
I used to have a subscription to Lloyd's site but dropped it because I shoot people and he shoots landscapes and so the aspects of a camera he discusses - resolution, distorsion etc - are not those which matter most to me ie. AF usability, skin tone, available light, quick focus check on back display. I find Michael's comments on cameras to be interesting because they reflect real world "stress" experience - ie. what happens when camera rubber hits the road.
Edmund
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Issues Lloyd mentions is that the shutter may cause vibrations and the camera lacks electronic first curtain which he feels may mitigate the problem, if the problem exists.
Hi Erik,
It may...
It sounds like he's stating the obvious, isn't he? One may hope he actually will test it over a range of shutterspeeds. From other tests, does it look like he has a procedure in place that produces quantifiable results for that?
Cheers,
Bart
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Hi,
He mentions it as a potential problem. Similar problems have been reported on Phase One cameras and I think also the 645D. Lloyd has discovered the problem on the A7r and showed examples of it. He didn't quantify it, that takes some kind of analysis. Jim Kasson has done an excellent analysis on the A7r.
That is the reason I wrote may…
Now, some MFD cameras use leaf shutters, which are said to be essentially vibration free, that may be a consideration.
Best regards
Erik
Hi Erik,
It may...
It sounds like he's stating the obvious, isn't he? One may hope he actually will test it over a range of shutterspeeds. From other tests, does it look like he has a procedure in place that produces quantifiable results for that?
Cheers,
Bart
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ie. what happens when camera rubber hits the road.
Or when lens hits the road ;D
Kumar
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I am not surprised by the "negative" Lloyd comments. Sure most of the existing P645 lenses, are not up the standards of the sensor, as most are over 5 years old and many pre-date the 645D. the 35mm FA, 33-55mm Zoom both were very good lenses and I guess still are. The 25mm results surprised me a bit, but it also could be a not so perfect copy.
Lloyd is not a fan of MFD, and in fact has usually found ways to write against it in his reports/blogs. He is also very concerned about exacting focus issues that I believe in the real world of photographic printing may be a bit overdone. But that is just one voice in the wilderness.
He also tends to miss the big picture, i.e. what the total solution from Pentax with the 645Z can offer to a photographer.
But I am glad to see he now is seeing good results with the A7r, as for the longest time, that was his bully pulpit with the issues around the shutter shake.
Each photographer interested in this system, should take the time to demo the camera if at all possible and see if it meets their needs and their workflow.
Paul
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Hi Paul,
Thanks for responding, always a nice to see your view!
Regarding Lloyd's comments, I actually would say it is a bit interesting. Now, he actually shows a lot of images. Sometimes he also posts raw images. So any reader can make his opinion based on the images actually shown.
Regarding the A7r shutter vibration, it is obviously an issue in say the 1/15s to 1/125s range. Unfortunately this is exactly where I mostly end up. The image degradation is not to bad, something like shooting 24 MP instead of 36 MP, or so. Jim Kasson has looked into this a lot, and found that is was very hard to surpass the image quality of A7 with the A7r under those conditions. As it is now, I am not really interested in the A7/A7r, anyway. I always carry a 70-400/4-5.6 lens, so size matters little to me.
Now, getting back to the P645Z, Lloyd has tested a lot of the old Pentax lenses, and they were not very good. I never had a Pentax 645, but I do have a Pentax 67, and those lenses are not as good as my Hasselblad lenses, what I have seen. I am pretty sure that modern lenses are sharper than my old Hasselblad lenses. Now, sharper is not necessarily better. There is a lot more to a picture than sharpness. Right now, I am warming up a bit to the Hasselblad, BTW.
In a way, I feel that Lloyd is focusing a bit to much on sharpness. With the DSLRs I focus using magnified live view, whenever I can. Focusing the Hasselblad is for me a bit hard, I have made a special eyepiece adjusted for my vision, or I used a 3X magnifier. The magnifier worked pretty well, but it doesn't work with my adapted ocular.
Lloyd also found that AF isn't really exact. He has pretty good evidence for that.
Now, sharpness may not be the ultimate factor, but the P645Z uses essentially the same sensor as the Nikon D800 or the Sony Alpha 7r, just a bit larger. The size has an advantage with regard to DR, high ISO, resolution and not much else. So I feel that it is good that Lloyd presents his findings, with accompanying high resolution images.
Other factors may play a significant role. I have found that a good automatic white balance plays an important role. A good camera profile may be helpful with colour, and some profiles may work well for skin tones. As a landscape shooter I don't know that much about skin tones. I am pretty sure that interpretations differ.
Best regards
Erik
I am not surprised by the "negative" Lloyd comments. Sure most of the existing P645 lenses, are not up the standards of the sensor, as most are over 5 years old and many pre-date the 645D. the 35mm FA, 33-55mm Zoom both were very good lenses and I guess still are. The 25mm results surprised me a bit, but it also could be a not so perfect copy.
Lloyd is not a fan of MFD, and in fact has usually found ways to write against it in his reports/blogs. He is also very concerned about exacting focus issues that I believe in the real world of photographic printing may be a bit overdone. But that is just one voice in the wilderness.
He also tends to miss the big picture, i.e. what the total solution from Pentax with the 645Z can offer to a photographer.
But I am glad to see he now is seeing good results with the A7r, as for the longest time, that was his bully pulpit with the issues around the shutter shake.
Each photographer interested in this system, should take the time to demo the camera if at all possible and see if it meets their needs and their workflow.
Paul
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Hello Erik
Your points are good ones. I agree a weakness for Pentax is current lenses. In a way this is similar issue for Nikon and 36MP sensors as I have found that various nikkor lenses aren't quite up to the 36MP of the sensor.
I have held off of the A7r, for a few reasons, not as much the shutter vibration issue as the limited number of Sony FE mounts, and the fact that no Nikon lens will mount and use AE or AF. (Not to mention Sony refuses to make a wired intervalometer so tiime laspe work with the Sony a7 series is limted to 30 seconds per expsoure) Sad as the body is really perfect for timelaspe work.
I am looking forward to seeing how Nikon implemented the electronic first curtain on the new D810.
As for Pentax, I personally don't feel the older 67 lenses will work much better as I used many of them on a 1ds MKII and 5D MKII with a zork adapter and found them a bit soft for my liking.
One thing I have to give Lloyd credit for is he is very through in his reports :-)
Paul
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If you happen to have a set of Pentax MF lenses and want a digital body, I would say both the P645D and the P645Z are very attractive.
This is why I bought my 645D. I sold off the 645 film body long ago but kept the lenses because I liked the way they render. Recently I did an informal comparison between the Pentax/75mm and Sony A7r/55mm combos. My conclusion, evaluating 15x20" and 14x21" prints, is that the Sony/55 gives an impression of greater clarity...wonderful for urban landscapes and (probably) desert/mountainous terrain. The Pentax/75 offers less abrupt tonality, leading to a gentler overall look...lovely when applied to the world of living things. Both systems are overkill resolution-wise for my printing needs and should be easily up to the task of an eventual 8k display system. Also, judging by Ming Thein's review photos (taken with the Pentax 75), the 645Z does a nice job of splitting the difference between my two systems.
-Dave-
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Hi,
Did I have a set of lenses, I may have ended buying the Pentax 645D, too.
The comparison Lloyd made with the P645Z using the 25/4 and the Sony Zeiss combo it was really pretty close. According to the samples he shown the Sony/Zeiss was better but not by a lot.
But, the 645/4 lens costs 4,496.95$ at B&H while the Zeiss 21/2.8 costs 1843$ and the Sony A7r 2298$, so the Sony with the Zeiss costs less than Pentax lens alone. That said, the 25 mm may be the most expensive lens in the Pentax line up. The samples I have seen from the P645D were all pretty sharp.
Lloyd has also tested the 90/2.8 macro and says it is very good.
Normally he shoots a mosaic for testing with the option to select different aperture camera combos using buttons. Very illustrative.
Best regards
Erik
This is why I bought my 645D. I sold off the 645 film body long ago but kept the lenses because I liked the way they render. Recently I did an informal comparison between the Pentax/75mm and Sony A7r/55mm combos. My conclusion, evaluating 15x20" and 14x21" prints, is that the Sony/55 gives an impression of greater clarity...wonderful for urban landscapes and (probably) desert/mountainous terrain. The Pentax/75 offers less abrupt tonality, leading to a gentler overall look...lovely when applied to the world of living things. Both systems are overkill resolution-wise for my printing needs and should be easily up to the task of an eventual 8k display system. Also, judging by Ming Thein's review photos (taken with the Pentax 75), the 645Z does a nice job of splitting the difference between my two systems.
-Dave-
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As someone who has witnessed Lloyd's 'testing' method first hand, I wouldn't put much stock into his conclusions. Anyone including Lloyd can make soft, out of focus images on subject matter like moving water that are meaningless for evaluating performance of a camera system. Twenty duff images in a row proves nothing if the 21st is sharp. I'd wait for someone who is interested in finding the best in a system and has experience enough with MF to know what to look for to come along and test.
I haven't been a public fan of DXO's Medium format testing, however they look like stars with their scientific and repeatable testing methodology, compared to seat of the pants judgment calls like Lloyd calling out 2 stops difference in dynamic range between two outdoor shots based on his own judgement and not counting differences in things like time of day, clear or overcast sky. I get the sense that Lloyd has certain goals, because no one could make those kind of unsubstantiated claims for long without being called to prove it. Oh yeah, he doesn't allow comments on his blog. Hmm….
I came across Martin Zimelka's reviews the other day. http://www.martinzimelka.com/homepage/Welcome.html
Now here's a guy who really writes a through review, knows about photography, is passionate about image making, and share's his knowledge for free. That's the way it should be IMHO.
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Hi Bart,
This figure shows the shutter related vibration on the A7r quite quantifiably:
(http://blog.kasson.com/wp-content/uploads/2014/03/MTF50-a7r-55.png)
Full article: http://blog.kasson.com/?p=5296
The amount of sharpness lost depends on the masses involved, elasticity and dampening of the tripod, choice of suspension point, etc.
The curve below shows the effect on MTF of "electronic first curtain" of the A7, HE means Horisontal with EFC.
(http://blog.kasson.com/wp-content/uploads/2014/03/mtf50a7180h.png)
Best regards
Erik
Hi Erik,
It may...
It sounds like he's stating the obvious, isn't he? One may hope he actually will test it over a range of shutterspeeds. From other tests, does it look like he has a procedure in place that produces quantifiable results for that?
Cheers,
Bart
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second graph valley is surprising. why? why?
Hi Bart,
This figure shows the shutter related vibration on the A7r quite quantifiably:
(http://blog.kasson.com/wp-content/uploads/2014/03/MTF50-a7r-55.png)
Full article: http://blog.kasson.com/?p=5296
The amount of sharpness lost depends on the masses involved, elasticity and dampening of the tripod, choice of suspension point, etc.
The curve below shows the effect on MTF of "electronic first curtain" of the A7, HE means Horisontal with EFC.
(http://blog.kasson.com/wp-content/uploads/2014/03/mtf50a7180h.png)
Best regards
Erik
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Hi,
A good question. The difference is the behaviour of the first curtain. On a mirrorless camera the shutter needs to be closed pre exposure and that causes vibrations. But, it seems that the opening of the shutter causes most vibration. With a short exposure it will not affect resolution that much as motion is probably slow. Conservation of momentum essentially says that if shutter is 1g and moves at 10 m/s and the camera is say 500 g it will move at 1/50 m/s. So say with 10 ms exposure we will have 1/5000 mm motion not noticable. But with 1/10 s we will have 2 microns of motion, and that will be visible. With longer times the motion will be absorbed (or arrested?) by the mass of the tripod and sharpness improve again.
No great physics… but I guess you see my point.
These images, using a thermonuclear D50 illuminant at 93e6 miles distance ( http://www.space.com/17081-how-far-is-earth-from-the-sun.html) , show the loss off sharpness: http://blog.kasson.com/?m=20140110
Best regards
Erik
second graph valley is surprising. why? why?
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This figure shows the shutter related vibration on the A7r quite quantifiably:
Yes, something like that is what one would hope for. Obviously, large mirrors, and large curtain shutters (especially the faster traveling ones), will need to abruptly move more mass and thus create more opportunity to cause vibrations, duh.
The question then becomes, how well engineered are the counter measures, and do they result in a workable solution? One also has to consider that comparisons between different sensor dimensions need to be normalized, because larger sensors require less magnification for the same targeted output size. A Lines-Per-Picture-Height (LPPH) metric allows to do just that. Only showing cropped image sections is not enough for comparison between platforms, one needs to quantify, and then normalize.
Cheers,
Bart
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Yes, something like that is what one would hope for. Obviously, large mirrors, and large curtain shutters (especially the faster traveling ones), will need to abruptly move more mass and thus create more opportunity to cause vibrations, duh.
The question then becomes, how well engineered are the counter measures, and do they result in a workable solution? One also has to consider that comparisons between different sensor dimensions need to be normalized, because larger sensors require less magnification for the same targeted output size.
If the pixels are of equal quality, why is sensor size relevant?
Cheers,
Bernard
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If the pixels are of equal quality, why is sensor size relevant?
Hi Bernhard,
Two ways of looking at it.
To magnify from a sensor size to an output size, say a physically larger sensor e.g. 32.8mm versus 24mm, will require 26.8% less magnification to achieve the same output size. If the sensor arrays have similar sensel pitch, the physically larger sensor will have 36.7% more sensels and therefore higher resolution at the output size.
Alternatively, the sensel pitch of the physically larger sensor array could also be larger, which would reduce the resolution advantage proportionally with increasing pitch size. If the pitch size would be such that both sensor arrays have the same number of sensels (vertically), then the larger sensels of the physically larger sensor would still achieve a higher MTF, because of larger image magnification (assuming optics with the same angle of view) of the same features that are projected on the sensor, and we know that MTF reduces towards smaller details, higher spatial frequencies.
So that's why the LPPH are needed to normalize comparisons of differently sized sensors.
Cheers,
Bart
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Hi,
As it seems now, we know we have an issue with vibration on the A7r. Lloyd found a way to mitigate it, using a camera flash as additional weight.
It is a bit odd that Lloyd gets blame for discovering the problem. Some testers have not seen it, I guess they are not observant enough, or just overenthusiastic about their system.
Getting back to the 645D, we know that it may be a problem. The issue was seemingly noted on the 645D, but it seems that the shutter was reworked. The problem is probably observable on very high resolution detail, when shooting from a tripod. Lloyd had a USAF type test target in one of his shot which indicated the problem quite clearly on the Sony A7r.
Jim Kasson also measured the Nikon D800 (or D800E) and it also had a measurable vibration, but almost an order of magnitude less than the A7r.
It is really a part of the problem with high resolution, there are a lot of ways to loose it.
Best regards
Erik
Hi Bernhard,
Two ways of looking at it.
To magnify from a sensor size to an output size, say a physically larger sensor e.g. 32.8mm versus 24mm, will require 26.8% less magnification to achieve the same output size. If the sensor arrays have similar sensel pitch, the physically larger sensor will have 36.7% more sensels and therefore higher resolution at the output size.
Alternatively, the sensel pitch of the physically larger sensor array could also be larger, which would reduce the resolution advantage proportionally with increasing pitch size. If the pitch size would be such that both sensor arrays have the same number of sensels (vertically), then the larger sensels of the physically larger sensor would still achieve a higher MTF, because of larger image magnification (assuming optics with the same angle of view) of the same features that are projected on the sensor, and we know that MTF reduces towards smaller details, higher spatial frequencies.
So that's why the LPPH are needed to normalize comparisons of differently sized sensors.
Cheers,
Bart
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Erik
I noticed Nikon moved to an electronic first curtain on the D810. They may found the same issue you noted. In my usage with the D800 I really cant say I have noticed the issue either when hand held or on tripod.
Paul
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Actually, the thing might resonate with a strong Q factor at a frequency near 1/25s or 1/12s and the Q factor means that the double shock causes the visible degradation there, with the system being fairly well baflled with respect to other frequencies.
Update - this is trash of course if that camera does not have a double shutter shock (electronic first curtain)
Edmund
Hi,
A good question. The difference is the behaviour of the first curtain. On a mirrorless camera the shutter needs to be closed pre exposure and that causes vibrations. But, it seems that the opening of the shutter causes most vibration. With a short exposure it will not affect resolution that much as motion is probably slow. Conservation of momentum essentially says that if shutter is 1g and moves at 10 m/s and the camera is say 500 g it will move at 1/50 m/s. So say with 10 ms exposure we will have 1/5000 mm motion not noticable. But with 1/10 s we will have 2 microns of motion, and that will be visible. With longer times the motion will be absorbed (or arrested?) by the mass of the tripod and sharpness improve again.
No great physics… but I guess you see my point.
These images, using a thermonuclear D50 illuminant at 93e6 miles distance ( http://www.space.com/17081-how-far-is-earth-from-the-sun.html) , show the loss off sharpness: http://blog.kasson.com/?m=20140110
Best regards
Erik
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If the pixels are of equal quality, why is sensor size relevant?
Sensor size relates to system resolution, so lenses with equal lp/mm resolution will produce higher system resolution on the system with the larger sensor.
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Hi,
I guess that electronic first curtain is a property of the sensor, not the camera.
Regarding the shutter vibration on the A7r, it is more measurable than visible. You can observe it as a softening of the image at certain exposure times, or drop in MTF. No double contours, or so.
The D800 has something like 1/8 of the vibrations compared to the A7r, as I recall, so it would not cause a visible degradation.
Here is an actual measurement by Mike Colette:
(http://www.kasson.com/ll/a7R_shutter_annotated.png)
Full size:
http://www.kasson.com/ll/a7R_shutter_annotated.png
Full article here: http://blog.kasson.com/?p=4459
Best regards
Erik
Erik
I noticed Nikon moved to an electronic first curtain on the D810. They may found the same issue you noted. In my usage with the D800 I really cant say I have noticed the issue either when hand held or on tripod.
Paul
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Hoping for discussion of the Pentax 645z, and a bit disappointed to see that this thread has wandered off to other subjects.
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Hi,
Good point.
Here is how I see it. Lloyd has reviewed cameras for a long time, so he has a good insight in the qualities of different systems. He tests a lot of gear, and he likes some more and some less. The point is that he has a wide experience.
The point has been made that he is not into medium format, which is quite true. He has tested several MF format cameras. He tested the Mamiya DL28 with a Leaf Aptus II-6, the Pentax 645D, Leica S2, Hasselblad H4D50 and now he is testing the Pentax 645Z. Of the cameras he tested I guess the only one he really liked is the Leica S2. The Hasselblad was quite OK, I think, but he felt it was to large. He was also impressed by the DL28, but times are changing and competition from affordable DSLR technology is more intense.
Lloyd generally has issues with AF, he finds it is not reliable enough. I don't know what is reality. Lens rentals had a series of articles on AF on Nikons and Canons, and it is pretty clear that neither system can focus accurately, except latest generation Canon bodies and the latest generation Canon lenses seem to focus very well. Lloyd generally finds that live view based focusing is needed for accurate focus, period.
Regarding his testing he essentially does a lot of comparison shots. The best one is probably a mosaic in front of some university close by. Very good detail at near infinity. He makes aperture series. Lloyd spends a lot of effort on presentation, you can instantly switch between images, which is good for comparison. Most of the images are at actual pixels.
He also has some table top images, that add depth. In such an image only a small part is in accurate focus, but it is possible to study bokeh. He also shoots some outdoor subjects, these are mostly intended for checking rendition. Focus in these cases is not crucial. You simply look for a point that is in focus.
Getting back to the Pentax 645Z. I would say that he likes the camera. It is probably the most advanced and well designed MF DSLR. But, he has some reservations. Mostly the price. He feels that the lenses are good enough, but not really excellent. AFAIK he has to date tested two lenses on the P 645Z, the 90 mm macro and the 25/4. Both lenses are good, but the 25/4 lacks the bite of a really excellent lens. He compared it with the Sony Alpha 7r using a Zeiss 21/2.8 lens. The Zeiss 21/2.8 and A7r combo costs less than the Pentax 645Z lens alone, but in the test shot he made the Sony A7r/Zeiss combo outperformed the Pentax combo at all apertures and across the field. So, he asks why, pay 2-3 times the money for no better results?
He usually test stuff for a couple of months, so we are at the beginning of this test.
Issues he doesn't really go into is tethering, flash, skin tones etc. He usually looks at DR and noise. I am pretty sure that the P645Z excels in DR. Regarding colour rendition I guess it is OK. What I think is that much effort goes into profile development at Phase One and Hasselblad, giving those cameras some subtle benefits in skin tones. I guess that the Pentax can produce 'accurate' color, that is accurate in the measurable sense. DR is probably just fine. It is a Sony sensor and they used to be excellent.
So, to sum it up:
Lloyd likes the camera, but he is skeptical about the value. The camera itself is great, but the lenses are OK but not as good as the latest generation of DSLR lenses from Zeiss and Sigma. Canon and Nikon can make nifty lenses, too. The Canon T&S lenses are quite workable with medium format backs, for instance.
Best regards
Erik
Hoping for discussion of the Pentax 645z, and a bit disappointed to see that this thread has wandered off to other subjects.
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Thanks.
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I had an opportunity a few days ago to witness my photographer friend testing both Pentax 645Z and Leica S. Pentax with the tele 150mm and Leicas S with Macro 120mm f2.5, ha gave me couple of raw file to do the comparison and this is the result. Both shot at same EV, WB. The skin tone in Pentax looks flat and couldn't render red very well, not sure if this has anything to do with being CMOS sensor.
(https://farm3.staticflickr.com/2909/14602404145_ae2f0234b7_b.jpg)
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I had an opportunity a few days ago to witness my photographer friend testing both Pentax 645Z and Leica S. Pentax with the tele 150mm and Leicas S with Macro 120mm f2.5, ha gave me couple of raw file to do the comparison and this is the result. Both shot at same EV, WB.
Did that same EV setting result in equal exposure levels of Raw data? IOW, are both cameras equally sensitive, e.g. when set to ISO 100? The White Balance setting upon shooting is not relevant for Raw's, the WB as determined by the Raw converter is.
The skin tone in Pentax looks flat and couldn't render red very well, not sure if this has anything to do with being CMOS sensor.
No, it has nothing to do with CMOS. The only thing that matters are the characteristics of the Bayer CFA filters used. More relevantly, which camera profile was used for the Leica S and for the Pentax 645Z?
It's known that C1 does not always handle DNGs all that well as other native Raw formats, so that may say more about that than about the camera ... Did you also compare in e.g. Lightroom?
Cheers,
Bart
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Did that same EV setting result in equal exposure levels of Raw data? IOW, are both cameras equally sensitive, e.g. when set to ISO 100? The White Balance setting upon shooting is not relevant for Raw's, the WB as determined by the Raw converter is.
No, it has nothing to do with CMOS. The only thing that matters are the characteristics of the Bayer CFA filters used. More relevantly, which camera profile was used in C1 for the Leica S and for the Pentax 645Z?
It's know that C1 does not always handle DNGs all that well as other native Raw formats, so that may say more about that than about the camera ... Did you also compare in e.g. Lightroom?
Cheers,
Bart
Yes both were set equally, WB were set is LR, temp-5000 and tint-0, and camera/lens profile disabled.
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Hi,
Lloyd wrote about Lightroom having two profiles for the Pentax 645Z. There is the Adobe Standard profile and an embedded profile coming from Pentax.
They are quite different.
Best regards
Erik
Did that same EV setting result in equal exposure levels of Raw data? IOW, are both cameras equally sensitive, e.g. when set to ISO 100? The White Balance setting upon shooting is not relevant for Raw's, the WB as determined by the Raw converter is.
No, it has nothing to do with CMOS. The only thing that matters are the characteristics of the Bayer CFA filters used. More relevantly, which camera profile was used in C1 for the Leica S and for the Pentax 645Z?
It's known that C1 does not always handle DNGs all that well as other native Raw formats, so that may say more about that than about the camera ... Did you also compare in e.g. Lightroom?
Cheers,
Bart
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I had an opportunity a few days ago to witness my photographer friend testing both Pentax 645Z and Leica S. Pentax with the tele 150mm and Leicas S with Macro 120mm f2.5, ha gave me couple of raw file to do the comparison and this is the result. Both shot at same EV, WB. The skin tone in Pentax looks flat and couldn't render red very well, not sure if this has anything to do with being CMOS sensor.
(https://farm3.staticflickr.com/2909/14602404145_fb52afef01_o.png)
Hello,
This is interesting. Could you post the dng files?
If you have space issues, you can dropbox or send them to yourself with yousendit.com and post the links.
Edmund
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Bart,
how do you *know* that? yes, the CFAs define much of camera color, but texture is a different story. From the out of sensor internal Raws (not camera raws) I've seen from sensors similar to Blackmagic's, a huge amount of filtering sometimes needs to be done to solve pattern noise issues and make a CMOS image usable. Intensive filtering will destroy the texture, you won't get it back.
Edmund
No, it has nothing to do with CMOS. The only thing that matters are the characteristics of the Bayer CFA filters used.
Cheers,
Bart
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Lloyd wrote about Lightroom having two profiles for the Pentax 645Z. There is the Adobe Standard profile and an embedded profile coming from Pentax.
They are quite different.
Hi Erik,
Then that's an issue. It might be interesting to try in RawTherapee if that supports the 645Z DNGs or PEFs, e,g, with the IQ250 profile from Capture One. Alternatively one could create a DNG profile from a colorchecker for use in ACR/LR.
Cheers,
Bart
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Hi Erik,
Then that's an issue. It might be interesting to try in RawTherapee if that supports the 645Z DNGs or PEFs, e,g, with the IQ250 profile from Capture One. Alternatively one could create a DNG profile from a colorchecker for use in ACR/LR.
Cheers,
Bart
You can also use Adobe's DNG color editor to play with the primaries and create a matrix that looks good on the fly. Portrait use is not about accurate color, it's all about pretty color.
It's clear that in those pics something is very different. But that doesn't mean it's the camera's fault, nor does it mean it's just the profile. For all I know the lighting may have changed.
Edmund
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You can also use Adobe's DNG color editor to play with the primaries and create a matrix that looks good on the fly. Portrait use is not about accurate color, it's all about pretty color.
I agree.
Cheers,
Bart
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The best one is probably a mosaic in front of some university close by.
Erik, that's Memorial Church at Leland Stanford Junior University. There is no Leland Stanford Senior University.
Jim
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I had an opportunity a few days ago to witness my photographer friend testing both Pentax 645Z and Leica S. Pentax with the tele 150mm and Leicas S with Macro 120mm f2.5, ha gave me couple of raw file to do the comparison and this is the result. Both shot at same EV, WB. The skin tone in Pentax looks flat and couldn't render red very well, not sure if this has anything to do with being CMOS sensor.
(https://farm3.staticflickr.com/2909/14602404145_ae2f0234b7_b.jpg)
A 400 px wide screen capture hardly does justice to either image, but the main difference appears to be color balance. Certainly microcontrast and sharpness would not be faithfully reproduced in the screen capture. A simple MatchColors in Photoshop with the Pentax image ase the target removes many of the differences.
Bill
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Hi,
Lloyd has now added a set of freehand portrait shots, in part with high ISO using the 90 macro.
Observations:
- Lens is sharp and has very good bokeh
- Autofocus works really well (normal phase detecting AF)
- Mirror is klunky, but no vibrations
- High ISO images very good, better than DSLRs
On the minus side:
- Exposure was not reliable (very odd in my view)
- The camera is heavy
So he likes the camera and the results.
Still some reservations about the lenses, but the ones he tested seem to be pretty good.
Best regards
Erik
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I had an opportunity a few days ago to witness my photographer friend testing both Pentax 645Z and Leica S. Pentax with the tele 150mm and Leicas S with Macro 120mm f2.5, ha gave me couple of raw file to do the comparison and this is the result. Both shot at same EV, WB. The skin tone in Pentax looks flat and couldn't render red very well, not sure if this has anything to do with being CMOS sensor.
(https://farm3.staticflickr.com/2909/14602404145_ae2f0234b7_b.jpg)
Interesting, and thanks for sharing the images. The Leica image has more appearance of depth to me plus the obvious color differences. I guess the color can be sorted out by guys like Edmund with custom profiles etc, but what about the depth? It's all an illusion so no doubt not all will see it the same way.
You guys can debate about whether this is CCD vs CMOS or Leica lenses vs Pentax but it can't be about format size since they are similar sizes - both sort of 'tweeners." I'm understand that CMOS should be the same but I have always seen the CMOS images as flatter and that's most probably due to different camera optimizations - most CMOS cameras seem to be set up for higher ISO work while most high end CCD cameras are optimized for best IQ at base.
Does anyone have any information on how the new Pentax does with tethering? Max Sync speed? Very curious to see some movie clips from this camera.
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The D800 has something like 1/8 of the vibrations compared to the A7r, as I recall, so it would not cause a visible degradation.
The D800 shooting in live view has the same movement of the shutter as the A7R, but the D800 has another option to avoid the double movement by choosing MUP. Using MUP in LV mode means that the first click of the shutter closes the shutter and the next click of the shutter will open the shutter to start the exposure. This means the shutter shock can be (almost) avoided. Clearly the EFC is a better solution and makes the use of MUP redundant.
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Eric,
One can doubtless match *one* image; one won't (math proof etc) be able to color-match all images; whether the Leica (Kodak) or Pentax (Sony) CFA is "better" in practice will be up to the user, and subject matter. But skin, landscape etc depends a lot on texture rendering and this may well differ from camera to camera at least as much as the color; here the images are small so texture cannot be examined. One advantage of the Sony is that one can protect highlights by massive underexposure eg. 3 stops, and lift afterwards; this might become standard practice, and avoid issues with forehead, cheekbone, nose etc speculars ...
Edmund
Interesting, and thanks for sharing the images. The Leica image has more appearance of depth to me plus the obvious color differences. I guess the color can be sorted out by guys like Edmund with custom profiles etc, but what about the depth? It's all an illusion so no doubt not all will see it the same way.
You guys can debate about whether this is CCD vs CMOS or Leica lenses vs Pentax but it can't be about format size since they are similar sizes - both sort of 'tweeners." I'm understand that CMOS should be the same but I have always seen the CMOS images as flatter and that's most probably due to different camera optimizations - most CMOS cameras seem to be set up for higher ISO work while most high end CCD cameras are optimized for best IQ at base.
Does anyone have any information on how the new Pentax does with tethering? Max Sync speed? Very curious to see some movie clips from this camera.
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It's clear that in those pics something is very different. But that doesn't mean it's the camera's fault, nor does it mean it's just the profile. For all I know the lighting may have changed.
When two things are different, it is not always the case that one is objectively better and the other objectively worse. Sometimes two different things are just... different. Certainly in these sample images we have a difference in color rendition. But that could be attributed to a number of things other than the camera's intrinsic capabilities.
Also, it should almost be a rule that when people share photographs from some automatically highly regarded brand such as Hasselblad and some new kid on the block (sort of) like Pentax and the sample images should be offered without brand identification. That would help us see the images more objectively and help viewers avoid confirmation bias that is surely present for many when the Big H brand name is mentioned.
Dan
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Hi,
I am not sure that the cocking of the shutter is the main cause of vibrations on the A7r. A smart engineer has actually measured the camera oscillation using a speaker coil as pickup and an oscilloscope. Clearly, most of the oscillation is coming from the acceleration and retardation of the shutter curtains themselves.
Therefore, I don't think a firmware solution is possible.
Adding the right weight reduces the problem significantly, it seems.
Best regard
Erik
The D800 shooting in live view has the same movement of the shutter as the A7R, but the D800 has another option to avoid the double movement by choosing MUP. Using MUP in LV mode means that the first click of the shutter closes the shutter and the next click of the shutter will open the shutter to start the exposure. This means the shutter shock can be (almost) avoided. Clearly the EFC is a better solution and makes the use of MUP redundant.
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Still waiting for someone -- anyone -- to suggest an in-principle basis for any claimed benefit of CCD over CMOS. All can play.
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Hi,
In continued testing Lloyd was shooting some freehand portraits using high ISO. Int this case the Pentax + 90 Macro really played to strength, so Lloyd says the results are better than what would be possible with FF 135.
This is no great surprise, as the sensor is larger and the base technology is similar. Obviously the 90/2.8 ED Macro is a good lens, albeit a bit expensive, I guess.
Best regards
Erik
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Hello,
CCD sensors will despair into obscurity like vinyl records, tape cassettes, CDs and film.
I for one think CMOS sensors are fantastic for my type of work.
Cheers
Simon
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Hi,
I would suggest that the benefits of CCD over CMOS mostly belong to the placebo category. There are some things to keep in mind, though:
- CCD sensors come from Kodak (now TrueSense ?) and DALSA both companies may have different CGA designs
- CCD is mostly medium format nowdays and comes with a proprietary raw developer with optimised profiles
- My guess is that it is possible to have MFD like rendition from a DSLR once profiles are tweaked
- Some users have found that the IQ-250 profiles in Capture one work better than the Nikon profiles for the Nikon D800. Capture One spending less effort on optimising colour for competing products?
When I am shooting my P45+ and Sony Alpha 99 I see very little difference after making all things equal. Using a grey card for white balance and adjusting white point, black point and midtones similarly.
The difference I see is mainly in resolution, which is better on the P45+. Another difference is that the P45+ has excessive color aliasing when processed in Lightroom but much less when processed in C1 (Capture One). So that round goes to capture one.
Of course, I do realise that my Sony Alpha 99 is vintage 2013 and the P45+ is vintage 2007, but I am also shooting a vintage 2009 Sony Alpha 900. And you can still buy 3-5 brand new Sony Alpha 99s for the price of a used P45+.
But, the resolution advantage of the P45+ is there, and 3-5 Alphas don't take better pictures than a single one.
Best regards
Erik
Still waiting for someone -- anyone -- to suggest an in-principle basis for any claimed benefit of CCD over CMOS. All can play.
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Hello,
CCD sensors will despair into obscurity like vinyl records, tape cassettes, CDs and film.
I for one think CMOS sensors are fantastic for my type of work.
Cheers
Simon
Yo Simon! Nice card - if you say no Moiré, then I'll believe you :)
Edmund
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Hi Eronald,
Take my word no Moiré out of 658 images shot on the day. But then again it was shot on a crappy Nikon D800.
Well its Friday afternoon here in NZ so I’m off to have a beer or two enjoy your weekend.
Cheers
Simon
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Still waiting for someone -- anyone -- to suggest an in-principle basis for any claimed benefit of CCD over CMOS. All can play.
There isn't really, but its just that CMOS can jump through the high ISO hoop and CCD can't, so all the designers and marketers tune the CMOS cameras to go even higher in ISO at the expense of IQ at base. Mostly this is CFA differences, but probably also electronics and well lot's of other stuff. So while in theory they should be the same, in practice they aren't …. at least that's what my eyes tell me. YMMV.
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Hi,
With regard to the CFA differences I think they may be a myth, too.
But, if we look at CFA characteristics, most CFA-s have very steep gradient in the 590 nm range. Differences in steepness here may affect rendition of red/yellow/green. It could be that red sensivity in this area may be optimized for skin tones or chlorophyl. Steep curves may give excessive color separation. It seems that melatonin also has a steep gradient in that area, by the way.
There is a measure of the ability of a sensor to reproduce colour, called SMI. A perfect sensor has high SMI. DxO measures this. There is a tendency of SMI going down but with latest generation sensors it is generally higher with DSLRs than with MFD. Latest generation Phase One backs are pretty high but still below Sony Alphas.
I did measure deviations on an It-8 card. I wouldn't call it a scientific test exactly, but still pretty interesting. Both my Alpha 99 and my P45+ reproduced the IT-8 well. The Alpha 99 with Lightroom was closest, but P45+ with Capture One was quite close. The 131225 profile mentioned is a DCP profile genarated by Adobe DNG Profile Editor based on a color checker exposure.
More reading:
http://echophoto.dnsalias.net/ekr/index.php/photoarticles/79-p45-colour-rendition?start=3
This can of course be called pseudo science…
Best regards
Erik
Still waiting for someone -- anyone -- to suggest an in-principle basis for any claimed benefit of CCD over CMOS. All can play.
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A 400 px wide screen capture hardly does justice to either image, but the main difference appears to be color balance. Certainly microcontrast and sharpness would not be faithfully reproduced in the screen capture. A simple MatchColors in Photoshop with the Pentax image ase the target removes many of the differences.
Bill
About the time the newer Leica S body was introduced, I did a shootout/comparison between the Pentax 645D, Leica S and Leica S2 body. All were at base ISO, shot Raw and the pair of lenses I selected were the two manufacturers 120 macro's. Both focal length were matched and both were considered at the time, the best or near best lens each manufacturer offered. Shots were taken under studio lighting at fairly close range and some additional comparitive shots outdoors at infinity. It was obvious the Pentax lens was optimized for closer distances and did go down to 1:1, whereas the 1:2 Leica macro faired better as a general purpose lens. It not going beyond 1:2 may have something to do with this.
I'm in the process of moving and the hard drives with all the images are currently packed away, otherwise I'd post some matched pairs. My general feeling was at closer range, the performance of these three cameras was extremely close and output response in terms of color and perceived detail was neck and neck. The similarities of color/depth may be in part due to all three being CCD based. Of course this is debatable.
At infinity distance, the Pentax macro was weak(er) along the sides and corners of the frame and this was obvious, although again under nature lighting, color response was remarkably similar.
One very noticeable issue with both Leica bodies was constant AF hunting at close range and lock-on was hard to achieve. The Pentax is this test performed admirably and locked-on focus with relative ease.
I mention all this in light of the posted pair of images posted in this thread. Thanks!
Dave
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Hi,
Thanks for your observations and effort.
The cameras you mention all use same generation Kodak sensors, so the sensors are extremely closely related.
Leica is know to have very good lenses, and the Leica S lenses are the reference Lloyd Chamers compares to.
Best regards
Erik
About the time the newer Leica S body was introduced, I did a shootout/comparison between the Pentax 645D, Leica S and Leica S2 body. All were at base ISO, shot Raw and the pair of lenses I selected were the two manufacturers 120 macro's. Both focal length were matched and both were considered at the time, the best or near best lens each manufacturer offered. Shots were taken under studio lighting at fairly close range and some additional comparitive shots outdoors at infinity. It was obvious the Pentax lens was optimized for closer distances and did go down to 1:1, whereas the 1:2 Leica macro faired better as a general purpose lens. It not going beyond 1:2 may have something to do with this.
I'm in the process of moving and the hard drives with all the images are currently packed away, otherwise I'd post some matched pairs. My general feeling was at closer range, the performance of these three cameras was extremely close and output response in terms of color and perceived detail was neck and neck. The similarities of color/depth may be in part due to all three being CCD based. Of course this is debatable.
At infinity distance, the Pentax macro was weak(er) along the sides and corners of the frame and this was obvious, although again under nature lighting, color response was remarkably similar.
One very noticeable issue with both Leica bodies was constant AF hunting at close range and lock-on was hard to achieve. The Pentax is this test performed admirably and locked-on focus with relative ease.
I mention all this in light of the posted pair of images posted in this thread. Thanks!
Dave
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Hi Eronald,
Take my word no Moiré out of 658 images shot on the day. But then again it was shot on a crappy Nikon D800.
Well its Friday afternoon here in NZ so I’m off to have a beer or two enjoy your weekend.
Cheers
Simon
Simon,
Nice job, good light, clean pics - don't get in too much weekend trouble :)
Edmund
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Still waiting for someone -- anyone -- to suggest an in-principle basis for any claimed benefit of CCD over CMOS. All can play.
I think we're all waiting for images, so we know what to explain away :)
Edmund
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Peeps should use what they want.
I think the Pentax file looks good and is kind of muted pastel (from what I've seen) but that doesn't mean much until you get into post work.
I just think people get too weirded out on this stuff.
I was looking for an extra evf bomb for one of my RED's last week, did a search and the internet was full of equipment forums where people were just pissing and moaning about each other's opinion.
I'll bet you 99% of the responses were hearsay but they were all having a go at each other, or dissing some equipment company that they were sure had "done them wrong".
What does it matter as long as you use the equipment you want to use and the photograph is worthwhile.
Personally I love using my S2, but I've shot stuff I like with it which goes a long way to me liking a camera.
I never would expect anyone else to agree, but don't know why that matters.
What does matter to me is I want all equipment companies to do well. I hope Pentax knocks it out of the park, same with Phase/leaf, Blad and Leica.
Good, profitable pro cameras are good for our industry and lately we have a lot of pretty cool choices
To me, I see a difference in all cameras, cmos or ccd, new to old, 35mm to 645 and some work to my style easier, some more difficult, but it's all good when you think about it.
IMO
BC
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Hi BC,
There is also the question of value.
For many users value matters a lot. Questions like:
- Want MF image quality, does the Pentax deliver it at an affordable price?
- The Pentax 25/4 mm lens costs as much alone as a DSLR and an excellent Zeiss 21/2.8 lens? Does it deliver an image quality motivating the difference.
- The Pentax 645Z is pretty similar in specs to the Leica S, and is said to have good high ISO image quality, can it deliver on image detail?
Questions like this are in my view quite valid. Not for the customer looking for the best stuff money can buy, but for anyone wanting to spend their money wisely.
The other side of the coin is that almost any equipment may be good enough. Personally, I feel that many of my best pictures were made with a 12 MP camera in 2008. Since that I have grown to 24 and 39 MP, but I don't think gears have improved my pictures. Essentially, 12 MP APS-C is good enough for most of the images I make. More pixels may be helpful for large prints, but I seldom print larger than A2.
The impression I have from Lloyds testing right now is that:
- The Pentax 645Z can deliver great image quality with the right lenses
- Even the best lenses are not as good as the Leica S lenses
- The Pentax 645Z has good image quality at high ISOs
Of course, it can be said that it is best to make your own tests, but it is not that simple. It takes some time and experience to find out about stuff. Renting stuff like MFD is not trivial for an amateur, like me. You need to have a company, insurance cover and a lot of stuff.
Just to mention, I have been shooting MFD for something like a year. After a year of use I still cannot say what I feel about my equipment. I enjoy shooting it, but I don't know about the results. I see the resolution advantage, but I may find it not so significant as I can see the differences in analytical viewing but not in actual prints. I also have that nagging feeling that few of my MF images are that great. Thriving for perfection may miss some great shots.
Using zooms gives a great advantage for composition. With a limited set of fixed focals I get more into cropping and stitching, so taking pictures is more engineering with MF and more dependent on post processing.
Many aspects…
My take is that it is great news that Pentax makes an affordable MF camera with a modern sensor, but I don't know if it is a good buy compared to affordable DSLR camera. Lloyd's initial reporting indicated it may not be a good buy, but in his later reporting he is more positive.
Best regards
Erik
Peeps should use what they want.
I think the Pentax file looks good and is kind of muted pastel (from what I've seen) but that doesn't mean much until you get into post work.
I just think people get too weirded out on this stuff.
I was looking for an extra evf bomb for one of my RED's last week, did a search and the internet was full of equipment forums where people were just pissing and moaning about each other's opinion.
I'll bet you 99% of the responses were hearsay but they were all having a go at each other.
What does it matter as long as you use the equipment you want to use and the photograph is worthwhile.
To me, I see a difference in all cameras, cmos or ccd and some correct to my style easier, some more difficult, but it's all good when you think about it.
IMO
BC
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.................................snip............................
There is also the question of value.
.................................snip............................
Using zooms gives a great advantage for composition. With a limited set of fixed focals I get more into cropping and stitching, so taking pictures is more engineering with MF and more dependent on post processing.
Many aspects…
My take is that it is great news that Pentax makes an affordable MF camera with a modern sensor, but I don't know if it is a good buy compared to affordable DSLR camera. Lloyd's initial reporting indicated it may not be a good buy, but in his later reporting he is more positive.
Best regards
Erik
Erik, cool, but this is what I mean.
What you want like microcontrast (I really don't know what that term means . . . seriously) and zooms isn't on my list, but I do respect that it's a feature you want and that's great.
What I find strange is so many people have a baseball bat out for the other opinion (Not You, just it seems on some forums in general, though this one is pretty good).
It's like when people talk about RED. No camera other than Leica seems to draw out so much "passion" both + and - as those two companies which is kind of strange.
To me they're great, though we had some learning curve early on, RED broke the mold and their cameras really have more than improved our work, they've just been a tremendous asset to our studios.
But it seems like RED has huge fan boys or huge haters and either one I don't get.
I'm realistic about my REDs. They were expensive (not so much today) but they opened the market up for 4k raw cameras and motivated other companies to follow suit.
I think that's great.
It's funny I was on a stage in west hollywood and went outside as we were prepping to go home. I started talking to this DP that does commerce and he was just moaning about the REDs. I asked him what he didn't like and he really couldn't say, other than he just didn't, but I looked at his comp reel on my mobile and asked him what was shot with what and 85% of all the non film work was with a R1 or Epic, so he might not like them but he's using them.
I'm with you though I think the Pentax is great because of price and it opens up a different world for medium format. Will it replace Phase/Leaf/Leica/Blad?
I dunno, I hope not because I assume all of those companies fill a slot and keep things moving forward.
Anyway, thanks for the reply.
IMO
BC
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My take is that it is great news that Pentax makes an affordable MF camera with a modern sensor, but I don't know if it is a good buy compared to affordable DSLR camera. Lloyd's initial reporting indicated it may not be a good buy, but in his later reporting he is more positive.
Best regards
Erik
This has been beaten to death in this and other forums. The answer is always the same. No, MF Digital, specially New Leica, PhaseOne and Hasselblad gear is NOT a good value if you want the best image quality for your dollar. The 645Z is a better value but still not a great value compared to say a D810.
Can you get better image quality with some of the MF Digital systems? Absolutely. Can you get different results and a very different shooting and working experience with a MF Digital System? Of course.
But if you are interested in the best image quality (in general, engineering/measurable terms) for your $ then the best 35mm DSLR systems are unbeatable.
If you want something different, then MF Digital offers many many options from integrated SLR systems like the Leica S and 645Z, semi-integrated systems like the PhaseOne DF+ / back combination to tech cameras like the ARCA RM3Di to cameras like the ALPA FPS that can combine SLR lenses with a modular tech style system. Some of us have one digital back and several setups for it.
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BC,
Thanks for responding. The main reason I started this thread was really to inform about Lloyds tests and also give some indications about his findings.
An interesting point is that Lloyd liked the Leica S2 when he tested it. My impression was that he considered buying it himself. I would not buy the Leica S, as it is beyond my means, but it seems to be an attractive camera to me.
I was interested in Pentax 645D, I was not far from buying one a couple of times. I have less interest in Pentax now, as I feel there are a lot of interesting developments on smaller formats. I am shooting a lot with my Hasselblad 555/P45+ combo now, it is fun to use it. Clearly I wouldn't buy it again, but I enjoy it as it is. I also have five lenses for the "Blad" and the availability of affordable lenses was the main reason I went with the "Blad".
Best regards
Erik
Erik, cool, but this is what I mean.
What you want like microcontrast (I really don't know what that term means . . . seriously) and zooms isn't on my list, but I do respect that it's a feature you want and that's great.
What I find strange is so many people have a baseball bat out for the other opinion (Not You, just it seems on some forums in general, though this one is pretty good).
It's like when people talk about RED. No camera other than Leica seems to draw out so much "passion" both + and - as those two companies which is kind of strange.
To me they're great, though we had some learning curve early on, RED broke the mold and their cameras really have more than improved our work, they've just been a tremendous asset to our studios.
But it seems like RED has huge fan boys or huge haters and either one I don't get.
I'm realistic about my REDs. They were expensive (not so much today) but they opened the market up for 4k raw cameras and motivated other companies to follow suit.
I think that's great.
It's funny I was on a stage in west hollywood and went outside as we were prepping to go home. I started talking to this DP that does commerce and he was just moaning about the REDs. I asked him what he didn't like and he really couldn't say, other than he just didn't, but I looked at his comp reel on my mobile and asked him what was shot with what and 85% of all the non film work was with a R1 or Epic, so he might not like them but he's using them.
I'm with you though I think the Pentax is great because of price and it opens up a different world for medium format. Will it replace Phase/Leaf/Leica/Blad?
I dunno, I hope not because I assume all of those companies fill a slot and keep things moving forward.
Anyway, thanks for the reply.
IMO
BC
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I am shooting a lot with my Hasselblad 555/P45+ combo now, it is fun to use it. Clearly I wouldn't buy it again, but I enjoy it as it is.
This is pretty much how I feel about the 645D. And how I felt about the 645Nii film body a decade or so ago. So we'll need a whole new imaging technology before I make any further MF purchases. :D
Since reading Ming Thein's review of the 645Z I've been using my D handheld a lot more. Seems to work pretty well for a hardly anything in focus approach to closeup work. The 120/4 macro is my new favorite among the 645 lenses. I'm surprised Pentax replaced it with a 90mm...working distance with the 120mm is just right.
-Dave-
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Since reading Ming Thein's review of the 645Z I've been using my D handheld a lot more. Seems to work pretty well for a hardly anything in focus approach to closeup work. The 120/4 macro is my new favorite among the 645 lenses. I'm surprised Pentax replaced it with a 90mm...working distance with the 120mm is just right.
-Dave-
Dave,
For a brief moment, I thought you had attached the cover shot of Wildi's famous book (one of my medium format bibles, back in the day):
(http://imageshack.com/a/img823/2449/12l5.jpg)
Over 25 years since that version of the book, and medium format is still being used effectively for that narrow-dof macro shot!
Ray
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Erik, that's Memorial Church at Leland Stanford Junior University. There is no Leland Stanford Senior University.
Jim
ageism, yet again :)
Edmund
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"...gears have..."
Gear has. ;-)
This has been beaten to death in this and other forums. The answer is always the same...
Your faith in the consistency of the answer seems a bit overdone. If you mean that "financial cost for measurement X is higher in some case A," then I suppose that it might be possible to approach some agreement on that very limited statement, especially if you constrain the measured parameter to one. (But, good luck with that!)
However, when it comes to value measured in ways that are non-monetary (differences in the way photographs will be used, differing ideas about the importance of one parameter versus another, issues of functional operation, how and what the photographer will photograph, etc.) the answer is far from "always the same."
Dan
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For a brief moment, I thought you had attached the cover shot of Wildi's famous book (one of my medium format bibles, back in the day):
(http://imageshack.com/a/img823/2449/12l5.jpg)
Over 25 years since that version of the book, and medium format is still being used effectively for that narrow-dof macro shot!
My dad had that book! (Which means I probably have it hidden away on a bookshelf...) Dagnamit, I'm a plagiarist. ;)
-Dave-
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Thanks for correction…
Regarding value, the Pentax 645 may be a game changer.
The main attraction is the price, of course. But it is also interesting that for the first time we have an MF camera that beats the DSLR competition on home ground, like high ISO, low readout noise fast multipoint AF. Live view and live view AF. The camera is weatherproofed. So it is something new in MF.
On the other hand, it is a very small MF, with a crop factor of 1.3, which means that the IQ-260 and the IQ-280 have almost twice the sensor area. On the other hand, Pentax can optimise it's lenses for the smaller sensor size. So, the small size may be an advantage.
Obviously, the Pentax is no competition for technical camera shooters using T&S facilities. Also, it cannot deliver 80 MP like the IQ-280.
Personally, I think it is interesting stuff.
Best regards
Erik
Gear has. ;-)
Your faith in the consistency of the answer seems a bit overdone. If you mean that "financial cost for measurement X is higher in some case A," then I suppose that it might be possible to approach some agreement on that very limited statement, especially if you constrain the measured parameter to one. (But, good luck with that!)
However, when it comes to value measured in ways that are non-monetary (differences in the way photographs will be used, differing ideas about the importance of one parameter versus another, issues of functional operation, how and what the photographer will photograph, etc.) the answer is far from "always the same."
Dan
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Why is this thread still alive?
Edmund
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If the Pentax had a wide range of affordable (for MF, that means about half the price of PhaseOne/Schneider and Hasselblad H mount lenses) and sensor size optimised lenses then it would be no question a much more appealing choice. As it is now it is a body looking for lenses. Not that there are none available, of course there are some nice lenses out there for it but the D810 has a huge amount of lens options (same with the A7R) and the same can be said when talking about a Digital Back. As it stands now there are no wide angle tilt/shift options for the Pentax and the wide angle options are limited. The Pentax 25mm is overpriced and so is the 90.
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Lloyd Chambers tests for sharpness and resolution. I had an Uncle long ago that used medium format film cameras to take family pictures (our family, not his own, he was divorced and childless) He would enlarge to 11x14 in his home darkroom and show them to us, his favorite feature of the photograph was its sharpness. He would also take occasional photo trips in which he photographed his favorite subject----sharp things.
If you are looking to take sharp pictures of bristlecone pines or of bicycles in your garage, Lloyd's your guy and you need look no further. My uncle would've loved him.
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Hi,
Lloyd Chambers figured that P 645Z may have some shutter related vibration. He has found that although the shutter is well dampened there is some measurable loss of sharpness due to vibration at certain shutter speeds, at least using the 90 mm macro lens.
This would not be obvious just visible like a loss of sharpness.
Best regards
Erik Kaffehr
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has somebody looked at the Mamiya mirror/shutter recoil?
all FP shutter cams are going to vibrate.
e.
Hi,
Lloyd Chambers figured that P 645Z may have some shutter related vibration. He has found that although the shutter is well dampened there is some measurable loss of sharpness due to vibration at certain shutter speeds, at least using the 90 mm macro lens.
This would not be obvious just visible like a loss of sharpness.
Best regards
Erik Kaffehr
-
Hi,
Yes, Michael Reichmann reported on the Phase One camera having problems with long lenses. There are also some reports on Alpha FPS, but let's say they are not confirmed.
So, the problem is not unique to the A7r and the Pentax 645. Personally, I have seen that problem on Pentax 67 in the film times.
Jim Kasson has investigated the problem to some depth, and my impression that he found it is an issue on the A7r with a couple of lenses he tested. Jim also investigated shutter related vibrations A7 with electronic first curtain and it was a non issue.
What both Jim and Lloyd Chambers found on the A7r that shutter vibration by and large eliminates the 36 MP to 24 MP advantage of the A7r when both cameras are mounted on a steady tripod using a stead head. Joseph Holmes found that adding an adequate weight under the camera can eliminate the vibrations. Lloyd made it simple, he found that mounting a flash on top of the cameras makes a decent job.
One interesting note is that Jim also checked shutter vibrations on the D800E, that camera had very little vibrations. The newer D810 has electronic first curtain, which neither the A7r or the P645Z have.
The loss of resolution caused by shutter related vibrations is normally small, measurable but really visible. I don't think it would be visible in an A2 size print (which is about maximum size for desktop printers). It could be argued that if you don't see a difference in A2 size print, the issue may be esoteric, but my feeling is that much of the discussion about MFD and CMOS/CCD etc is into esoterics anyway.
Best regards
Erik
has somebody looked at the Mamiya mirror/shutter recoil?
all FP shutter cams are going to vibrate.
e.
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I guess it all depends who is buying.
For me, the P645Z allows me to use all my existing lenses with significantly higher shutter speed, which makes a difference for both telephoto and macro. It also allows me to continue to use some of my wonderful old soft focus lenses, which simply don't work well in the 35mm range. I also have some unique macro lenses, which make more sense on the P645Z than on the Nikon. I don't buy the concerns about the 25mm at all, as this lens should not be taken on its own, but rather as the completion of an extraordinary system into the wide angle range. And for that purpose it's certainly an excellent lens.
The Nikon D800/800e has some strange autofocus issues which certainly would be a turnoff for me. On the upside, it might make sense to get a D810 if you are a new buyer as Nikon is upgrading their lens stable and as 35mm FF has many advantages when it comes to telephoto and extreme wide angle designs.
The Sony a7r is another option, but I would be thrown off by the shutter vibration issues. I also don't like the viewfinder and as of right now, there are only system specific lenses available, some good, others with varying quality. The telephoto range is disappointing. I'd like to get a a7r with electronic first curtain shutter and improved viewfinder to adapt to my old manual focus lenses though, but that's another chapter.
Personally, I am waiting to hear what Canon will come up with for this year's photokina and the months thereafter. They have turned their 5diii into an excellent body and they have been suspiciously quiet in the sensor department. I am convinced they have something up their sleeves that will suddenly turn their remarkable lens program with shift lenses and great telephoto options into a clear winner.
The Pentax has many advantages over the other medium format systems: price when it comes to Leica and Phase and a remarkable level of integration and automation when it comes to Phase and Rollei/DHW. I for once would hope that DHW finds someone to stick that new sensor in some sort of a box that can be fitted on the Hy6. Perhaps photokina will tell us more. In the meantime and for me, the P645Z is the cat's pajamas of the medium format world.
-
Lloyd Chambers figured that P 645Z may have some shutter related vibration.
Erik,
No offense but I trust people who actually use the camera a lot more than Lloyd Chambers.
If Michael eg. says that he has used the A7r for 8 months without noticing shutter vibration then that is sufficient for me…
Whatever the opinion of Mr Chambers may be…
Joris.
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Erik,
No offense but I trust people who actually use the camera a lot more than Lloyd Chambers.
If Michael eg. says that he has used the A7r for 8 months without noticing shutter vibration then that is sufficient for me…
Whatever the opinion of Mr Chambers may be…
Joris.
i wonder how much shutteration there is if you crank the P up to 1600 Iso in daylight
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Hi Edmund,
Can you explain a bit?
Anyway, what I see is that the shutter vibration related issues are not very visible, so I guess that most observers simply miss them. On the other hand, if we spend significant money on a high res camera and on the very best lenses I guess we should look into all issues reducing sharpness.
The shutter related vibration is noticeable mostly at around 1/20 - 1/40 seconds and up to 1/125. I normally shoot base ISO so I often get into that range when not shooting in full sunlight.
I normally shoot base ISO on all my cameras. The Sony's have little readout noise, but using low ISO minimises shot noise.
Best regards
Erik
i wonder how much shutteration there is if you crank the P up to 1600 Iso in daylight
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I received a mailing from a major Japanese photo equipment retailer over the weekend.
In that document they listed the Pentax 25mm f4 as being out of production.
Cheers,
Bernard
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Interesting... Why?
BR Erik
I received a mailing from a major Japanese photo equipment retailer over the weekend.
In that document they listed the Pentax 25mm f4 as being out of production.
Cheers,
Bernard
-
Hi,
Michael doesn't shoot test targets.
The A7r definitively has shutter related vibrations. Jim Kasson has analysed it truly. Sorry, in this case you are in a fact denial mode.
The reason Michael doesn't see the shutter vibrations may be:
- The image is good enough, although degraded by vibrations. It should be at the 24 MP level
- He is shooting higher ISO so he avoids the 1/15 - 1/125 range
- He is shooting handheld, in which case body adds mass and shutter times tend to be short
- He doesn't print larger than A2, I would think A1 size may show some differences
But, as the issue can be measured, it is obviously there. That said, it needs two images of test charts or subjects with very fine detail viewed at actual pixels one image on top of the other to see the difference.
Now, you may say, why care if you cannot se it? Good point. On the other hand, why pay for it if it isn't there?
Note also that this is strictly a tripod shooting issue limited to a range of shutter speeds, in all probability.
Here are two images from Jim Kasson's testing: http://blog.kasson.com/?m=201401
First, a flash illuminated image, that is reference. Second 1/80s with camera vertically mounted using an L-bracket. This is worst case.
(http://blog.kasson.com/wp-content/uploads/2014/01/weight-strobe.jpg)(http://blog.kasson.com/wp-content/uploads/2014/01/weight-60.jpg)
Best regards
Erik
Erik,
No offense but I trust people who actually use the camera a lot more than Lloyd Chambers.
If Michael eg. says that he has used the A7r for 8 months without noticing shutter vibration then that is sufficient for me…
Whatever the opinion of Mr Chambers may be…
Joris.
-
Erik,
Obviously, if you can crank the ISO up over 400 or 800 with no problems, then in daylight you will be shooting well above 1/125 and you will never see the vibration issues.
Studio shooters with studio flash also shouldn't see this problem unless there is a lot of ambient.
I think this one issue you really have to look for, or be working with an ISO 50 mentality - which in fact is what CCD users will be doing before they realize that CMOS has arrived ...
Edmund
Hi Edmund,
Can you explain a bit?
Anyway, what I see is that the shutter vibration related issues are not very visible, so I guess that most observers simply miss them. On the other hand, if we spend significant money on a high res camera and on the very best lenses I guess we should look into all issues reducing sharpness.
The shutter related vibration is noticeable mostly at around 1/20 - 1/40 seconds and up to 1/125. I normally shoot base ISO so I often get into that range when not shooting in full sunlight.
I normally shoot base ISO on all my cameras. The Sony's have little readout noise, but using low ISO minimises shot noise.
Best regards
Erik
-
I received a mailing from a major Japanese photo equipment retailer over the weekend.
In that document they listed the Pentax 25mm f4 as being out of production.
Interesting. Bernard, can you quote the full lens model from that mailing, if they gave it? As you may know, Pentax produced two versions of the 645 25mm f/4 lens. The first was designated D-FA, but it was quickly followed by one designated DA. It was a redesign for which I never saw a particular explanation, but as I understand it the DA was the one available outside of Japan while the D-FA remained in production but was available only in Japan. One pragmatic issue is that apparently the DA will vignette on a 645 full frame, so it appears to be purposely built for the smaller sensor of the 645D and 645Z cameras. That's consistent with the naming.
Curiously, the Ricoh USA web site lists the lens as DA, while the Ricoh Canada site lists it as D-FA. Though checking the product image of the Canadian lens, it clearly shows "DA", not "D-FA", so I believe their product listing is simply incorrect. (When I bought my 25mm a couple of years ago in Canada, the DA version is what I got.) However checking the Ricoh Japan web site I see both versions of the lens are no longer listed in the 645 lens lineup, though the D-FA 25mm still appears on the 645 lens road map (which hasn't been updated since Feb. 2014).
Given that the Pentax 645Z continues the roughly 44x33 mm sensor size and the source of the mailing you received, I would have surmised that if the 25mm was out of production, it was the D-FA version rather than both versions. I'd be very curious if Ricoh has indeed pulled this lens completely from production. They are due to introduce a new wide angle zoom soon, but I'm not sure I could see it replacing the need for the 25mm prime for some photographers.
-
Indeed, the Ricoh Japan site does list the D-FA 25mm f/4 as discontinued. But it makes no mention of the DA version; nor does the DA lens show up in the current lens list. So that's a bit confusing.
http://www.ricoh-imaging.co.jp/english/products/lens/index645_list_others.html
http://www.ricoh-imaging.co.jp/english/products/lens/index645_list.html
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B&H still lists the newer version of the Pentax 25mm as non-discontinued. They have it in stock @ 4.995.00
When I used the 645D, the 35mm FA was the lens I used most of the time. Mine was made in Vietnam, but an excellent version of the lens. I had used it for 4 year prior to the 645D on different Canon/Zork adapter combinations for stitching. I had read somewhere that Pentax was bringing the 35mm FA back, but that surprised me to have both a 25mm and 35mm in the same lineup.
Paul
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Ronald,
Unfortunately, I have that 50 ISO mentality. I shoot tripod and I feel that base ISO is the best choice, that is the best choice for me.
But, it is clearly possible to crank up ISO, even if increases midtone noise. The advantage of CMOS is mainly in readout noise, as I can see it, so it affect mostly the shadows.
With 50 ISO I am often shooting in the 1/30s to 1/125s range.
Best regards
Erik
Erik,
Obviously, if you can crank the ISO up over 400 or 800 with no problems, then in daylight you will be shooting well above 1/125 and you will never see the vibration issues.
Studio shooters with studio flash also shouldn't see this problem unless there is a lot of ambient.
I think this one issue you really have to look for, or be working with an ISO 50 mentality - which in fact is what CCD users will be doing before they realize that CMOS has arrived ...
Edmund
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Erik,
Not in denial mode and I don't have a stake in this as I don't own an A7r.
My point is that I don't like statements like: HE says it MAY have a problem.
Either you know precisely whether it has a problem and under which conditions, or you don't and then you shut up about it.
From what I have read there is nothing preventing the A7r from being an excellent camera when using it handheld, with the native 35 and 55mm FE lenses and using shutter speeds of 1/125 or shorter. Quite frankly that is what a lot of (if not most) people do.
I personally have no interest in an A7r but the A7s does sound very appealing to me.
Best, Joris.
Hi,
Michael doesn't shoot test targets.
The A7r definitively has shutter related vibrations. Jim Kasson has analysed it truly. Sorry, in this case you are in a fact denial mode.
The reason Michael doesn't see the shutter vibrations may be:
- The image is good enough, although degraded by vibrations. It should be at the 24 MP level
- He is shooting higher ISO so he avoids the 1/15 - 1/125 range
- He is shooting handheld, in which case body adds mass and shutter times tend to be short
- He doesn't print larger than A2, I would think A1 size may show some differences
But, as the issue can be measured, it is obviously there. That said, it needs two images of test charts or subjects with very fine detail viewed at actual pixels one image on top of the other to see the difference.
Now, you may say, why care if you cannot se it? Good point. On the other hand, why pay for it if it isn't there?
Note also that this is strictly a tripod shooting issue limited to a range of shutter speeds, in all probability.
Here are two images from Jim Kasson's testing: http://blog.kasson.com/?m=201401
First, a flash illuminated image, that is reference. Second 1/80s with camera vertically mounted using an L-bracket. This is worst case.
(http://blog.kasson.com/wp-content/uploads/2014/01/weight-strobe.jpg)(http://blog.kasson.com/wp-content/uploads/2014/01/weight-60.jpg)
Best regards
Erik
-
My point is that I don't like statements like: HE says it MAY have a problem.
Either you know precisely whether it has a problem and under which conditions, or you don't and then you shut up about it.
From what I have read there is nothing preventing the A7r from being an excellent camera when using it handheld, with the native 35 and 55mm FE lenses and using shutter speeds of 1/125 or shorter. Quite frankly that is what a lot of (if not most) people do.
I may be able to shed some light on the a7R's shutter vibration and its effect on handheld image sharpness.
A description of MTF testing of handheld photos of slanted edge targets (http://blog.kasson.com/?p=5166).
Results of handheld testing of the a7 and a7R with the Zony 55mm f/1.8 Sonnar FE lens. (http://blog.kasson.com/?p=5175) The vertical axis on the plots is proportional to cycles per picture height. I didn't figure that out until later.
Comparing the a7R to the Nikon 800E (no mirror lockup) handheld. (http://blog.kasson.com/?p=5188)
Musings on the difficulty of testing handheld cameras. (http://blog.kasson.com/?p=5197) After doing HH testing for a while, I was so happy to get back to my tripod.
A semi-rigorous discussion of the intellectual underpinnings on hand held testing. (http://blog.kasson.com/?p=5230)
Real-world images (not test targets) from the a7 and a7R and the Zony 55 under similar (as close as I could get to identical) circumstances. (http://blog.kasson.com/?p=5267)
FWIW...
Jim
-
Not in denial mode and I don't have a stake in this as I don't own an A7r.
My point is that I don't like statements like: HE says it MAY have a problem.
Either you know precisely whether it has a problem and under which conditions, or you don't and then you shut up about it.
After reading about the A7r shutter vibration thing for awhile I decided to see if I could induce it with my own sample of the camera & various lenses. Here's what I came up with:
– Handheld use: non-issue.
– Tripod use (camera mounted): non-issue.
– Tripod use (lens mounted): slight degradation with longer lenses (300mm & up) visible on-screen at high mag, not noticeable in 14x21" prints (as large as I go).
In the third case I've found that sticking my heaviest flash unit, a Contax TLA–360, on the camera lessens and maybe eliminates the degradation. In fact it was doing a comparison with & without the flash that allowed me to see the issue, slight as it is, in the first place. So I now mount the flash to add mass whenever I use the A7r on a tripod. I tend not to be perfectionist about this stuff, but OTOH I don't mind an easy solution to an issue that may not be visible in real-world conditions but that nonetheless I know exists. :)
-Dave-
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Erik,
The Sony probably has a base ISO of around 200 - even the old CCD Leica S2 has an official base ISO at 160. Technology has improved, and also these are microlensed sensors, which gives them a stop more. So where you would be shooting at 1/50 these cameras would be at 1/200 native. I'm not saying the vibration issues don't exist, just they are not very relevant to handheld and actually all daylight landscape users, who in the worst case will set a 200 ISO native camera to 400, lose 1 stop DR on a record-breaking DR camera, and still shoot 1/400 @ F8 on an overcast day.
Edmund
Ronald,
Unfortunately, I have that 50 ISO mentality. I shoot tripod and I feel that base ISO is the best choice, that is the best choice for me.
But, it is clearly possible to crank up ISO, even if increases midtone noise. The advantage of CMOS is mainly in readout noise, as I can see it, so it affect mostly the shadows.
With 50 ISO I am often shooting in the 1/30s to 1/125s range.
Best regards
Erik
-
The Exmor in the D810 has a base ISO of 64. The Exmors that came before it had a base ISO of 100.
-
I received a mailing from a major Japanese photo equipment retailer over the weekend.
In that document they listed the Pentax 25mm f4 as being out of production.
Cheers,
Bernard
Bernard,
This comes as something of a surprise given the excitement the Z has generated. I assume the decision is based on sales, but seems premature since sales generated by the Z have yet to be seen. As much as I would like to have that lens, the price and size have made me and many other D users hesitate (stitching with the excellent 35mm isn't too bad and a lot less expensive); I'm waiting for the WA zoom. Maybe as expensive and heavy, but more versatile.
Tom
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Hi,
It seems that there are two different 25/4 lenses involved, according to some other posting.
Best regards
Erik
Bernard,
This comes as something of a surprise given the excitement the Z has generated. I assume the decision is based on sales, but seems premature since sales generated by the Z have yet to be seen. As much as I would like to have that lens, the price and size have made me and many other D users hesitate (stitching with the excellent 35mm isn't too bad and a lot less expensive); I'm waiting for the WA zoom. Maybe as expensive and heavy, but more versatile.
Tom
-
Hi,
It seems that there are two different 25/4 lenses involved, according to some other posting.
Best regards
Erik
Yes, for some unexplained reason Pentax had two versions of this lens but, as the link posted by Royce above indicates, neither is listed on the current lens map. The other discontinued lens that causes me some surprise is the 600mm A*. Yes it's expensive, but even as a MF lens it's a gem; I'm sure there aren't many and they cost a fortune to make. Maybe Ricoh is more practical than the old (pre-Hoya) Pentax.
Tom
http://www.ricoh-imaging.co.jp/english/products/lens/index645_list.html
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Hi,
A few comments.
In general I presume that folks buy the A7r because of the resolution. Also, it seems that many quite a few users buy A7r as a an high resolution high DR option to Canon. So I presume that resolution is at premium for many users.
I would agree that the vibration is not much a problem handheld shooting, as shorter times are generally used handheld. Also, DSLRs have mirror vibration that is usually significant.
Where the effect is measureable is:
- on tripod
- time range 1/4 - 1/250 or so
The vibration is enough to measurable degrade the image. Probably not enough to cause visual degradation in A2 size prints. The amount image degradation depends a lot on pivot points, inertia of rotation, focal length and dampening.
The A7 does not have this problem using the EFC, so in many cases it may be the better choice.
Actually, I am mostly shooting tripod mounted, and I often shoot in the 1/15 - 1/60 range - always with MLU. So for me the shutter vibration is relevant.
Knowledge of the vibration issue may be helpful in reducing the problem, like increasing ISO to get into a less problematic shutter speed range.
I don’t own neither A7 nor A7r, but I may buy a later generation A# camera if they make them to my liking.
Best regards
Erik
After reading about the A7r shutter vibration thing for awhile I decided to see if I could induce it with my own sample of the camera & various lenses. Here's what I came up with:
– Handheld use: non-issue.
– Tripod use (camera mounted): non-issue.
– Tripod use (lens mounted): slight degradation with longer lenses (300mm & up) visible on-screen at high mag, not noticeable in 14x21" prints (as large as I go).
In the third case I've found that sticking my heaviest flash unit, a Contax TLA–360, on the camera lessens and maybe eliminates the degradation. In fact it was doing a comparison with & without the flash that allowed me to see the issue, slight as it is, in the first place. So I now mount the flash to add mass whenever I use the A7r on a tripod. I tend not to be perfectionist about this stuff, but OTOH I don't mind an easy solution to an issue that may not be visible in real-world conditions but that nonetheless I know exists. :)
-Dave-
-
Jim,
Thanks for chiming in.
I am most concerned about high resolution work on tripod. I assume that tripod is pretty necessary to make full use of the resolution, but i may be wrong.
Best regards
Erik
I may be able to shed some light on the a7R's shutter vibration and its effect on handheld image sharpness.
A description of MTF testing of handheld photos of slanted edge targets (http://blog.kasson.com/?p=5166).
Results of handheld testing of the a7 and a7R with the Zony 55mm f/1.8 Sonnar FE lens. (http://blog.kasson.com/?p=5175) The vertical axis on the plots is proportional to cycles per picture height. I didn't figure that out until later.
Comparing the a7R to the Nikon 800E (no mirror lockup) handheld. (http://blog.kasson.com/?p=5188)
Musings on the difficulty of testing handheld cameras. (http://blog.kasson.com/?p=5197) After doing HH testing for a while, I was so happy to get back to my tripod.
A semi-rigorous discussion of the intellectual underpinnings on hand held testing. (http://blog.kasson.com/?p=5230)
Real-world images (not test targets) from the a7 and a7R and the Zony 55 under similar (as close as I could get to identical) circumstances. (http://blog.kasson.com/?p=5267)
FWIW...
Jim
-
I am most concerned about high resolution work on tripod. I assume that tripod is pretty necessary to make full use of the resolution, but i may be wrong.
Erik, I'm going to make my response in the context of big, focal plane shutter, cameras in general, rather than the Sony a7R, which is a bit of a red herring on this thread, since it has a set of shutter characteristics that don't apply to any medium format camera. WRT the 645Z, Lloyd's charts indicate to me that the camera;s shutter shock is quite a bit lower than the a7R's, although the star target that Lloyd uses makes getting any quantitative data off the image impossible -- at least for me. As an aside the crosses on the ISO 12233 chart are much better for this.
Enough preamble. On to your point. I'm assuming that anyone buying a 645Z wants to use all 50 MP; otherwise, why not get a D8x0, have a big choice of lenses, and save a bundle? One non-vibrational impediment to using all those pixels is focusing. In doing handheld work with the ISO 12233 target and a slanted edge target for SFR analysis, I was totally flummoxed when working with manual focus lenses. I gave it up and had to go with AF lenses, which are thin on the ground for the alpha 7 line. The reason was that with manual focus slight movements of the camera between focusing and shutter release resulted in focus errors that totally swamped out the resolving power of the lens and the camera. This was a particular problem with the a7R, since focusing had to be done at taking aperture when handholding, but would be a problem with a DSLR, which would have the advantage of the ability to focus wide open, but the disadvantage of a much less precise way to judge focus than live view.
So, leaving vibration out of it, I think you need a tripod to consistently use all that resolution. Electronic flash and AF lenses might ameliorate this. BTW, a lot of studio electronic flash systems have fairly long (>1ms for t.1) flash durations at some or all power settings.
Let's consider vibration. If you're shooting the 645Z handheld, you don't want to hold it at arms length for any length of time. That means you can't use live view. You want to be able to accurately frame the shot. That means you can't use mirror lockup. So you're going to have to suffer mirror slap. That alone is going to make it hard to use all those 50 MP. Hassy has a programmable delay between mirror up and first curtain release that apparently helps. I don't know if Pentax does.
As an aside, one thing that helped with electronic flash pictures with the a7R should also help on the 645Z: use trailing curtain synch and a longish (1/25 was a good number for the a7R) shutter speed.
All that is a long-winded way of saying that I agree with you.
Jim
-
WRT the 645Z, Lloyd's charts indicate to me that the camera;s shutter shock is quite a bit lower than the a7R's, although the star target that Lloyd uses makes getting any quantitative data off the image impossible -- at least for me. As an aside the crosses on the ISO 12233 chart are much better for this.
Actually, most bi-tonal patterns are not suited for quantitative analysis. They only allow a quick visual impression, but aliasing artifacts and phase alignment of pattern and sensel grid will make such comparisons error prone. Slanted edges are very well usable, because they allow oversampling of sensor resolution, and their usual close to orthogonal orientation allows to easily distinguish between horizontal and vertical resolution.
[..] with manual focus slight movements of the camera between focusing and shutter release resulted in focus errors that totally swamped out the resolving power of the lens and the camera.
Yes, often under rated, defocus kills resolution pretty quickly, and the really critical DOF zone is thin (result of using a small COC).
So, leaving vibration out of it, I think you need a tripod to consistently use all that resolution. Electronic flash and AF lenses might ameliorate this. BTW, a lot of studio electronic flash systems have fairly long (>1ms for t.1) flash durations at some or all power settings.
Indeed.
Cheers,
Bart
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Actually, most bi-tonal patterns are not suited for quantitative analysis. They only allow a quick visual impression, but aliasing artifacts and phase alignment of pattern and sensel grid will make such comparisons error prone. Slanted edges are very well usable, because they allow oversampling of sensor resolution, and their usual close to orthogonal orientation allows to easily distinguish between horizontal and vertical resolution.
You're right as usual, Bart, but I was talking about rough visual interpretation, not machine analysis. I'm sure there are better targets thanISO 12233, but it has the advantage of ubiquity.
Jim
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Hi,
Reminds me of a test I made for mirror caused vibrations. I shot a series of 1/15s to 1/125s exposures using a 200 mm lens, long ago on 6MP DSLR:
1) Free hand with antishake
2) Tripod with antishake
3) Tripod without antishake
4) Tripod with MLU and no antishake
Visual examination of the images at actual pixels indicated all were equally good. Using Imatest on a slanted edge I found that cases 1-3 had about half the resolution compared to MLU. So I had actually reduced my 6 MP DSLR to a 1.5 MP DSLR without seeing the effect. Interestingly enough, once I have seen the Imatest results I could also see the difference on screen.
What I have learned from this is:
1) You often see what you expect hope to see
2) Vision can be trained
A few times I did comparisons between cameras having different resolutions in print. It is very tricky. First impression is often that I see very little difference, but I learn where the differences are. Once I know where to look it may be quite easy to see a difference.
The way Lloyd presents his test shots he has the images stacked and you can flip between the images using mouse roll over. It is quite illustrative.
Something I have observed is that it is hard to compare images side by side, much easier if one image is on top of another.
Anyway, the way I see it, if you look at two images of different quality and cannot tell them reliably apart, they are probably both good enough. What I also have seen is that differences tend to go away if processing is identical. Include a ColorChecker and adjust bright and dark patch to same density and use a grey patch for WB and much of the difference simply disappears.
Getting back to the Pentax, Lloyd Chambers have tested quite a few of the lenses and a few of them were excellent, most were not. But, most pictures I have seen from the Pentax 645D were pretty good. So I assume that most lenses are OK, or good enough.
Another example, stopping down to f/16 does reduce image quality significantly, but perceived sharpness is often quite OK at f/16 and much of the loss of edge contrast can be recovered in sharpening.
My conclusion is mainly that human vision can be quite forgiving, unless you cross some limit.
Another association: Measure with micrometer, mark with chalk and cut with axe.
Best regards
Erik
You're right as usual, Bart, but I was talking about rough visual interpretation, not machine analysis. I'm sure there are better targets thanISO 12233, but it has the advantage of ubiquity.
Jim