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Thread: IQ180 vs Up-Res A7R2

  1. #51
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    Re: IQ180 vs Up-Res A7R2

    Quote Originally Posted by gerald.d View Post
    If you're in a situation where you can stitch with the Sony, then you can also stitch with the IQ.
    Doesn't it depend on the lens being used - assuming we're talking about getting good results from shifting, rather than just being able to shift ?

    The question is: does the new type of sensor used in the Sony behave as badly as the one in the IQ180 with large shifts where the angle of light hitting the sensor at the edge of the IC is acute ?

    Since I've yet to hear anything about how it performs in such situations (and the BSI sensor design is predicted as behaving well with light striking it at an acute angle), I wouldn't reach that conclusion just yet.

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    Re: IQ180 vs Up-Res A7R2

    Quote Originally Posted by vjbelle View Post
    The image circle of even the 17mm TS-E is not as large as the Phase Sensor..... therefore vignetting occurs. I don't understand the allure of using 35mm lenses with the FPS as there is, IMHO, nothing to be gained over current cameras. The resulting file size remains the same, or smaller, because of the constriction of the image circle. Usually, if not almost always, the dedicated camera body for the given lens (Nikon, Canon, etc) has more than surpassed the electronics in the FPS and would be easier to use. I do think that the examples show just how far and fast Sensor technology is moving on.

    Victor
    The allure of using the 17mm TS-E on full frame MF with the FPS is that it gives you a field of view that is not possible with any other lens.

    It's not a matter of subjective humble opinion, but one of objective fact.

    And until the release of the 11-24, it gave you a field of view that was not possible on any other lens/sensor combination that has ever existed.

  3. #53
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    Re: IQ180 vs Up-Res A7R2

    Quote Originally Posted by f8orbust View Post
    Doesn't it depend on the lens being used - assuming we're talking about getting good results from shifting, rather than just being able to shift ?

    The question is: does the new type of sensor used in the Sony behave as badly as the one in the IQ180 with large shifts where the angle of light hitting the sensor at the edge of the IC is acute ?

    Since I've yet to hear anything about how it performs in such situations (and the BSI sensor design is predicted as behaving well with light striking it at an acute angle), I wouldn't reach that conclusion just yet.
    No. It is an irrelevant condition as you should be assuming equal angle of view. In both cases, you would go to a longer focal length lens for the shifted/stitched image which would perform better than a shorter one.

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    Re: IQ180 vs Up-Res A7R2

    Quote Originally Posted by f8orbust View Post
    Doesn't it depend on the lens being used - assuming we're talking about getting good results from shifting, rather than just being able to shift ?

    The question is: does the new type of sensor used in the Sony behave as badly as the one in the IQ180 with large shifts where the angle of light hitting the sensor at the edge of the IC is acute ?

    Since I've yet to hear anything about how it performs in such situations (and the BSI sensor design is predicted as behaving well with light striking it at an acute angle), I wouldn't reach that conclusion just yet.
    There are two possible scenarios here.

    If you're talking about shift-stitching to create an image with a wider field of view than is usually available from a given lens:sensor combination, then assuming you're utilising a good lens, the MF solution is going to be advantageous simply because you will always be able to capture in a single shot what the Sony solution would require multiple exposures with lens shifts to accomplish.

    And I'm sorry, but the IQ180 does NOT behave "badly" when paired with good lenses such as the Rodenstocks. Does the A7R2 perform well with these lenses? Bit of a moot point if you ask me - if you have to shift the sensor multiple times and take multiple exposures to get the same composition as a FF MF sensor is going to deliver with one exposure, just what are the circumstances in which it would be advantageous to do that?

    The second scenario (and actually, the one that is probably more relevant here, because the point raised was "By stitching the A7R-II surely yields more details than the IQ180."), is that what was being inferred was that by nodal stitching with the A7R2 you will get more detail than you would with the IQ180. Yes - of course that's an option. But if you're going to nodal stitch, then you can do so with the IQ180 as well. When it comes to nodal stitching, for the same number of exposures to deliver a set field of view, an 80MP MF back will always deliver more resolution than the A7R2.

    Kind regards,


    Gerald.
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    Re: IQ180 vs Up-Res A7R2

    Long exposures

    I mean and need only "long" exposures, not loooooong exposures like Void;-)

    Example: At a late sunset, just before the sun light completely disappears, I typically shoot with the IQ at ISO 35 f11 8s. That's about the maximum exposure time acc. my experience (using ACR) without deterioration of the file quality.

    At 20-60 seconds, the plain areas become to a certain extend grainy, the sharpness on pixel level is decreasing, more and more hot pixels show up, even with the dark exposure applied. (C1 handles this better than ACR)

    With the Sony A7RII I tested 30s at ISO 100 (with NR = dark frame ON), still can lift the exposure or the shadows enormously and get a very good result. 30s ISO 100 is 4 stops difference EV to 8s ISO 35, so that's a usable advantage for my application.

    Sample: Photography in near full darkness (crop), ISO 50, 30s, lifted 3 steps in ACR

    Click image for larger version. 

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    TSE 17 vignetting with IQ180

    W/o shift the TSE 17 image circle is "just" sufficient for the 54x40mm sensor, but my sample picture was with full 12mm shift on the long side, so you see what you get, still impressive IMO.

    TSE 17 12mm shift left + 12mm shift right + stitch on IQ180

    This gives a damn wide pano image with below 10mm 135 field of view and up to 12000 pixels width.

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    Re: IQ180 vs Up-Res A7R2

    Quote Originally Posted by chrismuc View Post
    I mainly got the A7RII to accompany my FPS-IQ180 set-up either for evening or night architecture shots where the higher base ISO and the cleaner files at longer exposure times of the Sony is a clear advantage to the PhaseOne back and for longer focal lengths.

    I did not have much time yet for direct comparison of the two systems but what I see is, that it's incredible which quality can be achieved by a 135 format sensor camera and a good lens today. But the camera needs sharp lenses;-) 4.5 um pixel size is really tiny and too much sharpening in post can add some "pseudo-random" structure to the plain areas of the picture (maybe due to the not-lossless compression of the Sony raw).

    Of course the size of the Sony + Metabones set-up is so nicely tiny, I was not longer used to carry around such a little camera.

    Attachment 94398
    Strange - I have exactly this outfit too! FPS, IQ180, A7R, metabones, etc.

    Am not a super wide user though, so no TSE for me - Mainly Otus on my A7R, and the Sony 55mm too. for walk around the 40mm Canon is super light & compact on EF adapter. (and ridiculously cheap!)

    I use a 50/60/90 on my FPS mostly. the 60 is very light and great angle of view, and its f4. Plus it nicely = the 40mm on A7R

    Still waiting for Phase/Sony next generation MF back to arrive with EVF outlet point, so I can use a viewfinder with live view focus/ peaking, then we have will truly have Mirrorless MF with the FPS. Can't wait.

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    Re: IQ180 vs Up-Res A7R2

    Quote Originally Posted by gerald.d View Post
    The allure of using the 17mm TS-E on full frame MF with the FPS is that it gives you a field of view that is not possible with any other lens.

    It's not a matter of subjective humble opinion, but one of objective fact.

    And until the release of the 11-24, it gave you a field of view that was not possible on any other lens/sensor combination that has ever existed.
    Unless I am missing something the FOV on the IQ180 - after croping out the vignetting - will be approximately the same as the FOV on the Sony A7rll and the pixel dimensions are approximately the same. If the FPS is the 'only' system available then I see your point..... but if it were me I would mount that lens on an A7rll.

    Victor

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    Re: IQ180 vs Up-Res A7R2

    Quote Originally Posted by gerald.d View Post
    If you're in a situation where you can stitch with the Sony, then you can also stitch with the IQ.

    It's simply not a valid argument.
    Exactly. The IQ180 combined with Rodenstock HR-W glass can produce a file that is just way above any 35mm or smaller format file. I have yet to see samples of the results when the A7RII is used with the HR-W's though.

    The Rodenstock HR-W lenses are just a cut above any other lens I have used, it is no contest. (Well, the Cine Leica Summilux-C lenses are another story, but I have yet to see one used for still photography. They look AMAZING on a RED or Alexxa camera though ).

    I get stunning results with the IQ160 and 40mm HR-W even when shifted a lot. I really do not wish for anything better in most landscape situations. The color gradations are rendered superbly.

    The new Sony looks very nice but the file compression seems an issue when pushing the files a lot, something that is a non issue with the PhaseOne backs and C1pro. The Nikon D810 at base iso (64) is the camera that mostly resembles medium format digital in quality (color and file pushability) not the A7R/A7RII.

    If Sony fixes via firmware the file compression then things might change but until then, there are better choices. I am sure it can be done and be offered as an option even if it sacrifices a lot of speed, something the landscapers care little about anyway.

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    Re: IQ180 vs Up-Res A7R2

    Quote Originally Posted by chrismuc View Post
    Long exposures


    TSE 17 vignetting with IQ180

    W/o shift the TSE 17 image circle is "just" sufficient for the 54x40mm sensor, but my sample picture was with full 12mm shift on the long side, so you see what you get, still impressive IMO.

    TSE 17 12mm shift left + 12mm shift right + stitch on IQ180

    This gives a damn wide pano image with below 10mm 135 field of view and up to 12000 pixels width.
    This may be stretching the limits of that lens to the extreme. It doesn't matter how many pixels are in the final stitched image but rather the quality of those pixels. Even with my longest lens on my STC I limit shifting to 10mm. If I need more than than then I resort to panning which many times will give better results (Architectural images being the exception). I have found that shifting beyond certain limits results in very disappointing images. YMMV.

    Victor

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    Re: IQ180 vs Up-Res A7R2

    Quote Originally Posted by chrismuc View Post
    Long exposures

    I mean and need only "long" exposures, not loooooong exposures like Void;-)

    Example: At a late sunset, just before the sun light completely disappears, I typically shoot with the IQ at ISO 35 f11 8s. That's about the maximum exposure time acc. my experience (using ACR) without deterioration of the file quality.

    At 20-60 seconds, the plain areas become to a certain extend grainy, the sharpness on pixel level is decreasing, more and more hot pixels show up, even with the dark exposure applied. (C1 handles this better than ACR)

    With the Sony A7RII I tested 30s at ISO 100 (with NR = dark frame ON), still can lift the exposure or the shadows enormously and get a very good result. 30s ISO 100 is 4 stops difference EV to 8s ISO 35, so that's a usable advantage for my application.
    Gerald insists that CCD is good enough for that area (post here). On the other hand, my experience with CCD agrees with your statement here. Would you be able to share RAW files in this area (i.e. long exposure but not too long) to see the shadow recoverability, for a comparison between the 80MP Dalsa and the A7R-II?

    Originally I speculated that in the 30 second territory the A7R-II could offer more details in the shadow than the IQ180, but now it appears that the A7R-II performs rather disappointing at 30 seconds when compared against its predecessor A7R.

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    Re: IQ180 vs Up-Res A7R2

    Quote Originally Posted by voidshatter View Post
    Gerald insists that CCD is good enough for that area (post here). On the other hand, my experience with CCD agrees with your statement here. Would you be able to share RAW files in this area (i.e. long exposure but not too long) to see the shadow recoverability, for a comparison between the 80MP Dalsa and the A7R-II?

    Originally I speculated that in the 30 second territory the A7R-II could offer more details in the shadow than the IQ180, but now it appears that the A7R-II performs rather disappointing at 30 seconds when compared against its predecessor A7R.
    No I don't.

    Stop deliberately conflating what I was discussing with a totally different subject.

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    Re: IQ180 vs Up-Res A7R2

    Quote Originally Posted by voidshatter View Post
    Gerald insists that CCD is good enough for that area (post here). On the other hand, my experience with CCD agrees with your statement here. Would you be able to share RAW files in this area (i.e. long exposure but not too long) to see the shadow recoverability, for a comparison between the 80MP Dalsa and the A7R-II?

    Originally I speculated that in the 30 second territory the A7R-II could offer more details in the shadow than the IQ180, but now it appears that the A7R-II performs rather disappointing at 30 seconds when compared against its predecessor A7R.
    I will do some comparison shots and post raws, just takes a few days because I am about to travel.
    But IMO one would have to compare for example

    Sony A7R-II at ISO 100 30s
    vs
    IQ180 at ISO 35 with 90s.

    And there the Sony will be sure better than the Phase. If using ISO 100 on the Phase (without 1.5 stop overexposure;-) , the sharpness on pixel level is already lower than at ISO 35, so I don't use it.

    Btw., I considered to get the original A7R to accompany my IQ but I very disliked the quality appearance of the camera body and the user interface, plus the shutter vibration topic. In all three regards the Mark II is a big improvement.

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    Re: IQ180 vs Up-Res A7R2

    Quote Originally Posted by vjbelle View Post
    Unless I am missing something the FOV on the IQ180 - after croping out the vignetting - will be approximately the same as the FOV on the Sony A7rll and the pixel dimensions are approximately the same. If the FPS is the 'only' system available then I see your point..... but if it were me I would mount that lens on an A7rll.

    Victor
    Yes. You are missing something rather obvious.

    With the lens centered, the image circle just about fills the IQ180 frame.

    Which is equivalent to the field of view of an 11mm lens on 35mm.

    As I said before. Until the introduction of the Canon 11-24, no other lens/sensor combination provided such a wide field of view.

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    Re: IQ180 vs Up-Res A7R2

    Hi,

    I have seen some reports indicating that vignetting and cross talk is much less with the BSI.

    Best regards
    Erik


    Quote Originally Posted by f8orbust View Post
    Doesn't it depend on the lens being used - assuming we're talking about getting good results from shifting, rather than just being able to shift ?

    The question is: does the new type of sensor used in the Sony behave as badly as the one in the IQ180 with large shifts where the angle of light hitting the sensor at the edge of the IC is acute ?

    Since I've yet to hear anything about how it performs in such situations (and the BSI sensor design is predicted as behaving well with light striking it at an acute angle), I wouldn't reach that conclusion just yet.

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    Re: IQ180 vs Up-Res A7R2

    Quote Originally Posted by Ken_R View Post
    The Rodenstock HR-W lenses are just a cut above any other lens I have used, it is no contest. (Well, the Cine Leica Summilux-C lenses are another story, but I have yet to see one used for still photography. They look AMAZING on a RED or Alexxa camera though ).
    I'll see if I can fix that

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    Re: IQ180 vs Up-Res A7R2

    Quote Originally Posted by gerald.d View Post
    And I'm sorry, but the IQ180 does NOT behave "badly" when paired with good lenses such as the Rodenstocks.
    Never said it did.

    I said performance is dependent on the lens being used. Just because all the latest R/S (RF) design lenses are good (however you define 'good') does not mean that all good lenses are R/S (RF) designs.

    It's been common knowledge pretty much from day one that the sensor in the IQ180 behaves badly when shifted with good lenses from Schneider (and no, a lens doesn't suddenly become 'bad' because it won't play ball with a particular sensor). Which is a shame, because the S/K WA designs (in particular) have large ICs that you might want to perform large shifts with.

    This is why the emerging BSI technology is important, since it promises to behave well with all lenses.

    Jim
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    Re: IQ180 vs Up-Res A7R2

    Quote Originally Posted by gerald.d View Post
    Yes. You are missing something rather obvious.

    With the lens centered, the image circle just about fills the IQ180 frame.

    Which is equivalent to the field of view of an 11mm lens on 35mm.

    As I said before. Until the introduction of the Canon 11-24, no other lens/sensor combination provided such a wide field of view.
    With the lens centered there is a lot, to me, of vignetting. Once that vignetting is cropped out the image is almost identical to the Sony image - other than format dimensions. If the vignetting is included to calculate FOV then, of course, the FOV is increased. BUT the vignetting has to be cropped out to get a usable image - at least for me. The first image is the lens centered on the FPS/IQ180. The second image is the cropped version. The third image is the Sony A7Rll with the same lens. What am I missing? If the lens is shifted on the IQ180 to eliminate vignetting the image becomes larger and field of view increases. BUT..... I can duplicate that with the Sony. Tell me what is gained?

    Victor
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    Re: IQ180 vs Up-Res A7R2

    Thanks for the links, they are informative.

    Best regards
    Erik



    Quote Originally Posted by voidshatter View Post
    Hi, many thanks for sharing the RAW files! I can see that for your shutter speed the A7R-II does have some advantage in terms of shadow recovery. By stitching the A7R-II surely yields more details than the IQ180. Why do you get a black circle in the IQ180 file? The 17mm TS-E should be able to cover the whole sensor.

    However, for long exposure shots, the A7R-II may not be a good choice.

    For long exposure shots:

    A7R-II performs even worse than Canon 5DSR
    A7R-II heats up quickly during long exposure
    A7R-II darkframe comparison (RAW files) against 5DSR and other Sony sensors
    A Chinese review of A7R-II doing poorly in long exposure

    Base ISO or high ISO, the A7R-II is not suitable for long exposure. You might even get better image quality with your IQ180 in the 10s-120s territory.

    Based on the comparison between A7 and A7-II, i.e. no degradation due to 5-axis IS, it is probably true that BSI sensors are not suitable for long exposure. If it's true then it's such a shame that the Rodenstock and Schneider wide lenses cannot be resurrected by a perfect CMOS digital back based on BSI...

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    Re: IQ180 vs Up-Res A7R2

    I agree with vjbelle regarding my original point of this being a print IQ test.

    The point on FOV is correct, however because you need to crop out the outer 1/4 to 1/3 of the entire image, you loose pretty much all of the resolution advantage of the IQ180 for printing purposes. In this regard the advantage of the IQ180 is pretty much nill.

    Quote Originally Posted by vjbelle View Post
    With the lens centered there is a lot, to me, of vignetting. Once that vignetting is cropped out the image is almost identical to the Sony image - other than format dimensions. If the vignetting is included to calculate FOV then, of course, the FOV is increased. BUT the vignetting has to be cropped out to get a usable image - at least for me. The first image is the lens centered on the FPS/IQ180. The second image is the cropped version. The third image is the Sony A7Rll with the same lens. What am I missing? If the lens is shifted on the IQ180 to eliminate vignetting the image becomes larger and field of view increases. BUT..... I can duplicate that with the Sony. Tell me what is gained?

    Victor

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    Re: IQ180 vs Up-Res A7R2

    Quote Originally Posted by vjbelle View Post
    With the lens centered there is a lot, to me, of vignetting. Once that vignetting is cropped out the image is almost identical to the Sony image - other than format dimensions. If the vignetting is included to calculate FOV then, of course, the FOV is increased. BUT the vignetting has to be cropped out to get a usable image - at least for me. The first image is the lens centered on the FPS/IQ180. The second image is the cropped version. The third image is the Sony A7Rll with the same lens. What am I missing? If the lens is shifted on the IQ180 to eliminate vignetting the image becomes larger and field of view increases. BUT..... I can duplicate that with the Sony. Tell me what is gained?

    Victor
    Frankly, I don't think you understand what you are looking at or discussing at all. How can you possibly not see that the images you quote in your post are shifted substantially?

    I'm not sure how much more simply it can be said than "unshifted the Canon 17 TSE covers the IQ180 sensor".

    And I'm getting extremely bored with having to say it.
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    Re: IQ180 vs Up-Res A7R2

    Quote Originally Posted by gerald.d View Post
    Frankly, I don't think you understand what you are looking at or discussing at all. How can you possibly not see that the images you quote in your post are shifted substantially?

    I'm not sure how much more simply it can be said than "unshifted the Canon 17 TSE covers the IQ180 sensor".

    And I'm getting extremely bored with having to say it.
    ??????? What???? Please explain the first image in my post - the one with all of the vignetting. That image is a centered 17mm TSE on an FPS with an IQ180 back. Sure doesn't look to me like the sensor is covered. I'm not saying that the image circle isn't large enough to cover the IQ180 sensor but that the captured image isn't. To take advantage of the large image circle the lens must be shifted and the resulting files stitched. The same thing can be accomplished with the Sony.

    Victor

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    Re: IQ180 vs Up-Res A7R2

    Quote Originally Posted by f8orbust View Post
    Never said it did.

    I said performance is dependent on the lens being used. Just because all the latest R/S (RF) design lenses are good (however you define 'good') does not mean that all good lenses are R/S (RF) designs.

    It's been common knowledge pretty much from day one that the sensor in the IQ180 behaves badly when shifted with good lenses from Schneider (and no, a lens doesn't suddenly become 'bad' because it won't play ball with a particular sensor). Which is a shame, because the S/K WA designs (in particular) have large ICs that you might want to perform large shifts with.

    This is why the emerging BSI technology is important, since it promises to behave well with all lenses.

    Jim
    My sincere apologies - the crucial bit in your post "where the angle of light hitting the sensor at the edge of the IC is acute ?" somehow didn't register.

    I stand corrected on that point.

    Kind regards,


    Gerald.

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    Re: IQ180 vs Up-Res A7R2

    Quote Originally Posted by vjbelle View Post
    ??????? What???? Please explain the first image in my post - the one with all of the vignetting. That image is a centered 17mm TSE on an FPS with an IQ180 back. Sure doesn't look to me like the sensor is covered. I'm not saying that the image circle isn't large enough to cover the IQ180 sensor but that the captured image isn't. To take advantage of the large image circle the lens must be shifted and the resulting files stitched. The same thing can be accomplished with the Sony.

    Victor
    You picked them in an attempt to support your argument. You explain them.

    Here's one to support mine.



    17TSE. FPS. IQ180.

    One frame.

    Unshifted.

    Uncropped.

    No keystone correction.
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    Re: IQ180 vs Up-Res A7R2

    The images I posted were from the files made available in post #37. You can download them for yourself and see for yourself.

    Victor

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    Re: IQ180 vs Up-Res A7R2

    Alpa made available a document that outlined the image size that would result from using various lenses including 35mm lenses. For the life of me I can't find it in my documents or on the Alpa site anymore but when 35mm lenses were used, via various adapters, the resulting pixel dimensions for phase one backs were compiled in a table. They were reduced as compared to a medium format lens because the lens simply wasn't able to fill the sensor completely. If I can find that anywhere I'll make it available.

    Victor

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    Re: IQ180 vs Up-Res A7R2

    I think victor means this doc? It certainly shows full sensor coverage with minimal vignette with the 17TSE in landscape mode unshifted.

    https://www.alpa.ch/_files/20131006_...PS_low-rez.pdf
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    Re: IQ180 vs Up-Res A7R2

    Graham..... that is not the doc. I have seen that doc and it, for sure, shows that the 17mm TSE covers the sensor with minimal vignetting. The doc I'm looking for is not on their site anymore. I think that something is surely amiss. The poster that provided the downloads (post #37) surely labeled everything and the downloads are accurate raw files - in that they are Phase files and Sony files. I have relied on those files for my posts - and have also relied on my recollection of the doc that was provided by Alpa. If I had all of this stuff then this would all be moot as I would know for myself. I have no reason to doubt Gerald but, again, something is surely amiss. Why would the poster provide a file that is not accurate? Why is it different than Gerald's in the fact that it is very vignetted? What is going on?

    Victor

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    Re: IQ180 vs Up-Res A7R2

    I can't say. I have the 17, 24 & 45TSE lenses and FPS but cropped IQ150. The vignettes image from Chris almost looks the vignette I'd see with my 45mm. With the 17TSE I don't get vignetting like that at all even with rise/fall.

    I don't know ... The raw is pretty self evident but I haven't seen that with my 17tse and nor would alpa or Gerald's image suggest that it should be so bad.

    hmm, just wondering if Chris shot the 17TSE with the lens shade on the FPS?
    Last edited by GrahamWelland; 23rd August 2015 at 20:21.
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    Re: IQ180 vs Up-Res A7R2

    To the OP:
    nothing new here, I mean 40/45mpx mfdb has been around for long now...so if you only need 40mpx then you could have bought an iq140 or a p45 instead of the iq180 ...
    If you need 80mpx then 40 will never do the job...as if you need 40 then 20 will never do it too!

    To vjbelle: it is clearly a shifted image probably by 8mm ...
    (kind advice: search for horizon�� )

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    Re: IQ180 vs Up-Res A7R2

    Quote Originally Posted by gerald.d View Post
    17TSE. FPS. IQ180.

    One frame.

    Unshifted.

    Uncropped.

    No keystone correction.
    Gerald, I have come to the conclusion that you are completely right. The image circle from the 17mm TSE covers the IQ180 Sensor..... just covers it. The raw file that I downloaded from post #37 has to be erroneous. I wish that poster could provide some more insight.

    Victor

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    Re: IQ180 vs Up-Res A7R2

    Quote Originally Posted by vjbelle View Post
    The raw file that I downloaded from post #37 has to be erroneous. I wish that poster could provide some more insight.

    Victor


    Victor, as i said in the previous post take a look at the image posted by chrismuc, i mean take your time to search for horizonline, then you'll understand that this shot is shiffted !!

    (i think: Top image vigneting is from image circle, bottom vigneing is from barrel/mechanismvigneting, because of the shift)

    This shot is probably shiffted by 8mm ...

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    Re: IQ180 vs Up-Res A7R2

    What you have observed does make sense. Maybe that is why Gerald came to the conclusion that the image was shifted...... As I thought about it I failed to take into account the barrel/mechanism vignetting and was looking for vignetting only on one side..... not uniform vignetting. Maybe Gerald could chime in or could show what happens when the lens is shifted 6-8mm. Its obvious that when on the front of an IQ180 there is no room for shifting without vignetting.

    Victor

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    Re: IQ180 vs Up-Res A7R2

    This is more of what I expected to see if the 17mm TSE were shifted. The lens with the smallest image circle that I own is my 35XL. I shifted 18mm on my STC to show the vignetting.... it is only on one side...... I didn't expect to see an equalized vignette as was shown by the file in post #37.

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    Re: IQ180 vs Up-Res A7R2

    Victor
    You are talking about my IQ180 file. I said from the very beginning that it is with TSE17 shifted 12mm upwards.

    Actually with some knowledge of perspective one can see it from the picture.

    Click image for larger version. 

Name:	IQ180+TSE17-12mm-shift.jpg 
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    In an unshifted picture, with horizontal camera orientation (this means vertical lines in architecture are vertical, not tilted), always half of the picture must be below, half above a virtual horizontal line given by the elevation position of the camera above ground. I added this virtual line in red to the picture you are refering in your post, and as you see, that line is much below the center of the picture recorded by the sensor. The reason is that the lens was fully shifted upwards.


    The vignetting on the top side is due to the image circle of the TSE 17 (about 67mm) which is insufficient for the shifted image.

    The vignetting on the bottom side does NOT come from the image circle restriction but because the back barrel of the lens respectively the diameter of the Canon EF mount is too small (the EF mount never was meant to be used with medium format sensors plus shift).

    This fact was discussed previously in another thread and every other user (like gerald) can confirm it.

    Christoph

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    Re: IQ180 vs Up-Res A7R2

    Thank you for the explanation.....

    Victor

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    Re: IQ180 vs Up-Res A7R2

    I'd love to make more contributions with demonstrations and further dig into how C1 does its colors, but I don't really have time with that. The only reason I've dug into it this far is so that my profiling project can produce profiles for it. It's time consuming to do this kind of stuff, and now I'd rather put that into improving my own color profiling engine.

    Anyway here's a short one on the color correctness of Capture One. I don't have an IQ180 shot of a subject of to me known color, such as a color checker, so I can't compare for IQ180 specifically. But for demonstration, here's an example from a P45+:

    First Capture One's default profile result:

    Name:  p45-c1.jpg
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    Then a calibrated result:

    Name:  p45-calib.jpg
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    Both with "standard film curve" applied, the calibrated profile is generated by an in-development DCamProf using it's "neutral tone reproduction operator" whose purpose is to maintain color appearance over changed contrast (increased in this case). Feel free to compare to your own color checker.

    My own observations of C1: dark blue is much too bright, the left orange is more yellow than the actual orange, overall saturation is a little bit too low (with exception in the foliage range for example). Those are the larger errors, there are smaller too.

    The DCamProf result may be a tad bit high on saturation, but overall the color appearance match is a ton better although not 100% perfect. Doing a side by side check with a calibrated monitor and a real color checker under sane light should make this obvious to anyone.

    Now there are reasons why C1 has made the colors like that. That dark blues are too bright is probably because they have reduced or even skipped lightness corrections, as that can in some circumstances negatively affect gradients, and lightness errors while easy to detect in a side-by-side comparison they're least objectionable and hard to detect if you can't do a direct comparison with the original.

    While lightness errors is probably largely due a side effect of hardware limitations, the hue errors are most likely designed. I've noted that skin tones are often made less yellow than reality for example probably because many think that's more flattering. More saturation in the foliage range may be a landscape adjustment. Why they have brought orange and yellow-green so tightly together I don't really know. It could be a side effect - sometimes you increase color separation in some color range, but that means that you must decrease it in some other.

    Note that I do not believe that the most accurate color means the "best" color, but I do believe that maybe it's not to the photographer's best interest that the manufacturer designs looks for them. Maybe the photographer should herself/himself be more in control.

    During my work with camera profiling I have noted how easy it is to "fool" oneself and think, "wow - this looks really accurate", for example if you shoot a subject in one room and look at a screen in the next. When you bring up the possibility with side-by-side comparisons you note that the bundled profiles are not very accurate at all. This does say though that color don't really need to be accurate for most applications. It has made me very skeptical about various claims of "accurate" color out of the box though. We see things we want to see, and the eye/brain is very forgiving and good at filling in.

    The P45+ is an old sensor which has less overlap of color filters than a more recent like the IQ180. This means that it's easier to make saturated colors with less noise (good as the sensor is a bit noisy too), but harder to separate colors. With increased signal-to-noise ratio color filters can now be more overlapping allowing finer color separation capabilities, at the cost of noise increase when making saturated colors (which isn't as harmful as before due to the better S/N ratio). Most differences you see are designed in the profile though.

    I'd love to see a similar comparison made with an IQ180, I think you would get a similar result, that is a perfectly alright realistic look but with a few quite obvious color errors that for various reasons have been designed into the profile. So forgive me, before I see such a demonstration I cannot really trust anyone's word that the bundled profiles provide accurate color.
    Last edited by torger; 24th August 2015 at 10:06.

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    Re: IQ180 vs Up-Res A7R2

    Film curves will not result in accurate color. Not a great default to wok with.

    Posting a color image on the web is not a great way to have a discussion about color accuracy. Besides, how are you shooting this target? What are your viewing conditions? How are you measuring color?

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    Re: IQ180 vs Up-Res A7R2

    Quote Originally Posted by Shashin View Post
    Film curves will not result in accurate color. Not a great default to wok with.

    Posting a color image on the web is not a great way to have a discussion about color accuracy. Besides, how are you shooting this target? What are your viewing conditions? How are you measuring color?
    I assume the interested persons have calibrated screens and color managed web browsers that can display sRGB images in the intended color space. I do. The color errors are large enough to detect with uncalibrated screens too, if you have a wide gamut unmanaged screen the colors will be over-saturated, but that for example the orange and yellow-green are really close together should be quite easy to see anyway.

    I chose film curve (or more specifically a contrast S-curve) because very few use linear rendering for general purpose photography, which in C1's case is not linear in any case as the profile LUT itself applies a small curve. If we were discussing reproduction work we would discuss C1's "Cultural Heritage Edition", whose accuracy should be good according to what I have heard (they have other profiles).

    Photographer's interest in accurate colors doesn't end because of the curve though. I generally try to use the term "color appearance", as accuracy makes people confused and they start think reproduction work, so sorry for using the forbidden word. Color appearance modeling is about taking that colorimetric color and transform it for a specific scene, reproduction device and viewing condition and make it appear the same as the original. The tone curve is actually a primitive color appearance model. Due to the Stevens and Hunt and other psychovisual effects a linear rendering of say a sunny outdoor scene will appear flat when displayed with a linear curve, but with an S-curve the original appearance in terms of contrast can be restored. The challenge of color appearance remain though.

    Color science haven't done that much modern research on tone curves, but instead went straight to more complex scene/image appearance models which we as photographers would call tone mapping, Fairchild and Johnsons iCAM was an early attempt. If you want to retain color appearance on a contrast curve there's thus not much established research to rely on so you have to come up with your own model, and yes it will be filled with compromises as you can't take local contrast or other spatial properties into account. It can however be made to work decently well in a broad range of cases, I've developed one for DCamProf with the help of my own and other's expert eyes, and I'm sure Phase One have their own in-house model. A basic starting point is the the more contrast you apply, the more you must increase the saturation, but the model is more complex than that.

    Anyway, all color science is based on psychovisual experiments, mainly color matching experiments. Watch one color, compare to another, say if it matches or not. So just do it yourself in this case. Hold a color checker in one hand under a print viewing lamp, or window daylight, and compare to what you see on screen, like you would do with a print.

    The accuracy of color will be subjective, yes of course, like the whole area of color science is. I strongly doubt though that anyone would disagree that C1's dark blue is too bright, or that the yellow-green and orange are too close. The other errors are smaller and may need a more careful setup to thoroughly evaluate. As we have a contrast curve you should let the eye adapt to the overall contrast too and watch the image as a whole, that is not mask away so you see a single color patch (which then will appear too saturated).

    The purpose of the demonstration is to show that C1 doesn't render color with the original color appearance, as it's not its intention. If you think the example can't prove that even for the P45+ I can't really provide any further arguments to convince you on that point, and that's fair enough. I at least tried.

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    Re: IQ180 vs Up-Res A7R2

    This sort of stuff only interests pixel peepers. For practical purposes, including demanding fine art applications, the difference below very large wall sized prints is irrelevant.

    Moreover, the practical reality is useabilty in the field. I'm no longer prepared to lugg The back breaking weight of MF cameras around the place.

    A few years ago we marvelled at 39mp P45 CCD backs. If we can achieve similar performance from a Sony A7RII but with far less weight, and far better high ISO, then so far as I am concerned, its time to kiss MF goodbye.
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    Re: IQ180 vs Up-Res A7R2

    Quote Originally Posted by torger View Post
    The purpose of the demonstration is to show that C1 doesn't render color with the original color appearance, as it's not its intention. If you think the example can't prove that even for the P45+ I can't really provide any further arguments to convince you on that point, and that's fair enough. I at least tried.
    Well, it is a film rendering--I have no doubt you are not getting accurate color and to blame C1 for bad color with a film profile is a bit like blaming instagram filters for not getting accurate color as well. But you are not even showing you could even reproduce accurate color, so I am not sure the point except to say you should profile your camera and shooting conditions. And stop using a film profile.

    I am not sure why you are saying color scientists area not working on tone curves? Unless you control contrast you will never get accurate color. Which is why the film profile works against you. There are decades of work in tone curves and color, which is why there was no real contrast control for color film images. Sure, you had control with contrast masking or with dye transfer printing, but it was limited. But basically if you change the tone curve, you change the color and the relationships between colors. You cannot maintain accurate color and change contrast--linear response is great for color.

    Color is the human response to light. So it has to be visual. But that does not mean you cannot measure it. And even with visual inspection, the viewing conditions are very specific--not just the color of the light (include a high CRI), but its intensity as well. And window daylight is a horrible condition to view under if you are looking for color as it is too variable. You need to be very specific with viewing conditions and shooting conditions to do this work. Leaving solely to the visual system to provide the answers will not work very well.

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    Re: IQ180 vs Up-Res A7R2

    Quote Originally Posted by Shashin View Post
    Well, it is a film rendering--I have no doubt you are not getting accurate color and to blame C1 for bad color with a film profile is a bit like blaming instagram filters for not getting accurate color as well. But you are not even showing you could even reproduce accurate color, so I am not sure the point except to say you should profile your camera and shooting conditions. And stop using a film profile.

    I am not sure why you are saying color scientists area not working on tone curves? Unless you control contrast you will never get accurate color. Which is why the film profile works against you. There are decades of work in tone curves and color, which is why there was no real contrast control for color film images. Sure, you had control with contrast masking or with dye transfer printing, but it was limited. But basically if you change the tone curve, you change the color and the relationships between colors. You cannot maintain accurate color and change contrast--linear response is great for color.

    Color is the human response to light. So it has to be visual. But that does not mean you cannot measure it. And even with visual inspection, the viewing conditions are very specific--not just the color of the light (include a high CRI), but its intensity as well. And window daylight is a horrible condition to view under if you are looking for color as it is too variable. You need to be very specific with viewing conditions and shooting conditions to do this work. Leaving solely to the visual system to provide the answers will not work very well.
    One need to be able to differ between small errors and large errors. If we can't do that, we can't really have this type of discussion as we'll talk past each-other. An orange that becomes yellow is a large error. A slight change in saturation is a small error. If you think a tone curve must undoubtedly lead to color errors à la instagram effect filters then I think it will be difficult to discuss color in any meaningful way. I surely know about the limits of color constancy and chromatic adaptation of human vision, I know it well enough to have a feel for what is a large error and what is a small, and what will require a stable well-defined viewing condition, and what can do with less.

    The reason I'm saying color scientists don't work with tone curves, or tone reproduction operators as the scientific term is, is because most work is dated back prior to digital photography. It's not all true though, looking at this paper from 2002, "K. Devlin, A review of tone reproduction techniques" you get a nice overview of some of the techniques, both spatial and non-spatial. It's 13 years old though, and after that what I find is "tone mapping", ie spatially varying tone reproduction operators. The algorithms we see in raw converters are in-house proprietary, not standardized public algorithms. CIE has no recommended tone reproduction operator. I think most work regarding tone curves is actually done in video, not stills. There are many raw converters today and most have different methods to apply tone curves, as there is no standard method to just pick. Adobe uses their RGB-HSV hue-stabilized tone curve. Then on top of the tone curve raw converters usually apply subjective adjustments. Which I see that C1 have done and I tried to demonstrate, but apparently it's not working that well.

    Concerning measuring color. What we measure when we use spectrometers and get tristimulus values is the spectrum which is integrated with the "standard observer", which is based on psychovisual color matching experiments made in the 1930s, if I remember correctly on 15 trained individuals or so. The standard observer has been reviewed several times since then, but the 1931 standard observer still stay the standard as CIE has as a principle to not change standard if there is only a small improvement. That is what we measure is how well something matches a psychovisual experiment. Chromatic adaptation transforms are the same, mathematical models that have been generated to fit psychovisual experimental data. We always end up in human eyes and judgments, so far there's been no measurement probes put into the eye or brain to measure an actual signal.

    Today we know that the pure split between colorimetric tristimulus value ("eye signal") and "brain processing" is not really correct, stuff happens in the eye too that changes what signals that are sent to the brain. However the field of color science is a pragmatic one and this split has been maintained and instead models have been adapted to compensate. This is quite clear concerning dark adaptation.

    To evaluate the result of a tone reproduction operator we can't rely on any experimental data or any standardized model derived from that, because it haven't been made. We do have models for various effects, which most ended up in the CIECAM02 model (extensively used in DCamProf by the way), but it still does not have adequate tools to evaluate tone reproduction operators. For that the most effective way is visual A/B comparison with the linear colorimetric rendering and let the eye adapt for contrast and do that with a number of trained individuals. This is what I do.

    For the particular comparison a few posts backs I think the errors are large enough to not require any rigid test setup. Anyone interested in a more thoroughly made test can do it themselves though, and they will arrive to the same conclusion -- C1has adjusted color subjectively to provide a look, their intention is not to keep color appearance as true to the original as possible.

    The original question was if IQ180 provided more accurate color in C1 than A7rII because of a better sensor hardware which some seem to believe. By showing that C1 doesn't really have the intention to provide accurate colors (and also show how much different profiles can change color) I'm trying to show that we can't assume that color differences in C1 are due to hardware differences, because I don't think the IQ180 sensor really is any superior than the A7rII concerning color, but I do think that the color profiles for the IQ180 can be more well-designed, actually I'm surprised if they aren't. It would be a mistake by Phase One to make a better profile for a competitor.

    When you pay those tens of thousands of dollars of hardware you may think you're buying into the hardware, but a very big part of the value sits in the raw conversion and profiles. Another pricing model which I think would better mirror the value would be to cut the IQ180 price to 1/4th and then put the remaining money into a special very expensive C1 software license . If pricing were like that I think photographers would start to think about trying to get more control of color rendition and actually make their own profiles, which few do today. It's a hen and egg problem though as there aren't really any good tools available. (My own project is a command-line only tool so it won't be broadly used, although it might become commercial with a GUI sometime in the future)
    Last edited by torger; 25th August 2015 at 00:44.

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    Re: IQ180 vs Up-Res A7R2

    The idea to profile for each condition is interesting, but it's just not going to happen until cameras can do it automatically on the spot. We're "stuck" with general-purpose profiles for still some time.

    Linear response is great for reproduction photography, but that is about it. It's really bad at making a perceptually realistic rendering of a real scene, it allocates way too much of the scarce reproduction media dynamic range to the highlight range and make the overall scene look unrealistically flat and dull. While individual hues surely will appear accurate assuming a colorimetric profile, contrast will not.

    So we apply contrast. Contrast will indeed change color appearance, even if we apply it in the luminance channel only. This can be compensated for though, but there are no standardized models to do so. It's not that easy to implement either. In the proprietary world there's a mix between doing this compensation (in proprietary ways that vary from manufacturer to manufacturer) and making subjective adjustments to create a look.

    If you do it right a profile that applies contrast and compensates the appearance effects will make a more realistic rendering of real scenes than a linear purely colorimetric profile.

    The secret to "good" camera color lies in how to deal with the relationship between contrast and color appearance. Most camera profiling software can't do it, and most photographers can't either, which leaves the power of color with the manufacturer. This is a very strong "weapon" indeed, as it can be the decisive factor for choosing say an IQ180 over an A7rII.

    With spatially varying appearance models, as much of the more recent color science research has been focused on, the concept of a global contrast curve has been dropped. The idea there is that you start with a linear colorimetric registration of the scene, including absolute light levels, and then the eye-brain's response is simulated in an appearance model and translated to the output media. Those models are not entirely stable though, and I don't see that contrast curves concept will be dropped in the still photography world anytime soon. No raw converter on the market today is based on this concept, although you can to some extent do it in RawTherapee via it's CIECAM02 mode.

    Commercially it's in any case better to employ the old-school model with contrast curves and subjective looks, as it makes it easier to differentiate cameras, and even lock people in. I've got requests from folks that want to recreate the Leaf look in Phase One digital backs, as they due to business decisions switched to P1 hardware, but are so used to work with Leaf's distinct look that they have a hard time making the same result with Phase One, despite the exact same sensor hardware. I'm not surprised, it is hard.

    Although it would be quite possible to make "look translators", and icc to DNG profile conversions etc it's however not anything I will spend my valuable time on. I'm much more interested in creating something new than reverse engineering others. I've had to suffer through plenty of reverse engineering already.

    I don't like lock-in and imposed looks so I have used own custom profiles for many years. However I have never been fully pleased with what the profilers can do, which lead up to making my own software for that.

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    Re: IQ180 vs Up-Res A7R2

    Quote Originally Posted by torger View Post
    Concerning measuring color. What we measure when we use spectrometers and get tristimulus values is the spectrum which is integrated with the "standard observer"
    There are full spectrum color meters like the Sekonic C-700. Would that be useful?

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    Re: IQ180 vs Up-Res A7R2

    Quote Originally Posted by jerome_m View Post
    There are full spectrum color meters like the Sekonic C-700. Would that be useful?
    I guess you mean that when you shoot you record the ambient light spectrum (scene illuminant) using this type of device, and then in the raw conversion step you could somehow provide the light spectrum and the profiles would adapt.

    When you profile a camera having the reflectance spectra of all the test patches and the illuminant spectrum is somewhat useful as you then can calculate the exact tristimulus values of the standard observer and calibrate against that. If your light is decently in the area of D50-D65 the profiling result will be almost the same anyway, so I'd say it's not that critical. I do record the spectrum myself though when I profile a camera.

    If we designed a new raw conversion pipeline that knows the color filter response of the camera (known as Spectral Sensitivity Functions, SSFs, in the scientific literature) we could generate new profiles "on the fly" by using the spectrum of the illuminant. If it really would provide relevant value though I don't really know. I doubt that it would, without adding a lot of further appearance modeling on top, as when color appearance becomes really complicated to match we are at lights that make other things happen like dark adaptation, partial chromatic adaptation etc. It would be a very interesting research project.

    It's worth noting though that all established raw conversion software is sort of stuck in "film mode", there's a lot of new ways to model and render color, but noone is trying it. And it's not a surprise as it would be extremely disruptive to the existing color conversion pipelines. Don't fix if it ain't broken. Noone is asking for it, and I'm actually not sure how much value it would provide. I'd love to experiment with it myself though... but there's only so much time!

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    Re: IQ180 vs Up-Res A7R2

    I will also agree that comparing an upsized image file to one that has not been increased in pixel amount is not a fair comparison. This comes from one who, for years, has been looking for something smaller and lighter that will satisfy me regarding quality as much as my experience with Phase One backs has in the past...from the P25 on to my current P65+. Now I really don't need more than 40 - 50 megapixels these days, so one of the reasons I have the A7RII. I just did a comparison of a wall of fishing equipment and ski stuff hanging on the wall in my garage using both my Otus 55 1.4 and my Sony/Zeiss 55 1.8...same lighting, same iso at 50, same C1 setting, etc. I admit I'm not a pro at making controlled comparisons but once one sees the Otus 1.4 against the Sony 55 1.8 it become obvious that to really compare medium format digital one has to have an incredibly good 35mm lens as in the Otus 55. My Phase One is not here in Colorado with me so can't make comparison with that now. This is only to make the point if one is going to compare med. format digital to 35mm A7RII lens quality does come into play as does pixel count. Eleanor

    Quote Originally Posted by ErikKaffehr View Post
    Hi,

    My take is really that once we upsize an image we are loosing image quality.
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    Re: IQ180 vs Up-Res A7R2

    Quote Originally Posted by jerome_m View Post
    There are full spectrum color meters like the Sekonic C-700. Would that be useful?
    For color science, they are not precise enough. Nor is trying to determine illuminant spectra from color cameras. And hence the problem with color--it is extremely difficult to work with.

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    Re: IQ180 vs Up-Res A7R2

    Quote Originally Posted by torger View Post
    I guess you mean that when you shoot you record the ambient light spectrum (scene illuminant) using this type of device, and then in the raw conversion step you could somehow provide the light spectrum and the profiles would adapt.
    I don't mean anything, I don't know how to use such a device. I just wonder if the device is useful and I ask.

    Quote Originally Posted by torger View Post
    It's worth noting though that all established raw conversion software is sort of stuck in "film mode", there's a lot of new ways to model and render color, but noone is trying it. And it's not a surprise as it would be extremely disruptive to the existing color conversion pipelines.
    There is actually lots of work done presently in the movie industry. They have the following problem: they want to use LED lights, which need far less electricity. The LEDs look like daylight to the human eye, but not quite so to the cameras. This is very much a problem for make-up: the make-up artist chooses colours and they don't fit when the cameras run...

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    Re: IQ180 vs Up-Res A7R2

    Quote Originally Posted by jerome_m View Post
    I don't mean anything, I don't know how to use such a device. I just wonder if the device is useful and I ask.

    There is actually lots of work done presently in the movie industry. They have the following problem: they want to use LED lights, which need far less electricity. The LEDs look like daylight to the human eye, but not quite so to the cameras. This is very much a problem for make-up: the make-up artist chooses colours and they don't fit when the cameras run...
    There's a lot of development going on in the movie industry software-wise, if one wants to learn something new it seems to be a good place to be in. The problem with the LEDs are that they're not full spectrum, and thus the differences between cameras and eyes are exaggerated. I have experimented too little with profiling with peaky spectra to know what the possibilities and challenges are. In theory making a specific profile for the LED would make it work, but I'm not sure if those profiles are "stable", that is how well they will work for broad color ranges.

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    Re: IQ180 vs Up-Res A7R2

    Ok back to the original topic "too many pixel" vs. "way too many pixel" ;-)

    I did comparison shots between the Sony A7RII (+ Metabones IV) and the Contax 645 + IQ180 at three +- equivalent focal lengths.

    I uploaded full res jpgs, I tried to match the colors roughly (using standard profiles) in ACR, sharpening about 60%/0.5 pixel, CA corrected, shadows lifted up to 50%.

    1. A7RII + Zeiss CY 21f2.8 @*f8 vs. Contax 645/IQ180 + Contax 35f3.5 @*f11

    Name:  CF003962-Contax645+IQ180+35f2.8@f11-1200.jpg
Views: 724
Size:  352.0 KB

    Sony A7RII
    https://dl.dropboxusercontent.com/u/...1f2.8%40f8.jpg

    IQ180
    https://dl.dropboxusercontent.com/u/...f2.8%40f11.jpg


    2. A7RII + Sigma 50f1.4 Art @*f8 vs. Contax 645/IQ180 + Contax 80f2 @ f11

    Name:  CF003963-Contax645+IQ180+80f2@f11-1200.jpg
Views: 691
Size:  274.4 KB

    Sony A7RII
    https://dl.dropboxusercontent.com/u/....4Art%40f8.jpg

    IQ180
    https://dl.dropboxusercontent.com/u/...80f2%40f11.jpg

    3. A7RII + Zeiss ZE 135f2 Apo @*f5.6 vs. Contax 645/IQ180 + Mamiya 200f2.8 Apo @ f8

    Name:  CF003976Contax645+IQ180+Mamiya200f2.8@f8-1200.jpg
Views: 676
Size:  264.1 KB

    Sony A7RII
    https://dl.dropboxusercontent.com/u/...5f2%40f5.6.jpg

    IQ180
    https://dl.dropboxusercontent.com/u/...0f2.8%40f8.jpg

    Btw., the most impressive result for me is the nothing but stunning IQ of the Zeiss 135 Apo.

    Enjoy, Christoph
    Thanks 2 Member(s) thanked for this post

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    Re: IQ180 vs Up-Res A7R2

    Thanks for the comparison. I only download the last samplee, but it looks that the IQ has better DR than A7RII unlike the previous statement here.

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