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Thread: wide lens IQ 180 shoot out: Digitar 28XL versus Digaron 32HR-W

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    wide lens IQ 180 shoot out: Digitar 28XL versus Digaron 32HR-W

    dear all,
    beware of the new Schneider 28mmXL Digitar on the IQ180.
    It got uncontrollable color cast EVEN WITHOUT SHIFT!

    A fellow getDPI forum member Chris Hauser and myself met in Hong Kong last weekend and had a fun shoot out comparing the Schneider 28XL and 43XL with the Rodenstock 32HR-W and 40HR-W. He was on an Arca with the Rodies and myself on an Alpa with the Schneider both equipped with IQ180s.

    to simplify our findings I simply grouped those images and made screen shots. The lens and shift amount can be found below the respective images.

    The lens test were as follows:
    - 32HR shifted up: 0, 5, 10 , 15 mm plus corresponding LCCs
    - 28XL shifted up: 0, 5, 10 , 15 mm plus corresponding LCCs
    - 32HR shifted left: 5, 10 , 15 mm plus corresponding LCCs
    - 28XL shifted left: 5, 10 , 15 mm plus corresponding LCCs

    Please note while both the Arca and the Alpa allowed for more than 15 mm upward shift the 28XL due to its proximity to the sensor pane can't be shifted higher than 15mm on the Alpa. The 32HR peaked at about 19mm when we reached the image circle of that lens.
    Also the camera were right next to each other and there we minimal light changes during the 15 minutes of shooting these test.
    I deliberately did NOT make any changes to the LCC or the image itself (no adjustments, straight out the camera).
    All were shot with the same IQ180 on f11 1/8sec (1/4 for LCC) and WB set to Daylight.
    Despite the lack of any scientific procedure I think the images speak a clear message:
    the 28 Digitar as great as it is on other backs is NOT recommended on the IQ. I had to buy the bullet and sold it right away.

    On another note: thanks to Jack and Guy for this forum plus everybody's else's accumulated wealth of information & not to mention the fact that you bring folks together as well.
    Especially in this part of the world (China) its hard to initiate a shoot out with such rare equipment specs.
    Special thanks also to Christopher for making me loose a few thousand bucks this weekend on the trade in :-)
    Hope some of you can avoid this costly mistake.

    Grischa

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    Re: wide lens IQ 180 shoot out: Digitar 28XL versus Digaron 32HR-W

    "the 28 Digitar as great as it is on other backs is NOT recommended on the IQ."

    at least on the IQ 180...

    Anyone test it on the two others IQ ?

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    Re: wide lens IQ 180 shoot out: Digitar 28XL versus Digaron 32HR-W

    Rupho, where do you buy (and sell) your Alpa gear?

    Paul

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    Re: wide lens IQ 180 shoot out: Digitar 28XL versus Digaron 32HR-W

    I guess I'm not sure I understand what you are showing for the LCC's. These look unprocessed. Are you saying when you use C1 and process the LCC using the wide angle analysis even at zero shift the 28mm doesn't clean up and can't be fully corrected?

    Would you please post the 28 no shift image after the LCC is applied.

    Thanks,
    Terry

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    Re: wide lens IQ 180 shoot out: Digitar 28XL versus Digaron 32HR-W

    I'm not seeing the 43XL v's the 40HR-W images.

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    Re: wide lens IQ 180 shoot out: Digitar 28XL versus Digaron 32HR-W

    Quote Originally Posted by wentbackward View Post
    Rupho, where do you buy (and sell) your Alpa gear?

    Paul
    Paul, being in Hong Kong I buy my Alpa gear though Beijing. Fabulous and extremely knowledgeable team there. so far I have not sold a thing except for the Schneider 28mm lens after 3 month of use.



    Quote Originally Posted by TEBnewyork View Post
    I guess I'm not sure I understand what you are showing for the LCC's. These look unprocessed. Are you saying when you use C1 and process the LCC using the wide angle analysis even at zero shift the 28mm doesn't clean up and can't be fully corrected?

    Would you please post the 28 no shift image after the LCC is applied.

    Thanks,
    Terry
    Terry, what I am showing in regards to the LCCs is the fact that the 28XL displays extreme color casts even unshifted . I think uncorrected LCCs tell the story of what where the limits are. I attached the 28XL unshifted and corrected. I think unshifted this lens works but even then the LCC makes the edges "lifeless" there is not much color left. Also I pushed the Light Falloff to 50% otherwise the image would have been rather bright.
    I also attached a 100% screen shot that shows the side of that very same image displaying bending even unshifted.
    The point I am trying to make is: this lens is only correctable unshifted and the stated image circle of 105mm is unrealistic on an IQ180.
    I guess everybody can draw their own conclusions of whether this lens works for them. In terms of size , sharpness and built quality its absolutely great , but for some reason its causing color cast havoc to an extend where its not worth to bother with IMHO.
    Grischa

    Gazwas,
    we also shot on the 43XL and 40 Hr. the differences were not nearly as severe compared to the 28XL / 32HR.
    Though there was more color coast creeping in on the 43mm at around 15mm on the long side (again with an IQ180) so I did not bother posting it

    Grischa

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    Re: wide lens IQ 180 shoot out: Digitar 28XL versus Digaron 32HR-W

    Hi Grischa,

    Very informative test. I'm surprise to see so many member are actually from Hong Kong! I met Chris on Tuesday for a shoot as well.

    Yat

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    Re: wide lens IQ 180 shoot out: Digitar 28XL versus Digaron 32HR-W

    This color cast topic with the iQ180 and wide angle lenses - symmetrical design like Schneider but also asymmetrical designs like Rodenstock - seems to me a terrible design flaw of the iQ180 back.

    In comparison, the Canon sensors of the 5D2 and 1Ds3 with very wide angle lenses like the 24TSE and 17TSE at full horizontal shift show no color cast at the shifted edges.

    The optical construction in front of the Dalsa sensor of iQ180 seems too deep (maybe it was also not such a good idea not to use micro lenses like Canon does) and at steep angles not all frequencies of the light are transmitted in the same way to the sensor pixels. With such strong color cast, a pp software solution is not very appropriate because noise is added and the cast compensation shifts the range of each color channel into a more non-linear area.

    I'm wondering what Phase One/Dalsa is explaining regarding this serious topic and I would like to know what in detail they changed in sensor design from the iQ160/P65 to iQ180/AptusII 12 that make them work worse with wide angle lenses.

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    Re: wide lens IQ 180 shoot out: Digitar 28XL versus Digaron 32HR-W

    Quote Originally Posted by chrismuc View Post
    This color cast topic with the iQ180 and wide angle lenses - symmetrical design like Schneider but also asymmetrical designs like Rodenstock - seems to me a terrible design flaw of the iQ180 back.

    In comparison, the Canon sensors of the 5D2 and 1Ds3 with very wide angle lenses like the 24TSE and 17TSE at full horizontal shift show no color cast at the shifted edges.

    The optical construction in front of the Dalsa sensor of iQ180 seems too deep (maybe it was also not such a good idea not to use micro lenses like Canon does) and at steep angles not all frequencies of the light are transmitted in the same way to the sensor pixels. With such strong color cast, a pp software solution is not very appropriate because noise is added and the cast compensation shifts the range of each color channel into a more non-linear area.

    I'm wondering what Phase One/Dalsa is explaining regarding this serious topic and I would like to know what in detail they changed in sensor design from the iQ160/P65 to iQ180/AptusII 12 that make them work worse with wide angle lenses.
    The Canon 17TS and 24TS use strongly retrofocus designs which brings the lens away from the sensor and thus avoids most of these issues. They must, since neither Canon nor Nikon make a pro body without a mirror so the lens must be mounted in front of a mirror box. Even so a 7D with a 17TS will show color cast in the corners with large movements- don't take my word for it, just go shoot through a piece of white plexi and auto-level the resulting image. Notably AFAIK neither Canon nor Nikon have a software tool to deal with this (other than Capture One or other 3rd party software), and it will only become a larger issue when Canon and Nikon release next-gen bodies with full frame sensors with smaller pixels. Phase and Leaf have been aware of this fact of physics for a long time and have developed the LCC tool to address it as early as Capture One version 3.

    Also, generally speaking Microlenses exacerbate the issue of color cast, not rectify it. Of course that's only generally speaking as "microlenses" can be pretty varied in design, composition, and purpose. In other words the lack of microlenses on the IQ180 is a good thing - not a bad thing - when it comes to color cast.

    By the way you can in fact, can use a Canon 17TS or 24TS or any other such Canon or Nikon lens with a IQ180 (e.g. with the Hartblei Cam).

    For those interested Capture Integration's testing should be posted by the end of the day tomorrow and includes the 28XL, 35XL, 43XL, 60XL, and the 70HR. It agrees with this test - the 28XL was definitely the lens in that group that performed the least well (no surprise there given how extreme a design that lens is). Otherwise it's mostly good news.

    The opposite side of this argument of course is that the IQ180 gives the best dynamic range and color performance I've seen, while also giving the option for ISOs as low as 32 but also the best ISO3200 I've seen on any digital back. There is rarely a free lunch and a smaller usable image circle on the extreme wide angle XL lenses is one downside of the IQ180.

    Watch for that test tomorrow!

    Doug Peterson (e-mail Me)
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    Re: wide lens IQ 180 shoot out: Digitar 28XL versus Digaron 32HR-W

    Quote Originally Posted by gazwas View Post
    I'm not seeing the 43XL v's the 40HR-W images.
    Gareth
    here are some side shifts between the HR40 and the XL43mm in 5,10, 15mm intervals.
    Hope this helps
    Grischa

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    Re: wide lens IQ 180 shoot out: Digitar 28XL versus Digaron 32HR-W

    The Canon TSE 17mm with 12 mm shift on a 36 mm wide sensor relates to an image circle of 67 mm, the Rodenstock HR 32 mm with 13 mm shift on a 54 mm wide sensor relates to an image circle of 90 mm.

    In this case the angle of view of the 12 mm shiftet Canon TSE 17 is about 35% larger than the angle of view of the 13 mm shifted Rodenstock HR 32!

    Even if the Canon lens design is stronger retrofocus than the Rodenstock design, this much larger angle of view should relate to a steeper angle of light from the back of the lens to the sensor. Which is handled very well by the Canon sensor design but seems much less perfect by the Dalsa/Phase One/Leaf 80MP sensor design.
    (And one must consider that the Canon sensor even includes an AA-filter and a ultrasonic cleaning system which enhances the thickness of the sensor and therefore makes it more difficult to deal well with the steep angles of light.)

    I asked Stefan Steib from Hartblei how well the two TSE lenses perfom on the Hartblei cam with a 80MP back. I also aksed him how well (or worse) they perform regarding color cast compared to the P65 60MP back.

    And that's still my question for Dough: How much stronger is the color cast of the IQ180 compared to the iQ160 (especially with shifted Rodenstock 28, 32 and 40 mm lenses) and what is the difference in sensor design between the two sensor generations. The reduced pixel width of the 80MP sensor does not directly cause this problem, IMO it must be the ratio of pixel diameter to sensor depth or other geometrical design changes of the sensor.

    Looking forward your test results tomorrow!

    Christoph

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    Re: wide lens IQ 180 shoot out: Digitar 28XL versus Digaron 32HR-W

    Quote Originally Posted by chrismuc View Post
    The Canon TSE 17mm with 12 mm shift on a 36 mm wide sensor relates to an image circle of 67 mm, the Rodenstock HR 32 mm with 13 mm shift on a 54 mm wide sensor relates to an image circle of 90 mm.

    In this case the angle of view of the 12 mm shiftet Canon TSE 17 is about 35% larger than the angle of view of the 13 mm shifted Rodenstock HR 32!

    Even if the Canon lens design is stronger retrofocus than the Rodenstock design, this much larger angle of view should relate to a steeper angle of light from the back of the lens to the sensor. Which is handled very well by the Canon sensor design but seems much less perfect by the Dalsa/Phase One/Leaf 80MP sensor design.
    (And one must consider that the Canon sensor even includes an AA-filter and a ultrasonic cleaning system which enhances the thickness of the sensor and therefore makes it more difficult to deal well with the steep angles of light.)

    I asked Stefan Steib from Hartblei how well the two TSE lenses perfom on the Hartblei cam with a 80MP back. I also aksed him how well (or worse) they perform regarding color cast compared to the P65 60MP back.

    And that's still my question for Dough: How much stronger is the color cast of the IQ180 compared to the iQ160 (especially with shifted Rodenstock 28, 32 and 40 mm lenses) and what is the difference in sensor design between the two sensor generations. The reduced pixel width of the 80MP sensor does not directly cause this problem, IMO it must be the ratio of pixel diameter to sensor depth or other geometrical design changes of the sensor.

    Looking forward your test results tomorrow!

    Christoph
    Aren't you forgetting about how close these lenses are to the sensor. If you pull the lens away from the sensor isn't the angle of light hitting the sensor going to change. If you look at the IQ180 with the DF body and lenses and compare the 28mm lens for the DF vs the Schneider 28XL they will render very differently in terms of any color cast that needs to be corrected. This is similar to the issues that Leica had when developing the M8/M9 and having lenses that sit so close to the sensor.

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    Re: wide lens IQ 180 shoot out: Digitar 28XL versus Digaron 32HR-W

    The focal length of the lens can obviously has a relationship to the angle of view from the nodal point of the lens, but of course this is varied by the optical professors. The angle of light through the rear lens elements is only _equivalent_ and does not reflect the actual final exit angle from the rear of the lens, so two lenses of same focal length, one being actual the other being retro focus, will have vastly differnt final exit angles and therefore the same focal length can cause differing degrees of the colour cast problem. The wider the sensor the stronger the problem. Hence leica originally claiming that full frame digital was impossible. Although that seems like clever marketing now.

    The lenses on the sensor can be angle to compensate to a degree, but this is a compromise as what is right for one lens is wrong another.

    As light falloff is also a problem and under exposure over emphasis saturation, this also magnifies the problem.

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    Re: wide lens IQ 180 shoot out: Digitar 28XL versus Digaron 32HR-W

    HI Christoph/All

    well it is interesting that all the predictions I have done about Microlens cornershading and color casts have come true to the worst intent possible.
    This clearly shows that the concept of "true wideangles" as "digital lenses" (see Schneider whitepaper of some years ago) has failed. All the specialists saw this coming, Rodenstock has already reacted and made the 23mm retrofocus, so this was and is apparent.
    A "correction" of this kind of color cast in Software may result in a visible usable image file, but spoken from a point of lithography view, these files will give a hell of headaches to everybody trying to convert to CMYK -correct and print these in a qualitative way. Of course if you only work for the internet or RGB that may get through somehow, but if I remember right, most of us are still getting their life paid by the printing industry products.

    Ask any litho guy, he will tell you the truth about such files.

    I can only invite everybody to take a look at the images we have done on our HCam-B1 with the Leaf aptus II 12R with no visible color cast nor chromas at 200% and movements with the Canon TS17mm and TS24mmII - all the people who saw this on the recent PCP Tour here in Germany were speachless - ask Yair Shahar if you don´t believe me - I have given the sample pics to him as well as I have given them to Canon Germany.

    I have already contacted KN-Studiotechnik here in Munich and also Phase One to get a demo 180 IQ ASAP so we can proof this with the newest Phase One backs too.

    There needs to be a change in concept for digital wideangle Pro Photography on cameras using these lenses, the classic approach is coming to a limit as we can clearly see now. It is most interesting that the solution is already worked on- it happens in the consumer areas with small chips and 16Mpix - it´s called NEX, MFT and things that people like Ricoh and Foveon do.
    I´d also ask anybody to read Olympus four thirds whitepaper which was a milestone in my opinion about the future of digital photography.

    The Pro Range was somehow sleeping, but I think this is a wakeup call.

    Greetings from Munich
    Stefan Steib - HCam.de

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    Re: wide lens IQ 180 shoot out: Digitar 28XL versus Digaron 32HR-W

    Terry:
    I only referred to the Rodenstock lenses because they also are retrofocus designs similar to the Canon TSE lenses. The Schneider lenses with their symmetrical design (which leads to a much shorter distance between back lens and sensor and therefore steeper angles of light) are obviously less suitable for digital backs.
    BTW, the two Canon TSE lenses are also incredible free of distortion for a retrofocus design. Regarding this aspect Zeiss (18/21mm Distagons) and Rodenstock (HR-S/W wide angles) can still learn a lesson from their Japanese counterpart;-)
    Christoph

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    Re: wide lens IQ 180 shoot out: Digitar 28XL versus Digaron 32HR-W

    Quote Originally Posted by Stefan Steib View Post
    A "correction" of this kind of color cast in Software may result in a visible usable image file, but spoken from a point of lithography view, these files will give a hell of headaches to everybody trying to convert to CMYK -correct and print these in a qualitative way. [...] Ask any litho guy, he will tell you the truth about such files.
    Stefan, can you elaborate on this point?

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    Re: wide lens IQ 180 shoot out: Digitar 28XL versus Digaron 32HR-W

    There are 3 things still going for non-retrofocus lenses:

    1. Lack of distortion
    2. Lack of aberrations
    3. Size/weight (and thus lower cost)

    If retrofocus lenses can be designed so that they tick these 3 boxes then this will be a big step forward

    Canon seems to have (almost) cracked it with the 24mm (the 17mm is a bit too extreme IMO) but you can only use it on an HCam
    Yair Shahar | Product Manager | Phase One | Mamiya Leaf
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    Re: wide lens IQ 180 shoot out: Digitar 28XL versus Digaron 32HR-W

    This is complicated but OK-I´ll try to make a short one.
    Imagine the digital back as a signal to noise device. The most important part is getting a) best possible dynamics plus b) uniformity of this signal and c) getting a best match on the Luther condition (get as close to human color vision as possible).
    The better these conditions are met the more information is rendered. Now if I have to partially correct color casts the information given to the image rendition is lacking best possible conditions in 1,2 and 3. An electronic correction will result in differing internal color gradients (dynamically spoken a loss of steps available for color transformations) applying image corrections will result in differing output on equal colors, gradation corrrections will result in posterisations etc.pp.This may not be that visible on the first look, but if you need to adapt a file for a difficult print color transformation you will fail (or have at least a lot of fun and time spoiled using these files).

    I am sure a specialist science guy who is into image processing will be able to explain this with about 600 pages and formulas and maybe my shortening is to be discussed on several points because of simplification, but this is about it in a (well several) sentence(s).

    regards
    Stefan

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    Re: wide lens IQ 180 shoot out: Digitar 28XL versus Digaron 32HR-W

    Hi Yair

    I think the definitions could be very clear: If Dalsa or Kodak or all the other Chipmakers would release clear data about which angle, which light falloff and which center shift for these chips/parameters would be acceptable before a file gets visible color cast like the shown above, everybody could count 1+1=2.
    Rodenstock already quietly uses retrofocus designs (23mm) because they could not have built this lens otherwise ! And as it shows it is by far superior to the Schneider solutions available.
    Technology marches on. Companies who will not keep pace will be left behind.
    That simple.

    regards
    Stefan

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    Re: wide lens IQ 180 shoot out: Digitar 28XL versus Digaron 32HR-W

    But I do wonder is theree something afoot. If this is a practical in the field usage, http://cambouk.wordpress.com/2011/05...l-camera-back/

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    Re: wide lens IQ 180 shoot out: Digitar 28XL versus Digaron 32HR-W

    Quote Originally Posted by wentbackward View Post
    But I do wonder is theree something afoot. If this is a practical in the field usage, http://cambouk.wordpress.com/2011/05...l-camera-back/
    Hard to tell what's going on at the link in terms of the author's quality expectations, but it does raise the question of whether experience with the Leaf 80 meg back has been any different on issues of WA and shift color shifts.

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    Re: wide lens IQ 180 shoot out: Digitar 28XL versus Digaron 32HR-W

    Quote Originally Posted by Stefan Steib View Post
    A "correction" of this kind of color cast in Software may result in a visible usable image file, but spoken from a point of lithography view, these files will give a hell of headaches to everybody trying to convert to CMYK -correct and print these in a qualitative way. Of course if you only work for the internet or RGB that may get through somehow, but if I remember right, most of us are still getting their life paid by the printing industry products.

    Ask any litho guy, he will tell you the truth about such files.
    Stefan,

    This statement is completely lacking scale.

    It's very simple: CYMK conversion, moderate/severe Photoshop corrections, or large pre-processing adjustments (e.g. pushing shadow detail a stop) require there be reserve dynamic range and tonal smoothness in the file.

    Certainly for strong color casts the LCC uses up all of it's reserve dynamic range and tonal smoothness in the correction which means further adjustments (e.g. Photoshop or CYMK conversion, or shadow adjustments) will be straining the quality of the file.

    But for minor and moderate color casts, and digital back files shot at Low ISO I would very strongly say your statement is simply not true. The LCC process uses a small amount of the reserve of dynamic range and tonal smoothness in these cases. Further work such as Photoshop, CYMK conversion, or shadow adjustments will still have plenty of meat left.

    So I both strongly agree with you, and strongly disagree with you: depending on the scale. One cannot simply paint all color cast in the same light. Severe color cast is a major issue; light color cast is not (as dozens of photographers on this board can tell you from hands on experience).

    Given that most back/lens/movement combinations fall into the category of "light color cast" this is a very important distinction.

    Kudos however for developing a solution that allows the use of the 17TS/24TS (as well as your own shift optics and a good variety of other lenses) with a digital back. We had a chance to review the Hartblei Cam early in your release/marketing of it and at that point the Canon mount was not ready to ship so we have not had the chance to play with that element. But the build quality and overall functionality of the system was quite impressive.

    Doug Peterson (e-mail Me)
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    Last edited by dougpeterson; 23rd June 2011 at 05:43.

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    Re: wide lens IQ 180 shoot out: Digitar 28XL versus Digaron 32HR-W

    I shot quite extensively with the 28xl on the P65 and it the lens had much more room for correctable color cast.
    My though limited experience using the lens on the IQ180 made me come the conclusion that anything above 5mm on the long side renders the LCC corrected file almost "live less" where the massive blue cast was corrected for. I found extreme noise and loss of saturation.
    Woody raised an interesting point: how com that this issue was not reported ( to my knowledge) with the new Aptus.
    The only person I know of that owns both backs is Bryan Siebel in Dubai. I wonder if you could chime in if you read this.
    It would also be interesting if the IQ160 will have that same effect on color cast.
    I personally find the 28XL not usable / reasonably correctable with the IQ displaying such extreme color cast even unshifted is something I have never seen before .
    Too bad since I loved the lens before my upgrade which really begs for for an answer: what makes the IQ180 behave so differently compared to the P65?
    Just my 2c

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    Re: wide lens IQ 180 shoot out: Digitar 28XL versus Digaron 32HR-W

    Quote Originally Posted by rupho View Post
    what makes the IQ180 behave so differently compared to the P65?
    Same sensor size but with 20 million more pixels that are smaller and more tightly packed together has an impact on how the light hitting the sensor behaves.

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    Re: wide lens IQ 180 shoot out: Digitar 28XL versus Digaron 32HR-W

    I wonder if(?) the future of MFD turns out to be CMOS, whether those chips will have the same issues as MP's continue to rise as the present CCD's?

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    Re: wide lens IQ 180 shoot out: Digitar 28XL versus Digaron 32HR-W

    Quote Originally Posted by gazwas View Post
    I wonder if the future of MFD turns out to be CMOS, whether those chips will have the same issues as MP's continue to rise as the present CCD's?
    I wonder who actually needs more megapixels?

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    Re: wide lens IQ 180 shoot out: Digitar 28XL versus Digaron 32HR-W

    Terry, how are you finding your IQ180? I have to live vicariously: no whiff of mine yet!

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    Re: wide lens IQ 180 shoot out: Digitar 28XL versus Digaron 32HR-W

    What does need have to do with it?

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    Re: wide lens IQ 180 shoot out: Digitar 28XL versus Digaron 32HR-W

    Quote Originally Posted by tashley View Post
    Terry, how are you finding your IQ180? I have to live vicariously: no whiff of mine yet!
    Very simple and intuitive to use. I seem to use a combo of the touch screen and the buttons (old habits die hard). My fears with the 43XL haven't borne out and the LCC process seems to be really good. I still have a pretty big learning curve with the 180 on the tech camera coming from the P40+ since my focals and framing are different and the DOF is a little different.

    Focus mask really does work very well. My 43XL was giving me some focus fits but I worked out the calibration by doing some controlled testing (focus bracketing). I was 99% sure from the camera back masking which whould be the best shots and they were. All LCDs get harder to see in really bright light but the focus mask can't really be missed which is also good news.

    Bottom line is I would not trade back.

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    Re: wide lens IQ 180 shoot out: Digitar 28XL versus Digaron 32HR-W

    Doug
    as of any short answer may lead to misunderstandings - I said "this kind of color cast" - in this context the Schneider samples. We also agree that you can correct "some" colorcast with software getting "usable" files, whereas it is certainly better if there isn´t any. It is also quite important to see that tonal degradation will have a chance to be corrected in High bit(number of available color steps), whereas a strong color cast leads to an overall loss of dynamic range (signal to noise) as can be seen here.

    But actually I wonder that there were not stronger reactions to my first posting in this thread, I was nearly sure the Schneider troups would come to rescue the honour of the lens and tell me I am plain wrong......;-)

    Greetings from Munich

    Stefan

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    Re: wide lens IQ 180 shoot out: Digitar 28XL versus Digaron 32HR-W

    Hey,

    I wanted to thank Grischa and Yat for meeting me in Hong Kong. I had a great time and was happy that i could help you Grischa, to spend some more money :-P

    I knew that I would never use the 28mm with movments even before that after I saw a side by side comparsion at Arca Swiss. The color cast is so strong that it blows the channels and so captrure one just can't correct it. One can't correct someting if the data is missing.

    I can only say that I am extremly happy with my 32mm, I wanted to get the 28mm, but have to thank Arca and Schneider for telling me it would take 3-4 months longer than the 32mm for delivery.

    As I am still traveling I don't have the time i would like to have to post more tests and stuff but I will do that as soon as I am back home in july.


    A small off topic update. Phase One exchanged my IQ180 before I left and this one certainly is a lot better than the first one. Especially the damaged files are completly gone.

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    Re: wide lens IQ 180 shoot out: Digitar 28XL versus Digaron 32HR-W

    Quote Originally Posted by Stefan Steib View Post

    But actually I wonder that there were not stronger reactions to my first posting in this thread, I was nearly sure the Schneider troups would come to rescue the honour of the lens and tell me I am plain wrong......;-)

    Greetings from Munich

    Stefan
    Speaking personally as a die-hard Schneider "preferrer," I find it difficult to argue with your original statement -- the 28 is basically not a good match to the IQ180 unless you shoot it un-shifted. So you get no argument from me on your conclusion. Moreover, the first lens I ordered with my tech cam is the Rodenstock 40...
    Jack
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    Re: wide lens IQ 180 shoot out: Digitar 28XL versus Digaron 32HR-W

    Quote Originally Posted by Stefan Steib View Post
    Doug

    But actually I wonder that there were not stronger reactions to my first posting in this thread, I was nearly sure the Schneider troups would come to rescue the honour of the lens and tell me I am plain wrong......;-)

    Greetings from Munich

    Stefan
    There is none. The lens is great on paper. Small, wide, light, nearly no distorion, but it all fails on the IQ180. It does not help at all, when the color cast is so strong.

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    Re: wide lens IQ 180 shoot out: Digitar 28XL versus Digaron 32HR-W

    Quote Originally Posted by Jack Flesher View Post
    Speaking personally as a die-hard Schneider "preferrer," I find it difficult to argue with your original statement -- the 28 is basically not a good match to the IQ180 unless you shoot it un-shifted. So you get no argument from me on your conclusion. Moreover, the first lens I ordered with my tech cam is the Rodenstock 40...
    Great choice Jack, it is larger than the 43mm, but I am quite sure you will really like the lens.

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    Re: wide lens IQ 180 shoot out: Digitar 28XL versus Digaron 32HR-W

    Quote Originally Posted by Christopher View Post
    Great choice Jack, it is larger than the 43mm, but I am quite sure you will really like the lens.
    Thanks Christopher, but I am a bit concerned over the "more distortion" issue of the 40 compared to the 43...
    Jack
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    Re: wide lens IQ 180 shoot out: Digitar 28XL versus Digaron 32HR-W

    Quote Originally Posted by Stefan Steib View Post
    Doug
    as of any short answer may lead to misunderstandings - I said "this kind of color cast" - in this context the Schneider samples. We also agree that you can correct "some" colorcast with software getting "usable" files, whereas it is certainly better if there isn´t any. It is also quite important to see that tonal degradation will have a chance to be corrected in High bit(number of available color steps), whereas a strong color cast leads to an overall loss of dynamic range (signal to noise) as can be seen here.
    Ah, well in that case we are in complete agreement. Color casts as strong as the 28XL and an IQ180 with any shift (and even to some extent the last mm or two of the sides unshifted) is not fully-correctable, and whenever it can be corrected it will leave no reserve at all for further file-abuse.

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    Re: wide lens IQ 180 shoot out: Digitar 28XL versus Digaron 32HR-W

    Quote Originally Posted by Jack Flesher View Post
    Thanks Christopher, but I am a bit concerned over the "more distortion" issue of the 40 compared to the 43...
    I don't really think you have to be and there is always the Alpa Lens Cor. which does an amzing job.

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    Re: wide lens IQ 180 shoot out: Digitar 28XL versus Digaron 32HR-W

    Doug

    thank you for your compliments about the camera and lenses, this is a team work, without my partners in Kiev, Venice and Hamburg there would be none of the things we do and I was really lucky to find these guys. We also have to thank for the help of Phase/Mamiya/Leaf, Zeiss, Novoflex and some more, without their support and informations we could not have gone anywhere. Sometimes I am astonished how far we have already moved, if you would have told me 20 years ago we would become the last distributor of Zeiss MF lenses, I would have told you: come on get a nap and get normal.
    But it´s fun to play with the big boys !

    greetings from Munich
    Stefan

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    Re: wide lens IQ 180 shoot out: Digitar 28XL versus Digaron 32HR-W

    Quote Originally Posted by Christopher View Post
    I don't really think you have to be and there is always the Alpa Lens Cor. which does an amzing job.
    Yeah, but I'm running CS 64 bit, not 32, so would need another installation there to run the Alpa corrector -- a hassle factor. Also, how does the Alpa corrector handle shifts?
    Jack
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    Re: wide lens IQ 180 shoot out: Digitar 28XL versus Digaron 32HR-W

    Quote Originally Posted by Jack Flesher View Post
    Yeah, but I'm running CS 64 bit, not 32, so would need another installation there to run the Alpa corrector -- a hassle factor. Also, how does the Alpa corrector handle shifts?
    Start CS5 in 32bit mode.

    "cmd + i" the application icon and check "open in 32-bit mode". No need for another installation.

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    Re: wide lens IQ 180 shoot out: Digitar 28XL versus Digaron 32HR-W

    Jack, what ? You need to install it twice on macs ? Here on Windows I install it once and get both 32 and 64bit version installed. (CS4 and CS5) So for me, if i need to use the Alpa tool I just fire up the 32bit version instead of the 64bit and edit the image. After that i go back to 64bit. It's not perfect, but works quite good. Shifts are dialed in in mm. So you can add put in the excat movment you used. for example 7 up and 4 to the left. The tool does the rest. There are many more features and editing options, but that is getting complicated.

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    Re: wide lens IQ 180 shoot out: Digitar 28XL versus Digaron 32HR-W

    To clarify, I usually have CS5 open and running in 64 bit. So in order to use the Alpa corrector, ideally I would have a separate 32 bit installation -- CS4 is on my machine too, so that could maybe do it. Just seems a PITA, but at least it is a solution for now...

    Update: Okay, loaded the Alpa LC in CS4 and gave it a whirl. Seems pretty easy and intuitive, so problem solved -- THANK YOU! Stupid question though, on the correction folders, what is the difference between the P65 and P65SPM sets? Edit: Found SPM = Sensor Plus Mode

    I think a tiny white board to put in the frame for rise and shift may be in order
    Jack
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    Re: wide lens IQ 180 shoot out: Digitar 28XL versus Digaron 32HR-W

    Quote Originally Posted by Jack Flesher View Post
    Thanks Christopher, but I am a bit concerned over the "more distortion" issue of the 40 compared to the 43...
    Jack what made you choose the HR40 over the 43XL? Since you prefer Rodenstock. I made the opposite choice and got the 43xl
    Quote Originally Posted by Christopher View Post
    Great choice Jack, it is larger than the 43mm, but I am quite sure you will really like the lens.
    What is the verdict out here comparing the HR40 versus the HR50.cis there a clear winner?
    Quote Originally Posted by Christopher View Post
    Hey,

    I wanted to thank Grischa and Yat for meeting me in Hong Kong. I had a great time and was happy that i could help you Grischa, to spend some more money :-P

    My pleasure Christopher .
    A small off topic update. Phase One exchanged my IQ180 before I left and this one certainly is a lot better than the first one. Especially the damaged files are completly gone.
    Tell me about it I am on my third IQ180 now first One exposed only half the frame , then loaner and not it seems to work

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    Re: wide lens IQ 180 shoot out: Digitar 28XL versus Digaron 32HR-W

    Quote Originally Posted by Woody Campbell View Post
    Hard to tell what's going on at the link in terms of the author's quality expectations, but it does raise the question of whether experience with the Leaf 80 meg back has been any different on issues of WA and shift color shifts.
    Expectations is the key word here. We knew what to expect and we worked with these limitations in mind.

    Shooting those interiors required not more than a few mm rise on the horizontal frames and Leaf Capture's lens calibration tool handled it very well

    As a thumb rule I would say that if you see Blue towards the edges you know that you need to back off a bit.

    Also, in "emergency" you can use Sensorflex and set the back to shoot 60MP crop, doing away with the edges and giving you a bit more room for shifting (albeit making the lens a bit longer and the file a bit smaller)

    And with Live View if you use Sensorflex tethered WYSIWYG so framing is quite easy

    It's all about knowing the capabilities of your tools and planing the job properly IMO

    Yair
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    Re: wide lens IQ 180 shoot out: Digitar 28XL versus Digaron 32HR-W

    Quote Originally Posted by rupho View Post
    Jack what made you choose the HR40 over the 43XL? Since you prefer Rodenstock. I made the opposite choice and got the 43xl
    It was available sooner . Notwithstanding, it is a hair wider and closer to my "ideal" lens set formula.
    Jack
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    Re: wide lens IQ 180 shoot out: Digitar 28XL versus Digaron 32HR-W

    Quote Originally Posted by rupho View Post
    dear all,
    beware of the new Schneider 28mmXL Digitar on the IQ180.
    It got uncontrollable color cast EVEN WITHOUT SHIFT!
    Grischa, thank you for posting these tests. They are very interesting.

    This begs the question as to whether or not the Phase One 28mm lens will also exhibit similar color cast issues with the IQ180.

    Does anyone know if the Phase One 28mm lens will require LCC with the IQ180, and if so how well any color cast is corrected?

    David

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    Re: wide lens IQ 180 shoot out: Digitar 28XL versus Digaron 32HR-W

    Quote Originally Posted by David Klepacki View Post
    Grischa, thank you for posting these tests. They are very interesting.

    This begs the question as to whether or not the Phase One 28mm lens will also exhibit similar color cast issues with the IQ180.

    Does anyone know if the Phase One 28mm lens will require LCC with the IQ180, and if so how well any color cast is corrected?

    David
    No, it doesn't.
    Jack
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    Re: wide lens IQ 180 shoot out: Digitar 28XL versus Digaron 32HR-W

    Quote Originally Posted by Jack Flesher View Post
    No, it doesn't.
    +1 it does not
    Photography is all about experimentation and without it you will never learn art.

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    Re: wide lens IQ 180 shoot out: Digitar 28XL versus Digaron 32HR-W

    To super over simplify: It's all about the lens-to-sensor distance not the lens focal length. So the Phase One 28mm D which sits in front of a mirror box does not require LCC.

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    Re: wide lens IQ 180 shoot out: Digitar 28XL versus Digaron 32HR-W

    Thanks, that's what I would have expected.

    It is interesting that the Leica M9 does not have a mirror and their lenses sit really close to the sensor, much like the case of the Schneider 28XL in conjunction with the IQ180 in this thread. Somehow, Leica seems to be able to provide clean images even at the 16mm focal length of their Tri-Elmar lens, where the light rays hitting the sensor would be even more oblique than the case with the 28XL + IQ180 here.

    So, did Phase One simply overlook this technical issue in their design of the IQ180, as this customer Grischa seems to be the first one to discover it? Or, was there indeed a disclosure by Phase One on this matter when the IQ180 was announced?

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