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Thread: Comments on the P30/P30+ digital backs

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    Comments on the P30/P30+ digital backs

    I am reading lots of comments about the various 22 and 45mp backs, which I believe is due to their MF "full frame" sizes. The Phase One P30 and P30+ are a bit cropped. Also there is an AA filter, I think perhaps the others do not use one?

    At any rate, I would like to hear comments from some of the experienced photogs here regarding the pluses and minuses of these backs, and opinions vs. the 22 and 45mp's.

    I have started to use the Contax 645 with the P30+, and clearly still have much to learn, so I am not one to be giving advice.

    Others?

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    Senior Member irakly's Avatar
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    Re: Comments on the P30/P30+ digital backs

    the main reason why i opted for the P25 was not really a slightly larger frame size (the difference is nearly unnoticeable), but the fact that P26 has larger pixels and do not use microlenses. it is microlenses that cause lateral colour shifts, especially when used with tilt/shift lenses and bellows. since a large chunk of my commercial work is things like watches and fragrance bottles, contax bellows is not a toy for me, but a tool of greatest importance. i also figured out how to use it for portraiture, which made it even more usable and the issue of the colour offset even more pressing. that's why P25.

  3. #3
    thsinar
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    Re: Comments on the P30/P30+ digital backs

    The use of micro-lenses on a sensor makes it impossible/difficult to use with a view camera with tilts/swings/shifts or with short focal length lenses and leads to very serious color shifts, when the light hits the pixels with an angle and not "straight.

    Also smaller pixels have in addition the negative effect/disadvantage that the dynamic range (DR) is much smaller, that those pixels are faster "full", thus leading very quickly to over-exposure. Also, significant details in the shadows get lost.

    Best regards,
    Thierry

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    Re: Comments on the P30/P30+ digital backs

    Quote Originally Posted by thsinar View Post
    The use of micro-lenses on a sensor makes it impossible/difficult to use with a view camera with tilts/swings/shifts or with short focal length lenses and leads to very serious color shifts, when the light hits the pixels with an angle and not "straight.

    Also smaller pixels have in addition the negative effect/disadvantage that the dynamic range (DR) is much smaller, that those pixels are faster "full", thus leading very quickly to over-exposure. Also, significant details in the shadows get lost.

    Best regards,
    Thierry
    OK, can't use it with tilt/shift.

    I already have understanding of the general effects of smaller pixels. Is this effect apparent with these backs when compared to the 22 and 45 mps? Also, I believe the 45mp backs have similarly sized or smaller pixels so this would suggest any general effect would be worse with 45mp backs.

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    Subscriber gogopix's Avatar
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    Re: Comments on the P30/P30+ digital backs

    Quote Originally Posted by irakly View Post
    the main reason why i opted for the P25 was not really a slightly larger frame size (the difference is nearly unnoticeable), but the fact that P26 has larger pixels and do not use microlenses. it is microlenses that cause lateral colour shifts, especially when used with tilt/shift lenses and bellows. since a large chunk of my commercial work is things like watches and fragrance bottles, contax bellows is not a toy for me, but a tool of greatest importance. i also figured out how to use it for portraiture, which made it even more usable and the issue of the colour offset even more pressing. that's why P25.

    Have you used the auto bellows for macro work? I wondered whether the AF really worked (no reason it shouldnt except very narrow DOF could cause a lot of hunting in some scenes.

    anyway, I would almost always use MF but nice to know if the auto is for exposure only or if AF also works.

  6. #6
    DougDolde
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    Re: Comments on the P30/P30+ digital backs

    Biggest drawback as I see it of a P30 on a Contax 645 is that the widest lens is 35mm, unlike the Fujiblad and Mamiya which both have a 28mm. That mitigates the smaller sensor for sure. But you can pan-stitch, just not shift stitch.

    A friend of mine tried his P30 on a Cambo Wide, stitching with a 35mm Digitar. The color shifts made it pretty near impossible to get good results. He's considering getting another back just for that purpose. Ka-Ching !

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    Re: Comments on the P30/P30+ digital backs

    Tom,

    I have used both the P30+ and the Sinar eMotion 75LV with the Contax 645.

    First, I specifically tested for dynamic range of these two backs. The result was identical. Neither back showed advantage/disadvantage in this area.

    It is true that any kind of strong shifting and tilting of the lenses cause color shifts with the P30+, but on the Contax 645 it only happens when using the auto bellows. Otherwise, I found the Phase P30+ to be outstanding, especially for its rendition of skin tones. You don't have to take my word for this though. Just check out the portrait work of James Russell who uses the P30+ on his Contax.

    As for the Sinar back? Their color rendition is gorgeous, and not that much unlike the P30+. But remember, the perception of color is also highly subjective, so this is only my opinion. I now prefer the Sinar back mostly for other reasons stated elsewhere in other threads here.

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    Subscriber gogopix's Avatar
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    Re: Comments on the P30/P30+ digital backs

    yes, that's why the P25 really sings with the 35mm

    also a 30mm hasselblad....

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    Re: Comments on the P30/P30+ digital backs

    Quote Originally Posted by DougDolde View Post
    A friend of mine tried his P30 on a Cambo Wide, stitching with a 35mm Digitar. The color shifts made it pretty near impossible to get good results. He's considering getting another back just for that purpose. Ka-Ching !
    Is this pano stitch or shift stitch? Sorry not familiar with this lens but from your comments I assume it's a shift lens.

    I don't intend to do shift stitching at this point, but thanks for this info. It's exactly the sort of info that has practical importance.

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    Re: Comments on the P30/P30+ digital backs

    Quote Originally Posted by tom in mpls View Post
    OK, can't use it with tilt/shift.

    I already have understanding of the general effects of smaller pixels. Is this effect apparent with these backs when compared to the 22 and 45 mps? Also, I believe the 45mp backs have similarly sized or smaller pixels so this would suggest any general effect would be worse with 45mp backs.
    The 22MP backs are still the sweet spot in terms of price/performance in MFDB. Victor has some shots with a P25 that you would be hard-pressed to tell from a P45+. I think the colors on all the 9um backs are exceptional, and have not personally come across any "bad" ones. On the other hand, you are more exposed to higher degrees of moire with the larger pixels.

    Also, Doug makes a good point. A larger overall chip size will be able to take as much advantage of your wide angle as possible, so that is also something that you need to consider.

  11. #11
    thsinar
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    Re: Comments on the P30/P30+ digital backs

    certainly a camera shift, with the 35mm digitar, otherwise there would be no shift: shifting in the image circle of the lens leads to the light rays hitting the sensor in a more oblique angle, thus creating those color shifts which are very difficult/impossible to get rid of.

    It has to be said that these color shifts can happen as well with a very short focal length: the shorter the lens, the shorter the distance lens plane/sensor plane, the bigger the angle at which the light rays hit the sensor.

    Thierry

    Quote Originally Posted by tom in mpls View Post
    Is this pano stitch or shift stitch? Sorry not familiar with this lens but from your comments I assume it's a shift lens.

    I don't intend to do shift stitching at this point, but thanks for this info. It's exactly the sort of info that has practical importance.

  12. #12
    thsinar
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    Re: Comments on the P30/P30+ digital backs

    I fully agree, David.

    Thierry

    Quote Originally Posted by David Klepacki View Post
    The 22MP backs are still the sweet spot in terms of price/performance in MFDB. Victor has some shots with a P25 that you would be hard-pressed to tell from a P45+ in terms of resolution. I think the colors on all the 9um backs are exceptional, and have not personally come across any "bad" ones. On the other hand, you are more exposed to higher degrees of moire with the larger pixels.

    Also, Doug makes a good point. A larger overall chip size will be able to take as much advantage of your wide angle as possible, so that is also something that you need to consider.

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    Senior Member irakly's Avatar
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    Re: Comments on the P30/P30+ digital backs

    Quote Originally Posted by gogopix View Post
    Have you used the auto bellows for macro work? I wondered whether the AF really worked (no reason it shouldnt except very narrow DOF could cause a lot of hunting in some scenes.

    anyway, I would almost always use MF but nice to know if the auto is for exposure only or if AF also works.
    4/120 is a manual focus lens
    to be honest with you, i rarely use AF. never crossed my mind to use it with bellows mainly because whatever needs to be in focus is not in the centre of a frame. it is easier to focus manually than to reposition the bellows.

  14. #14
    DougDolde
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    Re: Comments on the P30/P30+ digital backs

    Quote Originally Posted by tom in mpls View Post
    Is this pano stitch or shift stitch? Sorry not familiar with this lens but from your comments I assume it's a shift lens.

    I don't intend to do shift stitching at this point, but thanks for this info. It's exactly the sort of info that has practical importance.
    Not a shift lens with the Cambo. The lens doesn't move; you shift the back.

    Pan stitching you can do with your Contax/P30. Just rotate the camera taking overlapping shots. Preferably with a leveled camera, on a tripod, and the nodal point of the lens over the pivot point.

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    Re: Comments on the P30/P30+ digital backs

    Quote Originally Posted by DougDolde View Post
    Not a shift lens with the Cambo. The lens doesn't move; you shift the back.
    Cool. Hooda thunkit? Same optical effect (and problems) as a shift lens, then.

    Pan stitching you can do with your Contax/P30. Just rotate the camera taking overlapping shots. Preferably with a leveled camera, on a tripod, and the nodal point of the lens over the pivot point.
    Yup, I am familiar with the pano techniques.

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    Re: Comments on the P30/P30+ digital backs

    Quote Originally Posted by gogopix View Post
    yes yes, and I have the 120 as well, However I also have every other lens and was cusrious whether the elctronicsa worked the AF as well as the AE.

    I only asked since I bought the bellows used and do not have the manual.

    Regards
    Victor
    The Contax Autobellows is indeed capable of both AE and AF. However, if you do not have enough light/contrast, it will continue to hunt for focus. Your best bet for AF is the 80/2 and enough light... but like Irakly says, you will most likely end up manually focusing.

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    Re: Comments on the P30/P30+ digital backs

    Quote Originally Posted by David Klepacki View Post
    The Contax Autobellows is indeed capable of both AE and AF. However, if you do not have enough light/contrast, it will continue to hunt for focus. Your best bet for AF is the 80/2 and enough light... but like Irakly says, you will most likely end up manually focusing.

    David that's what I assumed, that the AF part of the C would just hunt. Also, with so much Leica being my other systems I have come to use MF by default.

    The one area that could use improvement is the AF in the C645. That is why I am considering an alternate AF system; Looking at Hasselblad H or the Rollei/Hy6.

    I notice you use the Sinar and Phase, yet seem happy with both. I am considering a sinar as backyup rather than another Phase (thinking P30+ since it favours tele shots being a crop sensor.
    After I get my questions down I will like start a thread on MF AF alternatives.

    as these soon to be 66 YO eyes further need correction, MF and diopter corrections are getting to be a problem (up to -5 diopter!)

    Anyway, David, if you could comment on Sinar esp 22 vs 31 (33?) MP it would help my settling at least on the back (with Sinar I would then have the option for both Contax and "OTHER AF system" use.

    thx
    Regards
    Victor

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    Re: Comments on the P30/P30+ digital backs

    Quote Originally Posted by gogopix View Post
    I notice you use the Sinar and Phase, yet seem happy with both. I am considering a sinar as backyup rather than another Phase (thinking P30+ since it favours tele shots being a crop sensor.
    After I get my questions down I will like start a thread on MF AF alternatives.

    as these soon to be 66 YO eyes further need correction, MF and diopter corrections are getting to be a problem (up to -5 diopter!)

    Anyway, David, if you could comment on Sinar esp 22 vs 31 (33?) MP it would help my settling at least on the back (with Sinar I would then have the option for both Contax and "OTHER AF system" use.

    thx
    Regards
    Victor
    Well, in previous posts, I think that I have made my case about the Sinar back as being the best solution for me, and I hoped that my experiences would help others with their, quite serious, investment choice. To recap the primary advantages of the Sinar backs:
    - very high quality adapter plates for ALL MF cameras (even new Phase model), so you are not locked into one system.
    - open workflow with DNG files (can use C4, Lightroom, ACR, etc.), so workflow can be same regardless of camera system
    - no sacrifice in image quality (resolution, color and dynamic range are tops)

    I also chose the Hy6 as my leaf shutter system for the following reasons:
    - support for future square sensors (Hasselblad H cameras are dead end in this respect)
    - 645 revolving adapter is extremely convenient (no more rotating your entire camera between landscape and portrait shots)
    - interchangeable viewfinders (WLF and 90-degree)
    - very lightweight, like Contax (Hasselblad H3Dxx is the heaviest MF system you can buy....which really stresses your hands....especially if you have to rotate the entire camera from portrait to landscape.)
    - highest flash sync available (1/1000)
    - tilt/shift lens available (nothing for Hasselblad H offers tilt)
    - fast and accurate AF (just as fast as the Hasselblad H3D)

    As for 22MP versus 33MP .... now that is a more difficult question (I have both from Sinar). I have to be honest here, and will say that moire does crop up in the 22MP back. And, for as yet to be explained, I have not seen any moire with my 33MP back. I know physically it should still be there, but so far nothing. The image quality and especially color fidelity are just so high for BOTH these backs, that my recommendation would be that either back would work for you. Since you have owned and liked the P25, I would say that your experience with the Sinar 22MP back should be just as pleasing.
    Last edited by David Klepacki; 19th April 2008 at 17:29.

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    Re: Comments on the P30/P30+ digital backs

    A few more comments on 22 versus 33.

    I would say that there should be a difference when printing really large. My printer only has a 24-inch width, so I have not been able to push the print size to see where the 22MP back starts to break down in noticeable quality.

    Of course, the extra pixels of the 33MP also means more freedom in cropping. Sometimes, when shots must be taken quickly, you just have to mount your wide and hope for the best with cropping later.

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    Re: Comments on the P30/P30+ digital backs

    David

    Thank, extremely helpful. On the rotating back, is that an additional item, so ALL camera adapters work or do you need a special "Contax rotation back adapter" and one for each other

    these guys are expensive (though a LOT cheaper than an extra back!

    Victor

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    Re: Comments on the P30/P30+ digital backs

    Quote Originally Posted by David Klepacki View Post
    And, for as yet to be explained, I have not seen any moire with my 33MP back. I know physically it should still be there, but so far nothing.
    I think the 33mp has AA filter so no moire, but no AA on the 22mp. Correct me if I am mistaken.

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    Re: Comments on the P30/P30+ digital backs

    I borrowed a friend's P30 to photograph some moire-prone organza fashion, but an Aptus 75 did better.

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    Re: Comments on the P30/P30+ digital backs

    Quote Originally Posted by gogopix View Post
    David

    Thank, extremely helpful. On the rotating back, is that an additional item, so ALL camera adapters work or do you need a special "Contax rotation back adapter" and one for each other

    these guys are expensive (though a LOT cheaper than an extra back!

    Victor
    First, only the square format cameras (e.g., Hasselblad V, Rollei 6008, Sinar Hy6) are capable of rotating adapters. This is one huge advantage of the Sinar system for square format cameras, even though shooting with a 645 format sensor. Unfortunately, you cannot rotate the back on the Contax.

    Second, I should point out that while Sinar offers these rotating backs, they also have a special "revolving" adapter exclusively for the Sinar Hy6. The advantage here is that the back does not get removed from the camera, and can easily be rotated from portrait to landscape and vice-versa by just twisting. With the rotating adapters, you have to physically unmount the back, rotate it, and then re-mount it....also very fast and not much effort as it may sound.

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    Re: Comments on the P30/P30+ digital backs

    Quote Originally Posted by tom in mpls View Post
    I think the 33mp has AA filter so no moire, but no AA on the 22mp. Correct me if I am mistaken.
    There is no AA filter on any of the Sinar backs.

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    Re: Comments on the P30/P30+ digital backs

    Quote Originally Posted by David Klepacki View Post
    There is no AA filter on any of the Sinar backs.
    OK. Is that also true for Phase?

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    Re: Comments on the P30/P30+ digital backs

    P21(+) & P30(+) have microlenses.

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    Re: Comments on the P30/P30+ digital backs

    Quote Originally Posted by BJNY View Post
    P21(+) & P30(+) have microlenses.
    I guess I need more info on what microlenses are for/what they do, and how it it is different from an AA filter. Can someone educate me?

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    Re: Comments on the P30/P30+ digital backs

    Quote Originally Posted by tom in mpls View Post
    I guess I need more info on what microlenses are for/what they do, and how it it is different from an AA filter. Can someone educate me?
    In a nutshell, microlenses are used to boost signal sensitivity by capturing light that would otherwise be lost due to oblique incidence on the sensor (between the pixels). Typically, there is a tiny microlens over each pixel, sort of like a catcher's mit. However, there is a limit to how oblique these lenses will be able to catch the light without distorting the wavelength information. Beyond this angle, false colors appear. In my baseball analogy, it would like calling a wild knuckle-ball a strike, even though it did not go over the plate.

    For a photo example, if you use an ultra-wide lens on a rangefinder camera (e.g., a 24mm lens on an Alpa), the oblique impact of the light could cause color shifts if the sensor uses microlenses, that you would have to correct manually. Similar situations occur when using large enough tilt and shift movements on a technical camera.

    An AA filter is used to suppress the spatial frequencies that exceed the sampling limit of the sensor (known as the Nyquist rate). The Nyquist frequency is determined by the size and spacing of the pixels. In general, the smaller the pixels and more densely they are packed results in higher Nyquist frequencies. In photographic terms, if your image contains very fine detail that exceeds the ability of the sensor to capture such resolution, those frequencies get recorded with false colors and structures, also referred to as moire. Sort of like if your car odometer exceeds its number of digits, the mileage would go back to counting from zero, since there is no place to record those extra miles. Similarly, these high frequencies have no where to go, so get falsely recorded by the sensor, when no AA filter is present.

    An AA filter essentially blurs these high frequencies into the higher frequency capabilities of the sensor, but this leads to some loss of the sensor resolution, which is why many people do not like them.

    Lastly, some cameras contain both microlenses and an AA filter. They are two things used for two different purposes.
    Last edited by David Klepacki; 21st April 2008 at 09:15. Reason: spelling corrections

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    Re: Comments on the P30/P30+ digital backs

    Quote Originally Posted by tom in mpls View Post
    OK. Is that also true for Phase?
    Yes. Phase does not use AA filters on any of their backs.

    To my knowledge, the only MF backs that have AA filters are the older Kodak backs (discontinued) and the Mamiya ZD back. In each case, these AA filters are optional (removable).

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    Re: Comments on the P30/P30+ digital backs

    Quote Originally Posted by David Klepacki View Post
    Yes. Phase does not use AA filters on any of their backs.

    To my knowledge, the only MF backs that have AA filters are the older Kodak backs (discontinued) and the Mamiya ZD back. In each case, these AA filters are optional (removable).
    Obviously I was getting confused between AA filters and microfilters. Thanks!

  31. #31
    thsinar
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    Re: Comments on the P30/P30+ digital backs

    just some more information about microlenses:

    Microlenses are also used to gain sensitivity, which is reduced with smaller pixels.

    Smaller pixels have in addition the negative effect/disadvantage that the dynamic range (DR) is much smaller, that those pixels are faster "full", thus leading very quickly to over-exposure. Also details in the shadows get lost.

    Thierry

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    Re: Comments on the P30/P30+ digital backs

    Quote Originally Posted by tom in mpls View Post
    Obviously I was getting confused between AA filters and microfilters. Thanks!
    Umm, make that "microlenses".

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    Member Clawery's Avatar
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    Re: Comments on the P30/P30+ digital backs

    Here are a few PDFs of the P30+ and P45+. Let me know what other information you might need.

    Chris Lawery
    Sales Manager
    [email protected]
    Capture Integration, Phase One Dealer of the Year

    877-217-9870 | National
    404-234-5195 | Cell
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