Comments on the P30/P30+ digital backs

[tom in mpls]

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?

 

[irakly]

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.

 

[thsinar]

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

 

[tom in mpls]

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.

 

[gogopix]

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.

 

[DougDolde]

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 !

 

[David Klepacki]

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.

 

[gogopix]

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

also a 30mm hasselblad....:toocool:

 

[tom in mpls]

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.

 

[David Klepacki]

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.

 

[thsinar]

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

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.

 

[thsinar]

I fully agree, David.

Thierry

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.

 

[irakly]

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 :ROTFL::ROTFL::ROTFL:
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.

 

[DougDolde]

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.

 

[tom in mpls]

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.

 

[David Klepacki]

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.

 

[gogopix]

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

 

[David Klepacki]

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.

 

[David Klepacki]

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.

 

[gogopix]

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