P40+ vs. P45+

[danlindberg]

The back will be used exclusively on a tech camera for architecture. Are both backs suitable for shift/tilt/swing?

I understand that P40+ is a cropped senser, meaning a wide is not quite as wide but with increased possibilities with movements, right?
I have read somewhere about microlenses, is this a problem with this back and movements?

Bottomline, which one of these would you choose with a tech camera for interiors and exterior architecture?

 

[gazwas]

IMO the choice boils down to if you can live with the crop of the P40+ and have your lenses not as wide. The obvious solution if you went P40+ is just buy wider glass but with LF lenses, the wider you go the more the price climbs and bigger and heavier and more distortion the lens gets.

On a P40+, a LF Schneider/Rodenstock 35mm lens (22mm equivalent on 35mm) actually becomes a 43mm (28mm equivalent on 35mm) but still has all the distortion, light falloff, size, weight and flange to focal distance issues of a wider lens.

Personally I would go P45+ for interiors and architecture but make sure you use retrofocus wide angle lenses from Rodenstock to avoid the greater colour shifts the P45+ sensor displays (that can be corrected in C1) over the Dalsa chipped P40+.

The ideal for architecture is full frame but that another price jump. :bugeyes:

 

[danlindberg]

Great information about lens choice!

I frequently read that the main investment should be going into the DB. I reason differently where I strongly believe that it is the very best lenses that should be on priority. The two first lenses I have on my wishlist is Schneider Super Digitar 28XL and the Schneider Apo Digitar 43XL. Both with great possibility for movements. Yes, expensive, but here I do not want to compromise. I rather buy these and a lesser DB than the other way around.

Would you say those lenses are a good match for any DB? The 28, as I understand it, corresponds to a 22 in 35 terms and this is ok for width with a cropped sensor.

I just saw a second hand P45+, 3 years old, for 7 000 euros closeby where I live in Sweden (mounted on a Hasselblad H2). It does not say how many actuations. Dangerous buy?

 

[gazwas]

The two lenses you mention should work fine but I would also strongly consider looking at the Rodie 40HR-W if you go P45+ as it has a larger flange to focal distance and may result is less LCC issues. Remember, the more LCC you have to apply in C1, the less DR your getting in your captures.

Don't know much about the SK 28mm as its so new and very few people have used one. From what I've read on various forums is that it has a very steep fall off in illumination and you can only correct this digitally. This might somewhat limit it's movements ability. Possibly a slightly less wide but better fall off might be better. However, on a P45+ the 28mm is equivalent to a 20mm in a 35mm lens so possibly too wide for architecture(?).

One thing to consider if your open to stitching shots is the P40+ (Dalsa chip) will probably do this a little better than the P45+, again due to LCC issues with the Kodak chip.

Regarding the P45+ you've seen, personally I would not but a Phase back in anything other than Mamiya/Phase mount today. The H system has been closed to Phase and all the new good stuff like a new Phase camera and Schneider/Phase/Mamiya LS lenses will all be the Phamiya mount. I know you said the back is exclusive to a tech camera but I wouldn't limit you choices if a job calls for more flexibility in the future.

 

[GrahamWelland]

Don't know much about the SK 28mm as its so new and very few people have used one. From what I've read on various forums is that it has a very steep fall off in illumination and you can only correct this digitally. This might somewhat limit it's movements ability.

Gareth,

I think you are mistaken regarding movement limitations here. The SK 28mm has one of the largest images circles available, especially considering it's a 28mm lens with 90mm!! That's more movement than pretty much anything else available from anyone until you get to the 43/47mm lenses.

 

[gazwas]

Gareth,

I think you are mistaken regarding movement limitations here. The SK 28mm has one of the largest images circles available, especially considering it's a 28mm lens with 90mm!! That's more movement than pretty much anything else available from anyone until you get to the 43/47mm lenses.

What I should have said is that due to there being no glass centre filter the only option is digital correction with this lens. While I appreciate it has a very large IC for a 28mm lens, how much of that is actually useable is still under question for me.

From what little I've read from limited users the fall off is about 4 stops with any sort of meaningful (architecture) movement and digital correction at that level just produces noise IMO and hence my advise to possibly consider a little less wide lens.

So while on paper, yes its amazing, however I wouldn't buy one blind if you need any sort of shifts or rise/falls from this lens.

 

[GrahamWelland]

What I should have said is that due to there being no glass centre filter the only option is digital correction with this lens. While I appreciate it has a very large IC for a 28mm lens, how much of that is actually useable is still under question for me.

From what little I've read from limited users the fall off is about 4 stops with any sort of meaningful (architecture) movement and digital correction at that level just produces noise IMO and hence my advise to possibly consider a little less wide lens.

Well, I'd certainly agree about the optical centre filter. At extreme shifts I've seen the effect of LCC correction noise even with my 47 XL APO-Digitar and would consider a real filter for it if I needed that level of movement regularly. For a wider lens I agree that centre filters are the way to go.

 

[rhsu]

Dan,

I'm in agreement with Gareth above re P45+. I have used it extensively with tech camera. Although the P40+ has the new generation of micro lenses (ie allowing greater angle of incident light than the 1st generation) thus able to be used with tech camera, but you must be careful and keep in mind when you intend to push the DB and lens with large IC to the max. P40+ is a 6micron pitch pixel and P45+ is 6.8micron pitch. The former can be unforgiving ie pixel diffraction. Good luck...