The GetDPI Photography Forum

Great to see you here. Join our insightful photographic forum today and start tapping into a huge wealth of photographic knowledge. Completing our simple registration process will allow you to gain access to exclusive content, add your own topics and posts, share your work and connect with other members through your own private inbox! And don’t forget to say hi!

44x33mm vs 48x36mm digital backs

timn420

New member
I'm looking at picking up an older P25 phase one or P30 and was wondering if you lose some of the MFD look by buying a cropped sensor back?

I shoot a lot of portraiture wide open and really like trying to get as soft background as possible. I like the p30, but I'm worried that I might lose some of the "look" by buying it over the P25.

Is this a concern or is the crop difference between the two negligible?
 

Digitalcameraman

Active member
Tim,

The images will not look any different regarding the physical size of the image. The lens will still compress the image and the background will go out of focus the same. If anything, you are using the best part of the lens.

Now the P25 is an older sensor than the P30 sensor. Both are Kodak Sensors both produce great images in their own category.

I found the biggest difference was the size of the pixels. The P30 has smaller pixles so we see much less morie and color aliasing and in my opinion would be a better fit for people with clothing. We saw alot of this on blue jeans, ties, sport coats. Much of it can be controlled by stopping the lens down to a smaller opening.

On landscape and hard line items such as products ect, the P25 was a great performer.

The P30/P45 were made from similar sensors except the P30 had microlenses on the sensor to allow for higher ISO. This was not good for technical cameras or view cameras.

The P25 used "fat" pixels that many liked and at the time it was a great imaging tool. Sure the P25 sensor is physically larger but that requires your lens to be better on the edges.

The + versions of those camera backs were also different.
P25+/P30+/P45+ allowed for up to an hour exposure, had a bigger RAM buffer, so shooting tethered was better, and had an improved rear preview screen.

P21/P30 has a crop factor of 1.3x
P25/P45 has a crop factor of 1.1x

Good luck.










I'm looking at picking up an older P25 phase one or P30 and was wondering if you lose some of the MFD look by buying a cropped sensor back?

I shoot a lot of portraiture wide open and really like trying to get as soft background as possible. I like the p30, but I'm worried that I might lose some of the "look" by buying it over the P25.

Is this a concern or is the crop difference between the two negligible?
 

kdphotography

Well-known member
Chris probably just put together the most succinct list of differences between the P25 and P30 that I've seen. :)

That being said, the P30 was one of my favorite, easy to use, MFDBs. It is great for moving quickly and getting the shot. Great images right out of the box. Once you get up to the P65+, you really need to slow down a bit and take more care. The slight crop of the P30 sensor also means you will be able to take advantage of most all the available lenses.

:)ken
 

Shashin

Well-known member
There is not a lot of difference in the size. I use both size sensors--p25+ and 645D. Size should not be the deciding factor. There is no real difference in the look.

The image circles are so close that lens performance is not an issue either.

The only real difference would be the micro lenses. If you want this back for a view camera or tech cam, then the p25 would be better.
 
I very recently wandered into the MFDB world (hence this being my first post here on GetDPI) and bought a P30+ on a Phase One 645DF back, with numerous lenses. Coming from years of fullframe 35mm sensors from 1DX, 5D3, 6D etc., I have long been searching for that "look" that my grandfathers old Rolleiflex gave me, the extremely shallow DOF yet subject almost entirely in focus. Personally I'm more of a landscape guy and I would have picked a P25/P45/P65 if I had the choice, but the price I paid for the P30+ kit was so low I dare not speak it out loud, so I made the jump, because it was offered to me locally and where I live, MFDB's are a rarity to say the least.

I don't shoot portraiture professionally, mostly snaps of my own family, but here are a few unprocessed full-resolution full-size demos from the P30+ sensor:

A cheapo ~$100 Mamiya 150mm f/3.5N gives ridicilous value for money wide-open:
https://dl.dropboxusercontent.com/u/80257/phaseone/CF040332.jpg

Relatively cheap Mamiya 210/4 ULD as well:
https://dl.dropboxusercontent.com/u/80257/phaseone/CF039951.jpg

Schneider-Kreuznach 80/2.8 LS, expensive but worth every cent:
https://dl.dropboxusercontent.com/u/80257/phaseone/CF039740.jpg

I'm head over heels in love with my P30+. Going back to my current Canon 6D feels like a huge step back in image quality. It's just not about the resolution, but the colors !!! Oh the colors!!
 

dougpeterson

Workshop Member
There is not a lot of difference in the size. I use both size sensors--p25+ and 645D. Size should not be the deciding factor. There is no real difference in the look.
I do not agree with this.

For those who want very shallow DOF the look of a 110/2.8 or the 80/1.9 or Contax 80/2 etc on a full frame digital back can NOT be matched by a crop sensor (e.g. P30+ or 645D).

It's also fair to say that either way you'll end up with shallow DOF and the ability to make amazing images. But if you like to push the limit of shallow DOF and love bokeh then a full frame sensor or 1.1 crop sensor will provide something that a 1.3 crop cannot.

It's similar to comparing a [7D+50/1.2] to a [5D+50/1.2] except that the Schneider 110LS is actually sharp wide open :).
 

Shashin

Well-known member
I do not agree with this.

For those who want very shallow DOF the look of a 110/2.8 or the 80/1.9 or Contax 80/2 etc on a full frame digital back can NOT be matched by a crop sensor (e.g. P30+ or 645D).

It's also fair to say that either way you'll end up with shallow DOF and the ability to make amazing images. But if you like to push the limit of shallow DOF and love bokeh then a full frame sensor or 1.1 crop sensor will provide something that a 1.3 crop cannot.

It's similar to comparing a [7D+50/1.2] to a [5D+50/1.2] except that the Schneider 110LS is actually sharp wide open :).
Well, I don't agree with your statement either. Especially since both the 110mm and 80mm lenses you cite would actually have less DOF on the 33x44mm sensor compared to the 48x36mm and a lot less than a full-frame MFD sensor. As sensor size decreases with any given focal length for any given aperture, DOF decreases.

Like I said, I speak from experience--a couple of mm difference is not that big a deal. And if you want a shallower DOF with your MF lenses, then go with the smaller sensor if you think it is significant.
 
Last edited:

dougpeterson

Workshop Member
Well, I don't agree with your statement either. Especially since both the 110mm and 80mm lenses you cite would actually have less DOF on the 33x44mm sensor compared to the 48x36mm and a lot less than a full-frame MFD sensor. As sensor size decreases with any given focal length for any given aperture, DOF decreases.

Like I said, I speak from experience--a couple of mm difference is not that big a deal. And if you want a shallower DOF with your MF lenses, then go with the smaller sensor if you think it is significant.
If you frame a particular shot (e.g. head and shoulders) using a 110LS and a full frame sensor, and frame the same shot using a 110LS using a 1.3 crop sensor (i.e. by stepping back) the ears and background will be more out of focus in the full-frame sensor shot.

In other words if you want to produce a headshot with the most "pop" due to the eyes being sharp and the ears/rest-of-scene being very blurred, then you want the biggest sensor you can get.
 

Ken_R

New member
Well, I don't agree with your statement either. Especially since both the 110mm and 80mm lenses you cite would actually have less DOF on the 33x44mm sensor compared to the 48x36mm and a lot less than a full-frame MFD sensor. As sensor size decreases with any given focal length for any given aperture, DOF decreases.

Like I said, I speak from experience--a couple of mm difference is not that big a deal. And if you want a shallower DOF with your MF lenses, then go with the smaller sensor if you think it is significant.
Given equal focal length, subject and composition/framing you will be a bit closer with the larger sensor camera and hence get a bit shallower DOF.

Again, given equals, with the smaller sensor cam you need to step back a bit to get an equal composition.

The larger the sensor, the larger the difference. Again dunno why it's even an argument since most here have PLENTY of experience with this.
 

Paul2660

Well-known member
BYW. It's a bit more than stepping back a few steps. With a 60mm i found the distance was more like 12 feet to get the same framing shot first taken with full frame then trying to capture about the same subject matter with a cropped sensor. Depending on location and subject matter this can become problematic.

Paul
 
At the risk of sounding trite, you just need to try them both. For photographing people, the P30+ is a great back, partly because it doesn't feel slow. Were I choosing between a P25 and a P30+ for portraits, I would go with the P30+ for all the reasons that Digitalcameraman listed.

Now, I have never shot a P30+ and P25 side by side as Doug and Digitalcameraman undoubtedly have, but shooting an 40 MP and 80 MP side by side in a studio, I was amazed at the difference in look, and also how hard it was to get the 80 MP shot in critical focus. Whether this translates to the lower megapixel backs, I can't say. My guess is that difference still holds at some level with the backs you are considering, but I think there are bigger differences that will ultimately make your decision.
 

jlm

Workshop Member
don't know your camera system, but the hasselblad CFV-I and II (1.3 crop, 16mpx) and the Phase P20( same px and crop) both are offered in square format for use with the Hasselblad V or the Rollei 6008 series, both of which offer great lenses in their lineups
 

Shashin

Well-known member
If you frame a particular shot (e.g. head and shoulders) using a 110LS and a full frame sensor, and frame the same shot using a 110LS using a 1.3 crop sensor (i.e. by stepping back) the ears and background will be more out of focus in the full-frame sensor shot.

In other words if you want to produce a headshot with the most "pop" due to the eyes being sharp and the ears/rest-of-scene being very blurred, then you want the biggest sensor you can get.
If...

Adding two mm around a 44x33mm is not a big difference. There are too many variables, including the photographer standing at the same distance because the difference in the crop is not that much. Or perhaps I want the tightest crop and work at the minimum focus distance and then we are back to the smaller sensor being "better." Or perhaps I follow your strict why of photographing and I want more DoF then the smaller is better too. Or the image is being seen in a magazine at a 1/4 page or on the web, or a host of other viewing conditions you have no control over. Of course, it would be nice to actually show if there is significant different between a 44x33 and 48x36 sensor--you want to post examples?
 

Shashin

Well-known member
Again dunno why it's even an argument since most here have PLENTY of experience with this.
Like me. And there is not a significant difference between 44x33 and 48x36 sensors. There are more important specs to think about.
 

timn420

New member
I've been doing some more thinking about this and as much as I would love to just get a Pentax 645z, I don't see how 44x33mm would be much bigger or enough of a difference from full-frame 35mm. I guess with MF digital I'm looking for better subject isolation and falloff, like what I got with my 6x6 TLR, back in the day. Basically, that "pop" you see surrounding the subject with the OOF background when I shoot at 2.8

I've up'd my consideration to a "full frame" MF sensor like the P65 (54x40mm). Maybe I'm completely wrong, which is why I'm here in the forums :) but wouldn't this be the direction needed to get that "look" with portraits?
 

kdphotography

Well-known member
I've been doing some more thinking about this....

I guess with MF digital I'm looking for better subject isolation and falloff, ...

I've up'd my consideration to a "full frame" MF sensor like the P65 (54x40mm). Maybe I'm completely wrong, which is why I'm here in the forums :) but wouldn't this be the direction needed to get that "look" with portraits?
Yes. The P65+ is a great back. Now about that user interface. Have you seen the IQ160? Same sensor as the P65+ but....

Welcome to Dante's inferno.... :D

ken

p.s. Peter has one ready-to-go here: http://www.getdpi.com/forum/gear-fs...iq160-mint-still-4-yr-value-add-warranty.html
 
I've been doing some more thinking about this and as much as I would love to just get a Pentax 645z, I don't see how 44x33mm would be much bigger or enough of a difference from full-frame 35mm. I guess with MF digital I'm looking for better subject isolation and falloff, like what I got with my 6x6 TLR, back in the day. Basically, that "pop" you see surrounding the subject with the OOF background when I shoot at 2.8

I've up'd my consideration to a "full frame" MF sensor like the P65 (54x40mm). Maybe I'm completely wrong, which is why I'm here in the forums :) but wouldn't this be the direction needed to get that "look" with portraits?
I don't really associate medium format with sharp focus fall-off, a 35mm system with a fast lens is going to produce a razor thin DoF and everything immediately behind/infront is going to explode into bokeh, while a similar setup (in terms of FoV) even with a 33x44 sensor is going to be more gradual. The larger the format, the smoother the focus transition.
 

Uaiomex

Member
Regarding defocused backgrounds achieved with very fast glass in dslr's often is called by some people "smooth"or "nice bokeh" among other adjectives.
But too often I found this uber defocused backgrounds distracting to the main subject and confusing the whole speech of the work.
Medium format wins here too.

Eduardo

I don't really associate medium format with sharp focus fall-off, a 35mm system with a fast lens is going to produce a razor thin DoF and everything immediately behind/infront is going to explode into bokeh, while a similar setup (in terms of FoV) even with a 33x44 sensor is going to be more gradual. The larger the format, the smoother the focus transition.
 

GrahamWelland

Subscriber & Workshop Member
As Ken mentioned, the UI of the newer backs is a significant improvement over the P65+ and other older tech MFDBs. The difference in terms of usability and performance is ssignificant. The difference in terms of the images though is nothing. The sensor and processing is the same. The UI for using the backs though is definitely different.
 
Top