Biogon 25mm f2.8.... Anyone using it on Xpro1?

[semilog]

I would have thought that because the zm lenses are designed cover full format 135, by using on a smaller format sensor you will only be using the central portion of the lens and the obliqueness of lightray angles would be reduced in the corners to less than on an M9. So I'm surprised its a problem.

A lot of M-mount wide angle lenses have rear nodal points very close to the film, and small exit pupils. At the corners the light is coming in at very shallow angles of attack, even in an APS-C crop. The Zeiss PDF linked above shows MTF data for the ZM 21/2.8 in APS-C crop. It's a real problem.

 

[aleksanderpolo]

Hey Tony,

The GXR definitely quenched my desire to get the XP1 for M-lenses. The focus assist mode 2, the three different magnification (2x,4x,8x), the more responsive EVF (the one that olympus used), the microlenses optimized for wide M (the CV15 on GXR has sharp corner at f8 at 100% crop, you can check the picabroad link and see that it doesn't on XP1). Only drawback is that it has slow buffer and slow shot to shot time, and of course its high ISO is not as good as Fuji. But at base ISO it has a clarity that is stunning, due to the lack of AA filter and the use of traditional bayer layout.

The appeal of XP1 to me is primarily the native 35/1.4. Hey, perhaps you can rent them both to see it for yourselves, as you will be using primarily M-lenses? Different people have different expectation/requirement of sharpness. I don't think these kind of "it's sharp enough" "No it's not" discussion is going to settle it for you. 🙂

 

[rbelyell]

alex thanks so much. i really respect your opinion, and i am getting to a point where i am very close to agreeing that if i want to continue using RF lenses its probably, unfortunately, not going to be with the xpro. my decision now is whether i want to abandon RF lens/digi use in favor of the xpros outstanding IQ with native lenses. maybe i do need to invest some money in rentals...

i guess i could also continue to use 40mm and above RF lenses on the xpro...):
tony

 

[.... _]

If fuji are listening maybe they will do something about it on the x-pro2 2.5mm seems awful thick for a filter on a sensor. Only now they have lenses designed for it maybe not 😉

 

[semilog]

I expect that there are good technical reasons why that cover glass is so thick. I don't pretend to know what those reasons are, though.

 

[.... _]

well yes it's mostly guesswork but zeiss had problems with its sensor covers cracking. Who knows, maybe there is a little over engineering built in for ruggedness of a "Pro" rated camera.
Anyhow, interesting thread with some good examples of what the problem really is.
I came across another page showing some more examples comparing gxr to x-pro1:

http://www.mielkephoto.com/2012/04/fuji-x-pro-1-m-mount-comparison-photos/

 

[aleksanderpolo]

Thanks for finding the test. So in this test the 18/2 which is known to have very soft corner is better than 25/2.8 which is one of the best zm, well...

 

[Matus]

The linked examples suggest (to me) that one should probably look elsewhere (than X-Pro 1) for wide angle M-mount lenses. For example Ricoh GXR :angel:

 

[GaryLH]

Hey Tony,

The GXR definitely quenched my desire to get the XP1 for M-lenses. The focus assist mode 2, the three different magnification (2x,4x,8x), the more responsive EVF (the one that olympus used), the microlenses optimized for wide M (the CV15 on GXR has sharp corner at f8 at 100% crop, you can check the picabroad link and see that it doesn't on XP1). Only drawback is that it has slow buffer and slow shot to shot time, and of course its high ISO is not as good as Fuji. But at base ISO it has a clarity that is stunning, due to the lack of AA filter and the use of traditional bayer layout.

The appeal of XP1 to me is primarily the native 35/1.4. Hey, perhaps you can rent them both to see it for yourselves, as you will be using primarily M-lenses? Different people have different expectation/requirement of sharpness. I don't think these kind of "it's sharp enough" "No it's not" discussion is going to settle it for you. 🙂

I have both the Ricoh gxr and the xp1. The gxr is the camera to use for native Leica lenses. The main reason I use the xp1 w/ adapted rf lenses is really to fill in the holes in the lens lineup... When the 14mm and 56 mm native lenses come out, then the for me the gaps will be mostly filled except for a 16mm for which the 15vc is the closest.

Right now on my gxr the 35 cron v4 is just about permanently attached to it. The only thing about the gxr that bothers me is the slower flash write speed compared to the xp1.

If using only Leica rf lenses, the gxr is the way to go...

Gary

 

[rbelyell]

gary it appears, or maybe it just appears to me, that implicit in your post is the fuji at its best (with native lenses) outperforms the gxr at its best (with very good m mount lenses). is that your judgement?
tony

 

[GaryLH]

gary it appears, or maybe it just appears to me, that implicit in your post is the fuji at its best (with native lenses) outperforms the gxr at its best (with very good m mount lenses). is that your judgement?
tony

I am not sure if I would think of it that way. More like I use the camera for different purposes. I really view it more as situations where I want to use af and the xp1, u are going to get the most out of Fuji with its native lenses since they are designed to work with their sensor whereas to adapt a Leica rf lens is going to e more hit and miss with a lot depending on focal length, how close rear element is to sensor and how picky u are in respect the the results.

The gxr is really designed for rf lenses. The end result from gxr with wide angles is going to be much better than the xp1..

The main point I was really trying to get at was if u want Leica rf lenses on a digital camera and it is not a M8 or 9 and u are not really interested in AF, the gxr is really the better way to go.

The gxr has many things going for it...
- lighter more compact body
- two modes of focus peaking
- 3 levels of magnification mode for more precise focusing
- electronic shutter mode, u think a leaf shutter is quiet 😀
- micro lenses specifically designed to handle wide angle rf lenses
- inf focus is dead on without it zone or hyper focus is questionable
- no anti-aliasing filter

Hope that clarifies what I was trying to say

Gary

 

[rbelyell]

thanks a lot gary, your insight has been very very helpful.
tony

 

[.... _]

One question about this. Are we really sure the problem is due to ONLY the thickness of the filter? The camera M-Mount adapter would appear to have correction software for each lens being used on it. So can that software correction be at least partly the cause of the smearing. i.e. is it really upto the job.
I ask because it would seem likely that using a lens filter on any wide angle lens might do the same but they don't seem to. Or do they?

 

[.... _]

One question about this. Are we really sure the problem is due to ONLY the thickness of the filter? The camera M-Mount adapter would appear to have correction software for each lens being used on it. So can that software correction be at least partly the cause of the smearing. i.e. is it really upto the job.
I ask because it would seem likely that using a lens filter on any wide angle lens might do the same but they don't seem to. Or do they?

I've been thinking about this. Dangerous I know, but what happens if you put a zeiss 25/2.8 on the fuji M-mount adapter and then tell the adapter you are using a 50/2 or an 85/2. Does the smearing get worse or better?

Has anyone tried or would anyone like to try and see what happens.

My theory, and it is just a theory is that the fuji software is designed to correct any distortion in fuji lenses. But the zeiss doesn't have any so needs no correction. If the software isn't optimised properly for the zeiss 25/2.8 then maybe lying to the camera may reduce the distortion correction which could just possibly be part of the problem.

 

[aleksanderpolo]

non-native prime do not have distortion profile in their raw, so the distortion correction is not to be blamed.

The Zeiss article has a pretty clear discussion about how the cover glass right on top of the sensor is causing problem. Whether the problem is significant for individual user is a different matter, however.

 

[.... _]

non-native prime do not have distortion profile in their raw, so the distortion correction is not to be blamed.

The Zeiss article has a pretty clear discussion about how the cover glass right on top of the sensor is causing problem. Whether the problem is significant for individual user is a different matter, however.

All theories need to be tested even if only to prove they are wrong. Such a simple test to do if you have the kit at hand.
And I'm not suggesting there isn't a problem due to thickness of filter but that just maybe there is some software processing which isn't helping as it should. And what happens if you send image to jpeg and not raw.

 

[rjx]

Let's say I wanted to use a Zeiss 21mm Distagon T* ZF (Nikon) or ZE (Canon) on the X-PRO1 w/ the appropriate converter. Would those lenses work well with zero to minimal smearing? 21mm lens on the XP1 would be a 31.5 FOV.

Thanks.

 

[aleksanderpolo]

Distagon and DSLR lens in general should not have any smearing problem.

 

[Jamie Pillers]

Is this a real-world problem?

Is this a real-world problem?

Let's say I wanted to use a Zeiss 21mm Distagon T* ZF (Nikon) or ZE (Canon) on the X-PRO1 w/ the appropriate converter. Would those lenses work well with zero to minimal smearing? 21mm lens on the XP1 would be a 31.5 FOV.

Thanks.

Is this "smearing" problem, so often thrown out there these days when discussing mf lenses on mirrorless cameras, anything worth worrying about. Has anyone seen a real print from this camera/lens combination. No comment I've read on the web about this "smearing" mentions how prints on the wall look. I get a strong feeling that this "smearing problem" is just the usual junk from armchair pixel peepers. Anyone here have real world experience making big prints that look bad?

 

[rjx]

Distagon and DSLR lens in general should not have any smearing problem.

Thanks. That's what I assumed. But sometimes my assumptions are wrong. BTW, I forgot Zeiss released the Distagon T* 25mm f/2.8 for ZE and ZF. So I'd probably select that one since I was originally hoping to use the Biogon 25mm f2.8 in the first place 🙂