Tariq Gibran wrote:
Edward, I think the oof shape you note on the FE 55 is specific to that particular lens design. It bothers me as well - and is why I don't really think I will buy that lens. Other 50's don't do that universally on the A7's so I'm not so sure it's due to the sensor (or some design factor) stretching bokeh per se.
You may be right Tariq, but I can't be really sure. I remember having seen the same effect in my FE 35 photos, and even with ZM lenses, that area showed the same stretching though with much more blur due to the astigmatism.
adamdewilde wrote:
Seems odd that the aperture ring moves in the opposite direction of existing Zeiss lens rings. I call shenanigans!
The picture is "SR6" according to Andrea (which presumably means it was delivered to him by the Sony CEO, in person). So looks like the backwards aperture ring is real. I can live with that.
sebboh wrote:
the zm 35/2 isn't that bad on the a7, so I can imagine it working with some minor reformulating for the sensor stack. hopefully they did more than that, I'm really not a fan of its bokeh at portrait distance.
I found the biogon really bad on the A7. About 30% of the frame was completely unusable at infinity, even stopped down. It was amazingly sharp in the center though, and at portrait distances as well, as long as the subject was in the center area. The bokeh of this lens is actually quite good once you stop down to 2.8 but I agree that it can be really bad wide open.
edwardkaraa wrote:
You may be right Tariq, but I can't be really sure. I remember having seen the same effect in my FE 35 photos, and even with ZM lenses, that area showed the same stretching though with much more blur due to the astigmatism.
I'm not positive either. I looked at a few wide open 50 shots of mine with various lenses (R Summicron and a Pentax Super Tak) and while the center oof areas are perfectly round, the oof shapes at the corners do take on an odd shape so I'm not sure if this is just the lens abberations or some interaction with the A7r mount, etc.
sebboh wrote:
the zm 35/2 isn't that bad on the a7, so I can imagine it working with some minor reformulating for the sensor stack. hopefully they did more than that, I'm really not a fan of its bokeh at portrait distance.
Of course, it has to be better than just not that bad. Maybe they will make it even more of a Distagon (I think Zeiss use the term "Distagon genes" or something) but still call it a Biogon.
Tariq Gibran wrote:
I'm not positive either. I looked at a few wide open 50 shots of mine with various lenses (R Summicron and a Pentax Super Tak) and while the center oof areas are perfectly round, the oof shapes at the corners do take on an odd shape so I'm not sure if this is just the lens abberations or some interaction with the A7r mount, etc.
Tariq Gibran wrote:
I'm not positive either. I looked at a few wide open 50 shots of mine with various lenses (R Summicron and a Pentax Super Tak) and while the center oof areas are perfectly round, the oof shapes at the corners do take on an odd shape so I'm not sure if this is just the lens abberations or some interaction with the A7r mount, etc.
oof highlights from the rokkor seem pretty much the same shape in the corners as on film, and nothing like the FE 55.
edwardkaraa wrote:
I found the biogon really bad on the A7. About 30% of the frame was completely unusable at infinity, even stopped down. It was amazingly sharp in the center though, and at portrait distances as well, as long as the subject was in the center area. The bokeh of this lens is actually quite good once you stop down to 2.8 but I agree that it can be really bad wide open.
hmm, i thought i saw samples where it performed well across the frame by f/8-11. maybe those were focused closer and using dof to bring infinity in.
sebboh wrote:
hmm, i thought i saw samples where it performed well across the frame by f/8-11. maybe those were focused closer and using dof to bring infinity in.
I think by f/11 the results are reasonably ok, but nothing to brag about. When you see how this lens performs on a Leica M you will certainly find the results on the A7 to be unacceptable.
This is with A7 and FE 35. No bokeh but flare in the same axis. I never get this with the ZM 35 on a M body, but I was getting similar flare on the A7 as well:
That's the question I guess. Is there mechanical vignetting introduced somewhere in the light path. This is wide open so it's not the aperture shape. It's being somewhat distorted by aberrations (coma maybe) would be my guess.
edwardkaraa wrote:
This is with A7 and FE 35. No bokeh but flare in the same axis. I never get this with the ZM 35 on a M body, but I was getting similar flare on the A7 as well:
edwardkaraa wrote:
This is with A7 and FE 35. No bokeh but flare in the same axis. I never get this with the ZM 35 on a M body, but I was getting similar flare on the A7 as well:
Tariq Gibran wrote:
That's the question I guess. Is there mechanical vignetting introduced somewhere in the light path. This is wide open so it's not the aperture shape. It's being somewhat distorted by aberrations (coma maybe) would be my guess.
that looks like the lenses natural mechanical vignetting. as far as mechanical vignetting caused behind the lens, i find the a7 to be better than the 5D in this respect with my rokkor (which gets clipped highlights on the 5D but not the a7). stuff that happens in front of the lens usually makes cat's eyes while stuff in the back tends be straight edges with a hard cut off.
sebboh wrote:
that looks like the lenses natural mechanical vignetting. as far as mechanical vignetting caused behind the lens, i find the a7 to be better than the 5D in this respect with my rokkor (which gets clipped highlights on the 5D but not the a7). stuff that happens in front of the lens usually makes cat's eyes while stuff in the back tends be straight edges with a hard cut off.
Yeah, I have been doing some research on it just now and I believe you are correct.
edwardkaraa wrote:
I think by f/11 the results are reasonably ok, but nothing to brag about. When you see how this lens performs on a Leica M you will certainly find the results on the A7 to be unacceptable.
yeah, i was just saying the fact that it is usable on the a7 unlike the zm 21s suggests it will need less design modification (i would think).
on a side note, a lenses performance on other cameras has zero influence on whether i find it's performance acceptable on my camera.
that just looks like an effect of lens design to me. a lot of the faster sony zeiss lenses and even some older contax lenses have corner bokeh that can look kinda like that. it's pretty dependent on subject and background distance though.
