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Archive 2016Hi : ) !!! - Are Distagons soft in the corners? Biogon + Vario-Sonnar qu...
p.1 #1Hi : ) !!! - Are Distagons soft in the corners? Biogon + Vario-Sonnar question!
Hi,
There are three distagons that I have felt attracted to.
They are the (Contax) Zeiss 25, 28, and 35 mm. f/2.8
One reads good things about them, but I haven't
found much information about corner (to corner) sharp-
ness at lower aperture values; in comparison, the
Biogons with the same focal lengths are supposed
to excel. The Biogons are lighter and much more
expensive, even in the used market!
Thank you in advance, kind regards,
igmolinav : ) !!!
Mar 08, 2016 at 07:50 AM
p.1 #2Hi : ) !!! - Are Distagons soft in the corners? Biogon + Vario-Sonnar question!
None of these are sharp in the corners. They were designed for film, with which corners are less important, and the sensor covers don't help to improve things. Biogons are sharper but only on sensors with very thin cover glass.
Mar 08, 2016 at 08:06 AM
p.1 #3Hi : ) !!! - Are Distagons soft in the corners? Biogon + Vario-Sonnar question!
MTFs without sensor cover glass can be found from PDFs - on extreme corner these really were not super sharp, and even less so with digital cameras:
2.8/25
2.8/28
2.8/35
Even these lenses are SLR-lenses the sensor cover glass thickness is an issue. I never noticed any issues with Canon 1Ds, 5D, 5DmkII fullframe cameras, but Sony A7 and A7r with their super thick sensor cover glass do not work with these lenses as well as Canons did. With Sonys there is astigmatism (easily visibles with bothers me when viewing photos) on corners when shooting with 25mm and 28mm. I don't think I never had (I may had...can't remember all...) 35mm, which I used with Canon-cameras - so I cannot compare corners of 35mm.
Unless you get Kolari thin filter I would advice to forget Biogons. I currently have ZM series 2/35 and G series 2.8/28 and neither can be used with Sony 2mm thick sensor cover glass; field curvature, astigmatism issues and boke doesn't work.
I expect all mentioned lenses to work brilliantly on my A7 cameras upgraded to Kolari thin filter. I can't wait to get my camera's back, and get back the good rendering 25mm and 28mm did with Canon cameras, and to see what Biogon 2/35 ZM and Distagon 2.8/35 are really capable of.
Samuli
2.8/25
2.8/28
2.8/35
Even these lenses are SLR-lenses the sensor cover glass thickness is an issue. I never noticed any issues with Canon 1Ds, 5D, 5DmkII fullframe cameras, but Sony A7 and A7r with their super thick sensor cover glass do not work with these lenses as well as Canons did. With Sonys there is astigmatism (easily visibles with bothers me when viewing photos) on corners when shooting with 25mm and 28mm. I don't think I never had (I may had...can't remember all...) 35mm, which I used with Canon-cameras - so I cannot compare corners of 35mm.
Unless you get Kolari thin filter I would advice to forget Biogons. I currently have ZM series 2/35 and G series 2.8/28 and neither can be used with Sony 2mm thick sensor cover glass; field curvature, astigmatism issues and boke doesn't work.
I expect all mentioned lenses to work brilliantly on my A7 cameras upgraded to Kolari thin filter. I can't wait to get my camera's back, and get back the good rendering 25mm and 28mm did with Canon cameras, and to see what Biogon 2/35 ZM and Distagon 2.8/35 are really capable of.
Samuli
Mar 08, 2016 at 09:37 AM
p.1 #4Hi : ) !!! - Are Distagons soft in the corners? Biogon + Vario-Sonnar question!
A distagon design is a reversed telephoto with corrective lens(es) in place. Corners will never be stellar. Other designs emphasize corners.
Mar 08, 2016 at 09:45 AM
p.1 #5Hi : ) !!! - Are Distagons soft in the corners? Biogon + Vario-Sonnar question!
TheEmrys wrote:
A distagon design is a reversed telephoto with corrective lens(es) in place. Corners will never be stellar. Other designs emphasize corners.
That's often the case, but it can't be said of all Distagon lenses. The 28mm and 55mm Otii are both Distagons and both have excellent corners. I haven't read enough about the 28mm to know, but the Otus 55mm has good corners wide open at f/1.4.
A distagon design is a reversed telephoto with corrective lens(es) in place. Corners will never be stellar. Other designs emphasize corners.
That's often the case, but it can't be said of all Distagon lenses. The 28mm and 55mm Otii are both Distagons and both have excellent corners. I haven't read enough about the 28mm to know, but the Otus 55mm has good corners wide open at f/1.4.
Mar 08, 2016 at 11:10 AM
p.1 #6Hi : ) !!! - Are Distagons soft in the corners? Biogon + Vario-Sonnar question!
Hi,
Thank you for your messages : ) !!!
After the Kolari conversion can one use lenses from
the Sony line without any problem?? Lenses like
the zooms and primes that come with autofocus.
I was also attracted to other lenses with different
design like the
Contax Zeiss Tessar 45 mm. f/2.8, and the
Contax Zeiss Vario-Sonnar 28-85 mm. f/3.3-4.0
Will they work out ok with the camera without
the Kolari conversion?
I have in Leica mount a Canon 35 and 50 mm.,
I also have in the same mount a Leitz 50 and 90 mm.
To use them, is the Kolari conversion needed as well??
Thank you, kind regards,
igmolinav : ) !!!
Thank you for your messages : ) !!!
After the Kolari conversion can one use lenses from
the Sony line without any problem?? Lenses like
the zooms and primes that come with autofocus.
I was also attracted to other lenses with different
design like the
Contax Zeiss Tessar 45 mm. f/2.8, and the
Contax Zeiss Vario-Sonnar 28-85 mm. f/3.3-4.0
Will they work out ok with the camera without
the Kolari conversion?
I have in Leica mount a Canon 35 and 50 mm.,
I also have in the same mount a Leitz 50 and 90 mm.
To use them, is the Kolari conversion needed as well??
Thank you, kind regards,
igmolinav : ) !!!
Mar 08, 2016 at 11:22 AM
p.1 #7Hi : ) !!! - Are Distagons soft in the corners? Biogon + Vario-Sonnar question!
Very true. But it is easy enough to see the OTUS as a family of over-built lenses. I suspect they are so large because they are only using the center of the image circle. That immense sharpness of typical distagon cennters enlarged to the point where only the center of the lens image circle is used.
arduluth wrote:
That's often the case, but it can't be said of all Distagon lenses. The 28mm and 55mm Otii are both Distagons and both have excellent corners. I haven't read enough about the 28mm to know, but the Otus 55mm has good corners wide open at f/1.4.
arduluth wrote:
TheEmrys wrote
A distagon design is a reversed telephoto with corrective lens(es) in place. Corners will never be stellar. Other designs emphasize corners.Mar 08, 2016 at 01:01 PM
p.1 #8Hi : ) !!! - Are Distagons soft in the corners? Biogon + Vario-Sonnar question!
igmolinav wrote:
I was also attracted to other lenses with different
design like the
Contax Zeiss Tessar 45 mm. f/2.8, and the
Contax Zeiss Vario-Sonnar 28-85 mm. f/3.3-4.0
Will they work out ok with the camera without
the Kolari conversion?
In general, SLR lenses should be fine. I haven't seen any good evidence for claims that the Sony cover glass is a problem for SLR lenses.
igmolinav wrote:
I have in Leica mount a Canon 35 and 50 mm.,
I also have in the same mount a Leitz 50 and 90 mm.
To use them, is the Kolari conversion needed as well??
In general, most rangefinder lenses at 50mm and above perform pretty well on an unmodded A7. Most of the older lenses wider than 50mm have one or more issues - edge/corner smearing, astigmatism, field curvature, and/or color casts towards the edges of the frame. For those lenses, you'd really want to have an A7 with the Kolari conversion. At 75mm and above, I don't think I've heard of any lenses that are problematic on an unmodded A7.
For a specific lens, search the forums with Google - there's a decent chance someone has tested it already.
Edited on Mar 08, 2016 at 04:13 PM · View previous versions
I was also attracted to other lenses with different
design like the
Contax Zeiss Tessar 45 mm. f/2.8, and the
Contax Zeiss Vario-Sonnar 28-85 mm. f/3.3-4.0
Will they work out ok with the camera without
the Kolari conversion?
In general, SLR lenses should be fine. I haven't seen any good evidence for claims that the Sony cover glass is a problem for SLR lenses.
igmolinav wrote:
I have in Leica mount a Canon 35 and 50 mm.,
I also have in the same mount a Leitz 50 and 90 mm.
To use them, is the Kolari conversion needed as well??
In general, most rangefinder lenses at 50mm and above perform pretty well on an unmodded A7. Most of the older lenses wider than 50mm have one or more issues - edge/corner smearing, astigmatism, field curvature, and/or color casts towards the edges of the frame. For those lenses, you'd really want to have an A7 with the Kolari conversion. At 75mm and above, I don't think I've heard of any lenses that are problematic on an unmodded A7.
For a specific lens, search the forums with Google - there's a decent chance someone has tested it already.
Edited on Mar 08, 2016 at 04:13 PM · View previous versions
Mar 08, 2016 at 01:11 PM
p.1 #9Hi : ) !!! - Are Distagons soft in the corners? Biogon + Vario-Sonnar question!
arduluth wrote:
design like the
Contax Zeiss Tessar 45 mm. f/2.8, and the
Contax Zeiss Vario-Sonnar 28-85 mm. f/3.3-4.0
Will they work out ok with the camera without
the Kolari conversion?In general, SLR lenses should be fine. I haven't seen any good evidence for claims that the Sony cover glass is a problem for SLR lenses.
Depends very much on requirement level. As an example many claim that Zeiss ZM 1.4/35 works well with non-modified A7 cameras, while it clearly has corner smearing and color shifts and for majority it will not be usable. Some even less demanding people claim that Zeiss ZM 2/35 is fully usable with non-modified A7 cameras, which as even worse smearing and color shifts.
I compare my own results to what I got with Canon 5DmkII with same lenses. Many SLR lenses are clearly worse in Sony (e.g. C&Y mount 2.8/28). Most of my current lenses I never did shoot with Film, so I cannot compare to that (during film era I was Pentax user).
For some reason also longer SLR lenses have issues, e.g. ZE/ZF series planar 1.4/50 has been reported by some users to have gigantic field curvature with A7-series, e.g. Jochen. With this lens I have mostly suffered from worse boke quality (astigmatism in boke) compared to 5DmkII and lacking the really good performance @ f/2.8 what I experienced with 5DmkII - also short edges of image seem to suffer @ infinity due to field curvature/astigmatism compared to Canon less thick cover glass cameras (link).
From these two mentioned lens:
arduluth wrote:
I also have in the same mount a Leitz 50 and 90 mm.
To use them, is the Kolari conversion needed as well??In general, most lenses at rangefinder lenses at 50mm and above perform pretty well on an unmodded A7. Most of the older lenses wider than 50mm have one or more issues - edge/corner smearing, astigmatism, field curvature, and/or color casts towards the edges of the frame. For those lenses, you'd really want to have an A7 with the Kolari conversion. At 75mm and above, I don't think I've heard of any lenses that are problematic on an unmodded A7.
Zeiss ZM 1.5/50 definitely improves with thin sensor cover glass (it has really high ray angle for 50mm), as well as Summilux 50 & non-APO Summicron. APO-Summicron 50 & 75 have also been mentioned to improve. Contax G90 clearly improves with thin sensor cover glass. Summicron 90 boke has been mentioned to improve with Kolari mod. If you shoot close-ups, then thick sensor glass has less negative effect - it's worst @ infinity.
So again it all depends what You require from your equipment. If you don't have high requirement level then these lenses should be OK (Canon 35&50, Leica 50&90), but the 35mm may cause issues even then.
Few key threads to start getting base understanding of the topic:
Kolari Mod's Improvements: A Summary of Tests
A7/A7r - performance with WA RF lenses
Sony A7RII with leica standard M lenses?
Sony a7S infinity test w/21 rangefinder lenses (Leica, Zeiss, Voigtlander, Canon)
Latest feedback on M lenses for Sony A7/A7r
A7x.mod with SLR lenses
A thinner sensor stack may be possible after all! (jump over first 20 pages when people started getting first modified cameras)
You don't need to read these for long to understand that one man's "really good" is for other "barely usable" - some of us are more critical towards different aspects of image quality.
Also depending what you shoot - ask yourself; are the last pixels of corner of image THE most important in the world? Generally if they are, I would advice to work with the compositions you are using
Samuli
igmolinav wrote
I was also attracted to other lenses with differentdesign like the
Contax Zeiss Tessar 45 mm. f/2.8, and the
Contax Zeiss Vario-Sonnar 28-85 mm. f/3.3-4.0
Will they work out ok with the camera without
the Kolari conversion?
Depends very much on requirement level. As an example many claim that Zeiss ZM 1.4/35 works well with non-modified A7 cameras, while it clearly has corner smearing and color shifts and for majority it will not be usable. Some even less demanding people claim that Zeiss ZM 2/35 is fully usable with non-modified A7 cameras, which as even worse smearing and color shifts.
I compare my own results to what I got with Canon 5DmkII with same lenses. Many SLR lenses are clearly worse in Sony (e.g. C&Y mount 2.8/28). Most of my current lenses I never did shoot with Film, so I cannot compare to that (during film era I was Pentax user).
For some reason also longer SLR lenses have issues, e.g. ZE/ZF series planar 1.4/50 has been reported by some users to have gigantic field curvature with A7-series, e.g. Jochen. With this lens I have mostly suffered from worse boke quality (astigmatism in boke) compared to 5DmkII and lacking the really good performance @ f/2.8 what I experienced with 5DmkII - also short edges of image seem to suffer @ infinity due to field curvature/astigmatism compared to Canon less thick cover glass cameras (link).
From these two mentioned lens:
- 28-85mm should work pretty well; the ray angle is so small that field curvature and astigmatism should not cause any issue.
- I have used G45 few years on standard A7 and A7r cameras. I have not had significant issues. However extreme corners seem to have small issues, but I have nothing to compare against, might be natural performance of lens as well. I have not detected boke issues, I enjoy boke even with thick cover glass cameras very much. If this one gets better with Kolari mod, this lens will be my favorite lens, as I have liked it already very much with thick cover glass.
arduluth wrote:
igmolinav wrote
I have in Leica mount a Canon 35 and 50 mm.,I also have in the same mount a Leitz 50 and 90 mm.
To use them, is the Kolari conversion needed as well??
Zeiss ZM 1.5/50 definitely improves with thin sensor cover glass (it has really high ray angle for 50mm), as well as Summilux 50 & non-APO Summicron. APO-Summicron 50 & 75 have also been mentioned to improve. Contax G90 clearly improves with thin sensor cover glass. Summicron 90 boke has been mentioned to improve with Kolari mod. If you shoot close-ups, then thick sensor glass has less negative effect - it's worst @ infinity.
So again it all depends what You require from your equipment. If you don't have high requirement level then these lenses should be OK (Canon 35&50, Leica 50&90), but the 35mm may cause issues even then.
Few key threads to start getting base understanding of the topic:
Kolari Mod's Improvements: A Summary of Tests
A7/A7r - performance with WA RF lenses
Sony A7RII with leica standard M lenses?
Sony a7S infinity test w/21 rangefinder lenses (Leica, Zeiss, Voigtlander, Canon)
Latest feedback on M lenses for Sony A7/A7r
A7x.mod with SLR lenses
A thinner sensor stack may be possible after all! (jump over first 20 pages when people started getting first modified cameras)
You don't need to read these for long to understand that one man's "really good" is for other "barely usable" - some of us are more critical towards different aspects of image quality.
Also depending what you shoot - ask yourself; are the last pixels of corner of image THE most important in the world? Generally if they are, I would advice to work with the compositions you are using
Samuli
Mar 08, 2016 at 03:07 PM
p.1 #10Hi : ) !!! - Are Distagons soft in the corners? Biogon + Vario-Sonnar question!
Samuli Vahonen wrote:
design like the
Contax Zeiss Tessar 45 mm. f/2.8, and the
Contax Zeiss Vario-Sonnar 28-85 mm. f/3.3-4.0
Will they work out ok with the camera without
the Kolari conversion?In general, SLR lenses should be fine. I haven't seen any good evidence for claims that the Sony cover glass is a problem for SLR lenses.Depends very much on requirement level. As an example many claim that Zeiss ZM 1.4/35 works well with non-modified A7 cameras, while it clearly has corner smearing and color shifts and for majority it will not be usable. Some even less demanding people claim that Zeiss ZM 2/35 is fully usable with non-modified A7 cameras, which as even worse smearing and color shifts.
I compare my own results to what I got with Canon 5DmkII with same lenses. Many SLR lenses are clearly worse in Sony (e.g. C&Y mount 2.8/28). Most of my current lenses I never did shoot with...Show more →
I also have in the same mount a Leitz 50 and 90 mm.
To use them, is the Kolari conversion needed as well??In general, most lenses at rangefinder lenses at 50mm and above perform pretty well on an unmodded A7. Most of the older lenses wider than 50mm have one or more issues - edge/corner smearing, astigmatism, field curvature, and/or color casts towards the edges of the frame. For those lenses, you'd really want to have an A7 with the Kolari conversion. At 75mm and above, I don't think I've heard of any lenses that are problematic on an unmodded A7.
Hmm have you ever directly compared the D28 on the 5dII and a7? I would like to see that comparison a lot. Or a comparison with your a7m when it arrives.
I am a bit surprised that you do not have any issues with the G45 because that has quite excessive field curvature on the a7, here is an example.
Zeiss Planar 2/45 | f/2.8 by Phillip Reeve Data, on Flickr
Personally I haven't see a compelling comparison which showed a significantly better performance of an SLR lens on the Kolari modded a7. I have seen small improvements but I think the removed AA filter was responsible for those.
arduluth wrote
igmolinav wrote
I was also attracted to other lenses with differentdesign like the
Contax Zeiss Tessar 45 mm. f/2.8, and the
Contax Zeiss Vario-Sonnar 28-85 mm. f/3.3-4.0
Will they work out ok with the camera without
the Kolari conversion?
I compare my own results to what I got with Canon 5DmkII with same lenses. Many SLR lenses are clearly worse in Sony (e.g. C&Y mount 2.8/28). Most of my current lenses I never did shoot with...Show more →
arduluth wrote
igmolinav wrote
I have in Leica mount a Canon 35 and 50 mm.,I also have in the same mount a Leitz 50 and 90 mm.
To use them, is the Kolari conversion needed as well??
Hmm have you ever directly compared the D28 on the 5dII and a7? I would like to see that comparison a lot. Or a comparison with your a7m when it arrives.
I am a bit surprised that you do not have any issues with the G45 because that has quite excessive field curvature on the a7, here is an example.
Zeiss Planar 2/45 | f/2.8 by Phillip Reeve Data, on Flickr
Personally I haven't see a compelling comparison which showed a significantly better performance of an SLR lens on the Kolari modded a7. I have seen small improvements but I think the removed AA filter was responsible for those.
Mar 08, 2016 at 03:25 PM
p.1 #11Hi : ) !!! - Are Distagons soft in the corners? Biogon + Vario-Sonnar question!
It depends on the particular lens design of the Distagon. Some of them have softer corners due to aberrations like coma, and other aberrations, particularly older designs. Others have a lot of field curvature like the 25mm/2 ZF.2/ZE and 28mm/2 ZF/ZE, which means the lenses may appear to have soft corners at wide apertures if the subject is flat or all at infinity. Coma is pretty high on the 25mm/2 until about f/4. It's not the best 24-25mm choice for Astrophotography for example, but it's a great near-far landscape lens, because its field curvature effectively sharpens foreground detail at the expense of sky detail (which is usually an acceptable compromise).
One Zeiss Distagon that does have excellent corners is the 35mm/1.4 Distagon ZM for Leica M mount cameras. It also has very low coma, low aberrations overall, and very little field curvature. It's one of the newest Distagon designs, and includes aspheric elements and lots of special anomalous partial dispersion glass to improve resolution over previous 35mm/1.4 designs, and superficially its design appears to incorporate some characteristics of the Leica 35mm/1.4 Summilux ASPH designs with its concave front element.
One Zeiss Distagon that does have excellent corners is the 35mm/1.4 Distagon ZM for Leica M mount cameras. It also has very low coma, low aberrations overall, and very little field curvature. It's one of the newest Distagon designs, and includes aspheric elements and lots of special anomalous partial dispersion glass to improve resolution over previous 35mm/1.4 designs, and superficially its design appears to incorporate some characteristics of the Leica 35mm/1.4 Summilux ASPH designs with its concave front element.
Mar 08, 2016 at 03:43 PM
p.1 #12Hi : ) !!! - Are Distagons soft in the corners? Biogon + Vario-Sonnar question!
arduluth wrote:
I also have in the same mount a Leitz 50 and 90 mm.
To use them, is the Kolari conversion needed as well??In general, most lenses at rangefinder lenses at 50mm and above perform pretty well on an unmodded A7. Most of the older lenses wider than 50mm have one or more issues - edge/corner smearing, astigmatism, field curvature, and/or color casts towards the edges of the frame. For those lenses, you'd really want to have an A7 with the Kolari conversion. At 75mm and above, I don't think I've heard of any lenses that are problematic on an unmodded A7.
Zeiss ZM 1.5/50 definitely improves with thin sensor cover glass (it has really high ray angle for 50mm), as well as Summilux 50 & non-APO Summicron. APO-Summicron 50 & 75 have also been mentioned to improve. Contax G90 clearly improves with thin sensor cover glass. Summicron 90 boke has been mentioned to improve with Kolari mod. If you shoot close-ups, then thick sensor glass has less negative effect - it's worst @ infinity.
Like I said, "in general" and "most."
The difference in the G90 pre and post mod seems pretty minor. Maybe it's just me, but the differences in color make it hard to discern how much actual difference there actually is... when the difference is that minor, I'm not worried. Which reinforces your point about how these things are relative, very much dependent on the needs of the photographer and the scene.
I totally forgot about the ZM 50/1.5 Sonnar, but was thinking of a few Leica lenses when I said "most." They're the big exceptions when I think of 50mm RF lenses that don't do well on a stock A7.
My Canon LTM 50mm f/1.4 never get great corners at any aperture compared to my Canon FD 50mm f/1.4 SSC. I'm not sure if that's the age of the design, a design compromise (tiny lens!), or a side effect of the A7 cover glass. Possible a mix of all of the above. It's not really an issue for me, as it's definitely not a landscape lens for me.
igmolinav wrote
I have in Leica mount a Canon 35 and 50 mm.,I also have in the same mount a Leitz 50 and 90 mm.
To use them, is the Kolari conversion needed as well??
Zeiss ZM 1.5/50 definitely improves with thin sensor cover glass (it has really high ray angle for 50mm), as well as Summilux 50 & non-APO Summicron. APO-Summicron 50 & 75 have also been mentioned to improve. Contax G90 clearly improves with thin sensor cover glass. Summicron 90 boke has been mentioned to improve with Kolari mod. If you shoot close-ups, then thick sensor glass has less negative effect - it's worst @ infinity.
Like I said, "in general" and "most."
The difference in the G90 pre and post mod seems pretty minor. Maybe it's just me, but the differences in color make it hard to discern how much actual difference there actually is... when the difference is that minor, I'm not worried. Which reinforces your point about how these things are relative, very much dependent on the needs of the photographer and the scene.
I totally forgot about the ZM 50/1.5 Sonnar, but was thinking of a few Leica lenses when I said "most." They're the big exceptions when I think of 50mm RF lenses that don't do well on a stock A7.
My Canon LTM 50mm f/1.4 never get great corners at any aperture compared to my Canon FD 50mm f/1.4 SSC. I'm not sure if that's the age of the design, a design compromise (tiny lens!), or a side effect of the A7 cover glass. Possible a mix of all of the above. It's not really an issue for me, as it's definitely not a landscape lens for me.
Mar 08, 2016 at 04:13 PM
p.1 #13Hi : ) !!! - Are Distagons soft in the corners? Biogon + Vario-Sonnar question!
Phillip Reeve wrote:
I am a bit surprised that you do not have any issues with the G45 because that has quite excessive field curvature on the a7, here is an example.
https://farm2.staticflickr.com/1624/25327844790_c2907e471d_h.jpg
Zeiss Planar 2/45 | f/2.8 by Phillip Reeve Data, on Flickr
There is some field curvature, but at least for me it's never had any significant impact on my photos. Most of it seems to be in the last few 5-10mm of the image circle, and that's at f/2.8-4. Even less noticeable at f/8. Mind you, this is based on my experience using this lens for many thousands of frames, I've never done any kind of proper test. The field curvature of the G 28mm f/2.8 Biogon is another story.
Phillip Reeve wrote:
Personally I haven't see a compelling comparison which showed a significantly better performance of an SLR lens on the Kolari modded a7. I have seen small improvements but I think the removed AA filter was responsible for those.
Same here. I'd be curious to see some examples where it's significant.
I am a bit surprised that you do not have any issues with the G45 because that has quite excessive field curvature on the a7, here is an example.
https://farm2.staticflickr.com/1624/25327844790_c2907e471d_h.jpg
Zeiss Planar 2/45 | f/2.8 by Phillip Reeve Data, on Flickr
There is some field curvature, but at least for me it's never had any significant impact on my photos. Most of it seems to be in the last few 5-10mm of the image circle, and that's at f/2.8-4. Even less noticeable at f/8. Mind you, this is based on my experience using this lens for many thousands of frames, I've never done any kind of proper test. The field curvature of the G 28mm f/2.8 Biogon is another story.
Phillip Reeve wrote:
Personally I haven't see a compelling comparison which showed a significantly better performance of an SLR lens on the Kolari modded a7. I have seen small improvements but I think the removed AA filter was responsible for those.
Same here. I'd be curious to see some examples where it's significant.
Mar 08, 2016 at 04:21 PM
p.1 #14Hi : ) !!! - Are Distagons soft in the corners? Biogon + Vario-Sonnar question!
igmolinav wrote:
Contax Zeiss Tessar 45 mm. f/2.8, and the
I found the Pancake Tessar to have slightly purplish corners at infinity on both my 5D II (used with live view as it hits the mirror otherwise) and my A7 (without filter mod) when used wide open. Not too a degree that ever bothered me though, and this probably can be fixed in post. These days I don't use it much anymore as I acquired a Contax G45 f2.
Contax Zeiss Tessar 45 mm. f/2.8, and the
I found the Pancake Tessar to have slightly purplish corners at infinity on both my 5D II (used with live view as it hits the mirror otherwise) and my A7 (without filter mod) when used wide open. Not too a degree that ever bothered me though, and this probably can be fixed in post. These days I don't use it much anymore as I acquired a Contax G45 f2.
Mar 08, 2016 at 04:38 PM
p.1 #15Hi : ) !!! - Are Distagons soft in the corners? Biogon + Vario-Sonnar question!
Phillip Reeve wrote:
Hmm have you ever directly compared the D28 on the 5dII and a7? I would like to see that comparison a lot. Or a comparison with your a7m when it arrives.
I am a bit surprised that you do not have any issues with the G45 because that has quite excessive field curvature on the a7, here is an example.
https://farm2.staticflickr.com/1624/25327844790_c2907e471d_h.jpg
Zeiss Planar 2/45 | f/2.8 by Phillip Reeve Data, on Flickr
Personally I haven't see a compelling comparison which showed a significantly better performance of an SLR lens on the Kolari modded a7. I have seen small improvements but I think the...Show more →
I have not done direct comparison between 5DmkII and A7, and will not do - unless I want to kill my interest to photography, then maybe I do this...I find nothing more boring than shooting same scenes, which are usually artistically crappy, with multiple lenses/equipment. My process is different; I'm not here to compare lenses, I'm here to know the equipment best suiting for my use and to get best out from the equipment when I shoot my subjects. When I have new lens I shoot in beginning extensively aperture series from every scene/subject and back home study the results until I understand how the lens renders in various situations I will be using it coming decades.
Example how thick sensor glass ruins Carl Zeiss Distagon T* 2.8/28 - the extreme corners are just weird in A7 - they never were like this in 5DmkII:
Look how unnatural lens becomes in A7 - two major differences to 5DmkII in this sample:
So even SLR-lens I don't consider this lens to be usable with standard A7 cameras, except for close-ups which hide these issues - most likely f/8-11 landscape shooting hides issues as well. Other similar example. Otherwise I just love how this lens renders, even in A7(r) - example where I almost was able to hide (top left corner & left edge ruins it) the thick sensor glass issues using lake and sky: example - just loving it's rendering style, can't wait to shoot with 0.8mm sensor cover glass without outward field curvature and astigmatism.
G45 - I only shoot this far f/8 or f/11 landscapes. Not many of those either, this lens never left Finland with me = used mostly my normal boke shooting, not so many landscapes. The field curvature has not been issue on real shooting I do with the lens. For infinity landscape shooting bigger problem for me have been mushy extreme corners @f/5.6 when the overall rendering is best - the corners get OK f8-11 but overall rendering gets worse. In practice even at 4-5m distance photos, I have not experienced field curvature issues in my forest scenes. Tens of other lenses have had field curvature caused boke issues on my usual shooting scenarios, making them less usable with A7(r).
Like said - it depends on photographers requirements, wide aperture infinity shooting is on very bottom on my requirement list - I do not have any practical application for that. When I'm in Finland, I almost never shoot landscapes - if I do due then it's usually cropped to 16:9 or 2.35:1 due to flat land here, we have no mountains. My problems are usually on boke or curvature of DOF (or variations of DOF thickness) - the astigmatism on nature backgrounds (think about forest undergrowth, twigs and bushes) ruins many lenses. Also I don't pixel peep - more or less I'm happy if images come out pixel level sharp when displayed on 65" 4K screen watching from ~1.5m distance (or equivalent print). So small pixel level things like removing the weak AA-filter from A7 are not meaningful. If you need to find info about pixel peeping stuff @ infinity, please don't ask me, I could not care less - I do understand that this stuff is important for you for example as you write reviews and this kind of stuff most likely interest your readers. Few of the threads linked have specialized to this infinity stuff.
Also, I don't see field curvature always negative thing - the natural field curvature of Zeiss 1.4/50 planar is beneficial on majority of my scenes. Basically when field curves on corners towards camera, it nicely compensates thicker DOF in corners in most of practical scenarios (if you include foreground boke, then it works against you). However the thick sensor cover glass causes the curvature of field to be opposite; corners focus to larger distances - this can't never look good. Also lenses with mid-dip I can't see anything positive on field curvature. And of infinity landscapes it naturally would be best to have flat field and no curvature at all.
arduluth wrote:
Like I said, "in general" and "most."
Yes, most are OKish.
arduluth wrote:
My Canon LTM 50mm f/1.4 never get great corners at any aperture compared to my Canon FD 50mm f/1.4 SSC. I'm not sure if that's the age of the design, a design compromise (tiny lens!), or a side effect of the A7 cover glass. Possible a mix of all of the above. It's not really an issue for me, as it's definitely not a landscape lens for me.
It might be that it's not very good even 0mm sensor cover glass (=with film) what comes to sharpness in corners, it's pretty old design. I would be more interested how is the corner boke; are there astigmatism issues due to sensor glass like in other 1.4/50 rangefinder lenses & A7? I have always room for one more 50mm lens specially if I like it's boke and DOF transitions.
igmolinav, apologies - I missread your question: you asked about Tessar 45 - I know nothing about that lens, I accidentally read Planar 45 = G45. Never used Tessar pancake lens on any camera, also not many photos shown in here on past 13 years I have been reading this forum.
Samuli
Hmm have you ever directly compared the D28 on the 5dII and a7? I would like to see that comparison a lot. Or a comparison with your a7m when it arrives.
I am a bit surprised that you do not have any issues with the G45 because that has quite excessive field curvature on the a7, here is an example.
https://farm2.staticflickr.com/1624/25327844790_c2907e471d_h.jpg
Zeiss Planar 2/45 | f/2.8 by Phillip Reeve Data, on Flickr
Personally I haven't see a compelling comparison which showed a significantly better performance of an SLR lens on the Kolari modded a7. I have seen small improvements but I think the...Show more →
I have not done direct comparison between 5DmkII and A7, and will not do - unless I want to kill my interest to photography, then maybe I do this...I find nothing more boring than shooting same scenes, which are usually artistically crappy, with multiple lenses/equipment. My process is different; I'm not here to compare lenses, I'm here to know the equipment best suiting for my use and to get best out from the equipment when I shoot my subjects. When I have new lens I shoot in beginning extensively aperture series from every scene/subject and back home study the results until I understand how the lens renders in various situations I will be using it coming decades.
Example how thick sensor glass ruins Carl Zeiss Distagon T* 2.8/28 - the extreme corners are just weird in A7 - they never were like this in 5DmkII:
Look how unnatural lens becomes in A7 - two major differences to 5DmkII in this sample:
- the top left corner (right as well but left better example); field curvature causes the background to look like it's almost in focus @ corner - 700px towards to image center, and boke quite same as in center.
- both bottom corners - sudden change in very extend of corner (I do NOT expect 100% contrast and sharpness, but going to full blur in 50px distance just did not happen with 5DmkII)
So even SLR-lens I don't consider this lens to be usable with standard A7 cameras, except for close-ups which hide these issues - most likely f/8-11 landscape shooting hides issues as well. Other similar example. Otherwise I just love how this lens renders, even in A7(r) - example where I almost was able to hide (top left corner & left edge ruins it) the thick sensor glass issues using lake and sky: example - just loving it's rendering style, can't wait to shoot with 0.8mm sensor cover glass without outward field curvature and astigmatism.
G45 - I only shoot this far f/8 or f/11 landscapes. Not many of those either, this lens never left Finland with me = used mostly my normal boke shooting, not so many landscapes. The field curvature has not been issue on real shooting I do with the lens. For infinity landscape shooting bigger problem for me have been mushy extreme corners @f/5.6 when the overall rendering is best - the corners get OK f8-11 but overall rendering gets worse. In practice even at 4-5m distance photos, I have not experienced field curvature issues in my forest scenes. Tens of other lenses have had field curvature caused boke issues on my usual shooting scenarios, making them less usable with A7(r).
Like said - it depends on photographers requirements, wide aperture infinity shooting is on very bottom on my requirement list - I do not have any practical application for that. When I'm in Finland, I almost never shoot landscapes - if I do due then it's usually cropped to 16:9 or 2.35:1 due to flat land here, we have no mountains. My problems are usually on boke or curvature of DOF (or variations of DOF thickness) - the astigmatism on nature backgrounds (think about forest undergrowth, twigs and bushes) ruins many lenses. Also I don't pixel peep - more or less I'm happy if images come out pixel level sharp when displayed on 65" 4K screen watching from ~1.5m distance (or equivalent print). So small pixel level things like removing the weak AA-filter from A7 are not meaningful. If you need to find info about pixel peeping stuff @ infinity, please don't ask me, I could not care less - I do understand that this stuff is important for you for example as you write reviews and this kind of stuff most likely interest your readers. Few of the threads linked have specialized to this infinity stuff.
Also, I don't see field curvature always negative thing - the natural field curvature of Zeiss 1.4/50 planar is beneficial on majority of my scenes. Basically when field curves on corners towards camera, it nicely compensates thicker DOF in corners in most of practical scenarios (if you include foreground boke, then it works against you). However the thick sensor cover glass causes the curvature of field to be opposite; corners focus to larger distances - this can't never look good. Also lenses with mid-dip I can't see anything positive on field curvature. And of infinity landscapes it naturally would be best to have flat field and no curvature at all.
arduluth wrote:
Like I said, "in general" and "most."
Yes, most are OKish.
arduluth wrote:
My Canon LTM 50mm f/1.4 never get great corners at any aperture compared to my Canon FD 50mm f/1.4 SSC. I'm not sure if that's the age of the design, a design compromise (tiny lens!), or a side effect of the A7 cover glass. Possible a mix of all of the above. It's not really an issue for me, as it's definitely not a landscape lens for me.
It might be that it's not very good even 0mm sensor cover glass (=with film) what comes to sharpness in corners, it's pretty old design. I would be more interested how is the corner boke; are there astigmatism issues due to sensor glass like in other 1.4/50 rangefinder lenses & A7? I have always room for one more 50mm lens
specially if I like it's boke and DOF transitions.igmolinav, apologies - I missread your question: you asked about Tessar 45 - I know nothing about that lens, I accidentally read Planar 45 = G45. Never used Tessar pancake lens on any camera, also not many photos shown in here on past 13 years I have been reading this forum.
Samuli
Mar 08, 2016 at 04:56 PM
p.1 #16Hi : ) !!! - Are Distagons soft in the corners? Biogon + Vario-Sonnar question!
It's getting OT, and I can't speak to it since I've never used the C/Y 28/2.8 Distagon... but do you have any comparisons between A7 and Canon FF shots with it to illustrate? Just looks like crummy wide angle corners.
Samuli Vahonen wrote:
It might be that it's not very good even 0mm sensor cover glass (=with film) what comes to sharpness in corners, it's pretty old design. I would be more interested how is the corner boke; are there astigmatism issues due to sensor glass like in other 1.4/50 rangefinder lenses & A7? I have always room for one more 50mm lens specially if I like it's boke and DOF transitions.
No clue how the corner bokeh is - it's even less important to me than deep corner performance. :P I'd be happy to take an aperture series for you, though - how would one test that sort of thing?
Samuli Vahonen wrote:
It might be that it's not very good even 0mm sensor cover glass (=with film) what comes to sharpness in corners, it's pretty old design. I would be more interested how is the corner boke; are there astigmatism issues due to sensor glass like in other 1.4/50 rangefinder lenses & A7? I have always room for one more 50mm lens
specially if I like it's boke and DOF transitions.No clue how the corner bokeh is - it's even less important to me than deep corner performance. :P I'd be happy to take an aperture series for you, though - how would one test that sort of thing?
Mar 08, 2016 at 05:08 PM
p.1 #17Hi : ) !!! - Are Distagons soft in the corners? Biogon + Vario-Sonnar question!
Samuli Vahonen wrote:
MTFs without sensor cover glass can be found from PDFs - on extreme corner these really were not super sharp, and even less so with digital cameras:
2.8/25
2.8/28
2.8/35
Even these lenses are SLR-lenses the sensor cover glass thickness is an issue. I never noticed any issues with Canon 1Ds, 5D, 5DmkII fullframe cameras, but Sony A7 and A7r with their super thick sensor cover glass do not work with these lenses as well as Canons did. With Sonys there is astigmatism (easily visibles with bothers me when viewing photos) on corners when shooting with 25mm and 28mm. I don't think I...Show more →
According to Roger from LensRentals the Sony cover glass is about the same as most canon ones. It's not super thick. It's only thick in comparison with Leica (which is super thin, to minimise the problem with RF lenses)
MTFs without sensor cover glass can be found from PDFs - on extreme corner these really were not super sharp, and even less so with digital cameras:
2.8/25
2.8/28
2.8/35
Even these lenses are SLR-lenses the sensor cover glass thickness is an issue. I never noticed any issues with Canon 1Ds, 5D, 5DmkII fullframe cameras, but Sony A7 and A7r with their super thick sensor cover glass do not work with these lenses as well as Canons did. With Sonys there is astigmatism (easily visibles with bothers me when viewing photos) on corners when shooting with 25mm and 28mm. I don't think I...Show more →
According to Roger from LensRentals the Sony cover glass is about the same as most canon ones. It's not super thick. It's only thick in comparison with Leica (which is super thin, to minimise the problem with RF lenses)
Mar 08, 2016 at 05:27 PM
p.1 #18Hi : ) !!! - Are Distagons soft in the corners? Biogon + Vario-Sonnar question!
arduluth wrote:
It's getting OT, and I can't speak to it since I've never used the C/Y 28/2.8 Distagon... but do you have any comparisons between A7 and Canon FF shots with it to illustrate? Just looks like crummy wide angle corners.
It's not about "crummy" corners - when stuff, which should not be in focus is in focus, it's not just bad performance - if something is just soft then it can be "crummy wide angle corners". Bottom corners in example could be just bad performance, but they are blurry because the focus is 2 meters under ground due to field curvature. Neither of this just never happened with 5DmkII. Like said I don't do comparisons unless I want to end whole hobby for me. During the time I have owned A7 cameras the last 5DmkII was permanently attached to Zeiss APO135. It's been over year since I sold the last 5DmkII body and now I only have Sony 2xA7 & A7r and a850, no Canon bodies left.
I don't have suitable 5DmkII sample online - however this was shot with C/Y Distagon 2.8/25 wide open, and notice how there is no field curvature towards infinity in corners. If I would shoot the same shot with A7, for example mountain at image right edge 1 kilometer away would be sharp, due to outward field curvature.
This was shot with C/Y Distagon 2.8/28 @ f/11, but even this small aperture would not have been enough to overcome the field curvature of A7 thick cover glass, and it would not have been impossible to adjust focus distance so that it's sharp @ infinity AND on right edge 1 meter distance. With 5DmkII I was able to utilize the natural inward field curvature of this lens to help bottom right corner being so sharp (bottom left and top right corners would have preferred flat curvature of field).
arduluth wrote:
No clue how the corner bokeh is - it's even less important to me than deep corner performance. :P I'd be happy to take an aperture series for you, though - how would one test that sort of thing?
This is very simple; take few photos where you have tangential and sagittal detail behind the DOF in different distances quite close to focus plane. If different depths and details directions have different blur levels lens either produces naturally crappy corner boke or crappy boke is caused by astigmatism, which is caused by thick sensor cover glass. You never care about this stuff IF you shoot only in urban environment only where surfaces are planar and smooth - any lens draws good boke on this kind of boring environment.
DavidBM wrote:
According to Roger from LensRentals the Sony cover glass is about the same as most canon ones. It's not super thick. It's only thick in comparison with Leica (which is super thin, to minimise the problem with RF lenses)
In practice there are large differences - different refraction index of the glass? Also has Roger really said this clearly, I have missed that.
Kolarivision has different information - they disassemble the sensors and replace the cover glasses so I'm pretty sure they know this exactly: "A7x = 1.9mm 5d3=1.2mm D810=1.1mm thicknesses. Source is Kolari." - based on real life shooting I would vote for Kolari's truth. D800(would assume it's same as D810?) and 5DmkII (would assume it's same as 5DmkIII?) seemed to work same way with same lenses, and both better than a7-series.
Samuli
It's getting OT, and I can't speak to it since I've never used the C/Y 28/2.8 Distagon... but do you have any comparisons between A7 and Canon FF shots with it to illustrate? Just looks like crummy wide angle corners.
It's not about "crummy" corners - when stuff, which should not be in focus is in focus, it's not just bad performance - if something is just soft then it can be "crummy wide angle corners". Bottom corners in example could be just bad performance, but they are blurry because the focus is 2 meters under ground due to field curvature. Neither of this just never happened with 5DmkII. Like said I don't do comparisons unless I want to end whole hobby for me. During the time I have owned A7 cameras the last 5DmkII was permanently attached to Zeiss APO135. It's been over year since I sold the last 5DmkII body and now I only have Sony 2xA7 & A7r and a850, no Canon bodies left.
I don't have suitable 5DmkII sample online - however this was shot with C/Y Distagon 2.8/25 wide open, and notice how there is no field curvature towards infinity in corners. If I would shoot the same shot with A7, for example mountain at image right edge 1 kilometer away would be sharp, due to outward field curvature.
This was shot with C/Y Distagon 2.8/28 @ f/11, but even this small aperture would not have been enough to overcome the field curvature of A7 thick cover glass, and it would not have been impossible to adjust focus distance so that it's sharp @ infinity AND on right edge 1 meter distance. With 5DmkII I was able to utilize the natural inward field curvature of this lens to help bottom right corner being so sharp (bottom left and top right corners would have preferred flat curvature of field).
arduluth wrote:
No clue how the corner bokeh is - it's even less important to me than deep corner performance. :P I'd be happy to take an aperture series for you, though - how would one test that sort of thing?
This is very simple; take few photos where you have tangential and sagittal detail behind the DOF in different distances quite close to focus plane. If different depths and details directions have different blur levels lens either produces naturally crappy corner boke or crappy boke is caused by astigmatism, which is caused by thick sensor cover glass. You never care about this stuff IF you shoot only in urban environment only where surfaces are planar and smooth - any lens draws good boke on this kind of boring environment.
DavidBM wrote:
According to Roger from LensRentals the Sony cover glass is about the same as most canon ones. It's not super thick. It's only thick in comparison with Leica (which is super thin, to minimise the problem with RF lenses)
In practice there are large differences - different refraction index of the glass? Also has Roger really said this clearly, I have missed that.
Kolarivision has different information - they disassemble the sensors and replace the cover glasses so I'm pretty sure they know this exactly: "A7x = 1.9mm 5d3=1.2mm D810=1.1mm thicknesses. Source is Kolari." - based on real life shooting I would vote for Kolari's truth. D800(would assume it's same as D810?) and 5DmkII (would assume it's same as 5DmkIII?) seemed to work same way with same lenses, and both better than a7-series.
Samuli
Mar 08, 2016 at 06:01 PM
p.1 #19Hi : ) !!! - Are Distagons soft in the corners? Biogon + Vario-Sonnar question!
Samuli Vahonen wrote:
It's not about "crummy" corners - when stuff, which should not be in focus is in focus, it's not just bad performance - if something is just soft then it can be "crummy wide angle corners". Bottom corners in example could be just bad performance, but they are blurry because the focus is 2 meters under ground due to field curvature. Neither of this just never happened with 5DmkII. Like said I don't do comparisons unless I want to end whole hobby for me. During the time I have owned A7 cameras the last 5DmkII was permanently attached to...Show more →
Rogers article was June 2014.
The Canons vary enormously:
Original 5d between 1.5 and 2 (maybe varied across its run)
1dsii 1
30d 2.5
6d (the most recent if these) 2
The Sony A7s materially agreeing with kolari at 1.8
Leica as low as .5
I don't think there's variation between performance on Canon bodies for stack related reasons, nor is there difference for stack related reasons between canon bodies and Sony ones. Reason: the designs have sufficiently moderate ray angles that sensor stack makes no material difference.
Some M mount lenses are a perfect storm of trouble on E mount because of a combination of factors: first they are designed for film or a .5mm stack, AND they have extreme ray angles which makes this relevant. Neither factor alone will give trouble.
arduluth wrote
It's getting OT, and I can't speak to it since I've never used the C/Y 28/2.8 Distagon... but do you have any comparisons between A7 and Canon FF shots with it to illustrate? Just looks like crummy wide angle corners.arduluth wrote
No clue how the corner bokeh is - it's even less important to me than deep corner performance. :P I'd be happy to take an aperture series for you, though - how would one test that sort of thing?DavidBM wrote
According to Roger from LensRentals the Sony cover glass is about the same as most canon ones. It's not super thick. It's only thick in comparison with Leica (which is super thin, to minimise the problem with RF lenses)Rogers article was June 2014.
The Canons vary enormously:
Original 5d between 1.5 and 2 (maybe varied across its run)
1dsii 1
30d 2.5
6d (the most recent if these) 2
The Sony A7s materially agreeing with kolari at 1.8
Leica as low as .5
I don't think there's variation between performance on Canon bodies for stack related reasons, nor is there difference for stack related reasons between canon bodies and Sony ones. Reason: the designs have sufficiently moderate ray angles that sensor stack makes no material difference.
Some M mount lenses are a perfect storm of trouble on E mount because of a combination of factors: first they are designed for film or a .5mm stack, AND they have extreme ray angles which makes this relevant. Neither factor alone will give trouble.
Mar 09, 2016 at 03:24 PM
p.1 #20Hi : ) !!! - Are Distagons soft in the corners? Biogon + Vario-Sonnar question!
Hi,
Thank you very much for your responses : ) !!!
It is humbling to receive such amazing
responses !!!
Very kind regards,
igmolinav : ) !!!
Mar 14, 2016 at 05:56 PM