10-25-2010, 11:24 AM
Hi Javier,
[quote name='Light Is Beauty' timestamp='1287975147' post='3766']
Over the last few days I've been reading your responses and trying to digest all the information and data. Thank you all for an hugely informative thread! Coincidentally this post by Ben Horton ([url="http://photocinenews.com/2010/10/22/nat-geo-shooter-ben-horton-compares-canon-glass-to-zeiss-glass/"]http://photocinenews...to-zeiss-glass/[/url]) went up two days ago and has been getting a lot of attention. The testing was far from scientific and the sample Canon images are presented on a much higher contrast scene than the Zeiss, which also shows green/purple fringing from CAs on certain edges.
Out of curiosity I checked and found that Photozone had in fact reviewed that lens and had shown the Zeiss to be not quite as strong optically as the Canon 85mm f/1.2 L.
Since its my understanding that medium format digital does not have AA filters, and has to have glass that can provide that native sharpness, wouldn't a lens designed for medium format theoretically be able to provide a higher quality image? Could it be that the AA on the FF and APS-C bodies work against the higher grade glass?
-Javier
[/quote]
First of all, take Ben Horton's "review" with a pinch or salt or two. He doesn't seem to know all that much about optics. For starters, he compares pineapples and cucumbers, as primes should never be compared with zooms - zooms almost always fare a lot worse (exceptions being Canon 70-200 F/4L IS, 70-200 F/2.8L IS Mk II, Nikkor 14-24 F/2.8). IMO, it is actually amazing that the 16-35 does so well against the Zeiss 18 F/3.5, which says more about the Zeiss than about the 16-35L (and it happens to be a well known fact that the ZE 18 isn't really all that great compared to glass in the same category). I have tested a bunch of Zeiss lenses myself, excluding the 50 F/2, 35 F/2 and 25 F/2, and personally I don't like Zeiss glass - do note that this is what it is about in the end: do you like the rendering or not - cooler colours, a lot of light fall-off towards the corners, way, way more than the Canon lenses I use myself. The really good Zeiss glass are the 35 F/2, 50 F/2 and 100 F/2, especially the latter, the rest are bettered easily by good Canon glass if you ask me. But again, that is personal.
Zeiss glass is good, generally speaking, but they need to be compared to similar Canon glass, and those are equally good, some are silghtly better, and vice versa, it is that simple.
BTW, I personally happen to know a NatGeo photographer who uses Canon and Canon glass, those awful L-zooms, to great effect (and I am talking about the shorter lenses here), and I also know that several NatGeo photogrpahers uses Olympus 4/3 cameras and lenses.
Medium format lenses generally have lower resolution than 35 mm format lenses, so they would generally not provide higher image quality on dslrs. However, they are fun to play with, especially when used with TS-adapters (they have a much larger image circle after all). And no, the AA filters do not work agianst the higher grade glass, even though it seems that way. Without them, you actually get spurious resolution, details which don't exist, and moiré, which can't be cleaned up by software, whatever anybody says - after the fact this literally is impossible, because the original data (the actual light rays falling onto the sensor) are no longer available.
What a lot of people still don't understand, is that every digital image needs sharpening, and with AA-filters a little more than without one. However, when applied well you should get the same results as with out an AA-filter, minus spurious elements and moiré.
To (try and) keep a long story short: all world class glass, whether it is Nikon pro lenses, Canon pro lenses, Zeiss lenses, or Sony pro glass, is so good, you won't see a real difference in print, other than rendering characteristics. Anything else is PP skils, and for size, FF (better quality at large sizes). Lenses are better than they ever were before, and you won't be able to tell the IQ and optical differences apart when looking at any picture the size of, let's say, A4 prints, and smaller. The difference is really in the processing. I still have a few 60 cm X 90 cm and 40 cm X 60 cm prints on the wall, taken with the "lowly" 350D and 400D, with lenses like the 70-200 F/4L plus 2X extender, TS-E 24L (Mk I), and 100-400L, supposedly all not so great lenses or combinations. It is really in the end about the photographer, his or her vision, and the way that vision is worked out in the final picture. Anything that gets good or better grades here on Photozone in tests, essentially is a fabulous lens to take pictures with.
Kind regards, Wim
[quote name='Light Is Beauty' timestamp='1287975147' post='3766']
Over the last few days I've been reading your responses and trying to digest all the information and data. Thank you all for an hugely informative thread! Coincidentally this post by Ben Horton ([url="http://photocinenews.com/2010/10/22/nat-geo-shooter-ben-horton-compares-canon-glass-to-zeiss-glass/"]http://photocinenews...to-zeiss-glass/[/url]) went up two days ago and has been getting a lot of attention. The testing was far from scientific and the sample Canon images are presented on a much higher contrast scene than the Zeiss, which also shows green/purple fringing from CAs on certain edges.
Out of curiosity I checked and found that Photozone had in fact reviewed that lens and had shown the Zeiss to be not quite as strong optically as the Canon 85mm f/1.2 L.
Since its my understanding that medium format digital does not have AA filters, and has to have glass that can provide that native sharpness, wouldn't a lens designed for medium format theoretically be able to provide a higher quality image? Could it be that the AA on the FF and APS-C bodies work against the higher grade glass?
-Javier
[/quote]
First of all, take Ben Horton's "review" with a pinch or salt or two. He doesn't seem to know all that much about optics. For starters, he compares pineapples and cucumbers, as primes should never be compared with zooms - zooms almost always fare a lot worse (exceptions being Canon 70-200 F/4L IS, 70-200 F/2.8L IS Mk II, Nikkor 14-24 F/2.8). IMO, it is actually amazing that the 16-35 does so well against the Zeiss 18 F/3.5, which says more about the Zeiss than about the 16-35L (and it happens to be a well known fact that the ZE 18 isn't really all that great compared to glass in the same category). I have tested a bunch of Zeiss lenses myself, excluding the 50 F/2, 35 F/2 and 25 F/2, and personally I don't like Zeiss glass - do note that this is what it is about in the end: do you like the rendering or not - cooler colours, a lot of light fall-off towards the corners, way, way more than the Canon lenses I use myself. The really good Zeiss glass are the 35 F/2, 50 F/2 and 100 F/2, especially the latter, the rest are bettered easily by good Canon glass if you ask me. But again, that is personal.
Zeiss glass is good, generally speaking, but they need to be compared to similar Canon glass, and those are equally good, some are silghtly better, and vice versa, it is that simple.
BTW, I personally happen to know a NatGeo photographer who uses Canon and Canon glass, those awful L-zooms, to great effect (and I am talking about the shorter lenses here), and I also know that several NatGeo photogrpahers uses Olympus 4/3 cameras and lenses.
Medium format lenses generally have lower resolution than 35 mm format lenses, so they would generally not provide higher image quality on dslrs. However, they are fun to play with, especially when used with TS-adapters (they have a much larger image circle after all). And no, the AA filters do not work agianst the higher grade glass, even though it seems that way. Without them, you actually get spurious resolution, details which don't exist, and moiré, which can't be cleaned up by software, whatever anybody says - after the fact this literally is impossible, because the original data (the actual light rays falling onto the sensor) are no longer available.
What a lot of people still don't understand, is that every digital image needs sharpening, and with AA-filters a little more than without one. However, when applied well you should get the same results as with out an AA-filter, minus spurious elements and moiré.
To (try and) keep a long story short: all world class glass, whether it is Nikon pro lenses, Canon pro lenses, Zeiss lenses, or Sony pro glass, is so good, you won't see a real difference in print, other than rendering characteristics. Anything else is PP skils, and for size, FF (better quality at large sizes). Lenses are better than they ever were before, and you won't be able to tell the IQ and optical differences apart when looking at any picture the size of, let's say, A4 prints, and smaller. The difference is really in the processing. I still have a few 60 cm X 90 cm and 40 cm X 60 cm prints on the wall, taken with the "lowly" 350D and 400D, with lenses like the 70-200 F/4L plus 2X extender, TS-E 24L (Mk I), and 100-400L, supposedly all not so great lenses or combinations. It is really in the end about the photographer, his or her vision, and the way that vision is worked out in the final picture. Anything that gets good or better grades here on Photozone in tests, essentially is a fabulous lens to take pictures with.
Kind regards, Wim
Gear: Canon EOS R with 3 primes and 2 zooms, 4 EF-R adapters, Canon EOS 5 (analog), 9 Canon EF primes, a lone Canon EF zoom, 2 extenders, 2 converters, tubes; Olympus OM-D 1 Mk II & Pen F with 12 primes, 6 zooms, and 3 Metabones EF-MFT adapters ....