p.4 #1 · Rolling review: Zeiss Vario-Tessar T* FE 4/24-70 ZA
That still looks worse to me...sorry. And the fact that it's at BEST 'close' to the same performance is still a little embarrassing. For a modern Zeiss lens at that price point...it should demolish something like the 12-32 at f/11. There's still CA even after reduction. The 12-32 has no CA correction done in the RAW conversion.
Here's another 100% crop of the lower left extreme corner of the frame of another shot at 12mm, f/7.1.
It's not perfect, but it's certainly usable, and the softening is really only the last very small percentage of the frame, where the sharpest part of the crop you posted is only as sharp as the softest part of the 12-32 crop, at least by my eye. I'm also focused a fair bit into the frame, and this crop is from the extreme foreground (so not even the focus point or near to it).
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p.4 #2 · Rolling review: Zeiss Vario-Tessar T* FE 4/24-70 ZA
alundeb wrote:
I don't think the A-mount Zeiss 24-70 2.8 is noteworthy better in the extreme corners at 24 mm.
The highly regarded Distagon 25 mm f/2 ZE/ZF also has extreme corner smearing like this.
From the examples that Phillip has shown it seems that the Sony/Zeiss FE mount 24-70 f/4 is worse than the Zeiss ZE/ZF 25 f/2, mainly because he has shown that the Sony/Zeiss 24mm f/2 a-mount prime is a lot better than the zoom and the A-mount 24 f/2 and the ZE/ZF 25 f/2 seems to have quite similar corner performance. I also expect the A-mount 24-70 f/2.8 would be better and it would be noteworthy. The Sony/Zeiss 24mm f/2 has an advantage over the A-mount zoom, but not as much as it seems to have here over the FE mount zoom. All of this is totally consistent with the MTF charts as well. So as in the post you wrote above, people probably shouldn't make too much about the weak corners at 24mm with the new zoom, but in my view they shouldn't gloss over the weakness either. The astigmatism is quite extreme, but at least it clears up by 28mm or so.
p.4 #4 · Rolling review: Zeiss Vario-Tessar T* FE 4/24-70 ZA
Soft corners are kind of the name of the game for most of these midrange f/4 zooms on FF at 24mm. The Canon 24-105 and Nikkor 24-120 have the same issue and it hasn't stopped a lot of people from making some great images with them. Whether it's worth the compromise to any one individual is of course up to that individual.
p.4 #6 · Rolling review: Zeiss Vario-Tessar T* FE 4/24-70 ZA
alundeb wrote:
I disagree with that. At least you have now demonstrated that the 12-32 gets blurry in the extreme corner too.
We'll have to agree to disagree then. It's also worth noting that I never said the 12-32 was razor sharp at the extreme corner...I said it was better than the 24-70, and I made that comment after seeing this image...and I think that it was valid based on that. In any case, if the 24-70 works for you, then get it. I personally would be a bit bummed by this performance in a high end lens. This corner performance isn't a big deal wide open, and it's only at the widest end...but at f/11 it's a bit of a disappointment.
p.4 #7 · Rolling review: Zeiss Vario-Tessar T* FE 4/24-70 ZA
Phillip Reeve wrote:
the ZA2470 has significant astigmatism, so while sagittal strutures are are tangential ones are not. In that crop there are manily sagittal one.
If it really is astigmatism, you should be able to get tangential structures sharp by focusing on them, and the sagittal structures should then be out of focus.
p.4 #8 · Rolling review: Zeiss Vario-Tessar T* FE 4/24-70 ZA
alundeb wrote:
If it really is astigmatism, you should be able to get tangential structures sharp by focusing on them, and the sagittal structures should then be out of focus.
voila: edit: I read you porst again and will check tangential structures tomorrow. saggital by reevedata, on Flickr
I am pretty sure that I manually focused this shot on the lower right corner: DSC00003.jpg by reevedata, on Flickr
the lens at 24mm shows a wider field of view than the ZA 2/24, I think this is to compensate for the distortion correction: Corner by reevedata, on Flickr
p.4 #10 · Rolling review: Zeiss Vario-Tessar T* FE 4/24-70 ZA
snapsy wrote:
For those asking how the Sony might compare to a standard 24-70, I performed a test series with the Tamron 24-70VC on my D600 today. The weakest focal length on the Tamron is 35mm. Note that for the corner shots I had to tilt the lens because I chose to use the same subject as the center/edge, so there's some distortion on 24mm - 35mm.
p.4 #11 · Rolling review: Zeiss Vario-Tessar T* FE 4/24-70 ZA
Steve Spencer wrote:
I agree with your point here alundeb. It makes a very nice 28-65mm lens. I think many people will find it useful, as in this range it has quite decent IQ for an f/4 zoom with good contrast, decent bokeh, and quite good sharpness. People should know about its weaknesses at both ends, however.
I wish it was possible to set a hard limiter at 65 mm focal length. Cropping to 70 mm FOV will give a better image than zooming in to 70 according to Phillip's test. Even knowing about the limitation, 70 mm will be used by accident sometimes.
The weakness at 24 mm is not so critical, because it only affects 4% of the image area, and the least important 4%.
Feb 11, 2014 at 02:51 AM
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p.4 #12 · Rolling review: Zeiss Vario-Tessar T* FE 4/24-70 ZA
alundeb wrote:
I wish it was possible to set a hard limiter at 65 mm focal length. Cropping to 70 mm FOV will give a better image than zooming in to 70 according to Phillip's test. Even knowing about the limitation, 70 mm will be used by accident sometimes.
The weakness at 24 mm is not so critical, because it only affects 4% of the image area, and the least important 4%.
Actually if you look at Phillip's image on page 2 in which he has the whole swath from the centre to the corner the fuzziness extends way further than 4%, much more like 10%. My take is that 24 would be useful for closer in shooting and most mid range distances, but would be mostly useless for landscapes. At least for the way I shoot.
I would actually much prefer 70mm for landscapes. It is less sharp, but the sharpness is even and for a lot shots (particularly if you didn't need a full resolution print) that could work just fine, but the drop off in sharpness from the centre to the corners at 24mm would be quite noticeable even in a pretty small print.
p.4 #13 · Rolling review: Zeiss Vario-Tessar T* FE 4/24-70 ZA
Steve Spencer wrote:
Actually if you look at Phillip's image on page 2 in which he has the whole swath from the centre to the corner the fuzziness extends way further than 4%, much more like 10%. My take is that 24 would be useful for closer in shooting and most mid range distances, but would be mostly useless for landscapes. At least for the way I shoot.
I would actually much prefer 70mm for landscapes. It is less sharp, but the sharpness is even and for a lot shots (particularly if you didn't need a full resolution print) that could work just fine, but the drop off in sharpness from the centre to the corners at 24mm would be quite noticeable even in a pretty small print....Show more →
Do you mean 10% of the image height or 10% of the image area? 10% of the image area corresponds to 22% of the image height.
One of the problems with 70 mm, is that it has more curvature of field in addition to general softness. It is much more difficult to get a uniform image from centre to extreme corner at 70 mm than 65 if you look at the whole swatches.
p.4 #14 · Rolling review: Zeiss Vario-Tessar T* FE 4/24-70 ZA
alundeb wrote:
If it really is astigmatism, you should be able to get tangential structures sharp by focusing on them, and the sagittal structures should then be out of focus.
Both should be possible to get in focus, at different distances though.
p.4 #15 · Rolling review: Zeiss Vario-Tessar T* FE 4/24-70 ZA
I can't help but suspect corner issues with wides are at least partly to blame on the thick sensor toppings that Sony loves so much, not only on the A7/R but also the A900/A99.
This lens is not the only one with weak corners, even the ZA 24/2 isn't that great. One would tend to think Zeiss is unable to design a wide with sharp corners
p.4 #16 · Rolling review: Zeiss Vario-Tessar T* FE 4/24-70 ZA
edwardkaraa wrote:
I can't help but suspect corner issues with wides are at least partly to blame on the thick sensor toppings that Sony loves so much
Well if that was the case we should see worse corners with a Zeiss 2.8/21 for example than on a 5d or D800, I don't know any tests which suggest that but I haven't read too much about the topic.
Feb 11, 2014 at 08:33 AM
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p.4 #17 · Rolling review: Zeiss Vario-Tessar T* FE 4/24-70 ZA
alundeb wrote:
Do you mean 10% of the image height or 10% of the image area? 10% of the image area corresponds to 22% of the image height.
One of the problems with 70 mm, is that it has more curvature of field in addition to general softness. It is much more difficult to get a uniform image from centre to extreme corner at 70 mm than 65 if you look at the whole swatches.
What I mean is 10% of the linear distance from the centre to the corner (at least to me that is what it looks like in Phillip's test). This is of course a bit of a subjective judgment. The drop in sharpness falls off from what looks to be about 30% of the linear distance all the way to the corner. To my eye from about 10% it is bad enough to be problematic. From Phillip's pictures to me it looks like the bad area would extent from the corner to about a 1/3 of the way down the short side (on both sides leaving only about 1/3 of the short side unaffected) and would extend about a quarter of the way down the long side (again on both sides so about half the long side would not be affected). These are approximates and subjective--basically eyeballing it. Neither the 10% number nor how far it extends on each side are meant to be precise.
p.4 #18 · Rolling review: Zeiss Vario-Tessar T* FE 4/24-70 ZA
Phillip Reeve wrote:
Well if that was the case we should see worse corners with a Zeiss 2.8/21 for example than on a 5d or D800, I don't know any tests which suggest that but I haven't read too much about the topic.
As far as I understand, Sony uses thicker sensor toppings than any of the competition. I don't have the exact numbers, but it seems Canon sensor toppings are as thin as Leica M cameras, very thin. I don't know about Nikon, but for sure not as thick as Sony.
I fail to understand the need for such thick glass, especially that on the A7/R, Sony has every incentive to use as thin as possible glass covers.
p.4 #19 · Rolling review: Zeiss Vario-Tessar T* FE 4/24-70 ZA
Thanks, Steve, then we agree on how much the really problematic blur extends. 10% linear distance in each corner cuts out approximately 4% of the image area.
Feb 11, 2014 at 08:52 AM
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p.4 #20 · Rolling review: Zeiss Vario-Tessar T* FE 4/24-70 ZA
edwardkaraa wrote:
I can't help but suspect corner issues with wides are at least partly to blame on the thick sensor toppings that Sony loves so much, not only on the A7/R but also the A900/A99.
This lens is not the only one with weak corners, even the ZA 24/2 isn't that great. One would tend to think Zeiss is unable to design a wide with sharp corners
But in Phillip's test the ZA 24 f/2 is quite a bit better than this e-mount 24-70 f/4, so some of it has the be the zoom as well.
