p.5 #1 · 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.
That would depend upon the optical design. The Zeiss 21 is a pretty darn big lens. I imagine Sony wanted to avoid building a zoom as big as a traditional SLR zoom....and this is the result.
Sony really seems to have created unnecessary problems for themselves by going with the thick cover glass on the A7r. It would be interesting to know if this was done in order to use off the shelf parts - and avoid cost - or to make sure the A7r would NOT perform well with certain other glass so users would be much more likely to buy native lenses from Sony/Zeiss(and I'm running away as I type this!).
Feb 11, 2014 at 08:58 AM
Steve Spencer Offline • • • • • • • Upload & Sell: On
p.5 #2 · Rolling review: Zeiss Vario-Tessar T* FE 4/24-70 ZA
alundeb wrote:
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.
I does look like we agree about how much of the image is affected, but it seems we disagree about whether that would be something that would bother us. For a landscape lens to me at f/11 this is too much of this image affected. It would in my mind significantly affect most of the shot I would want to use it for, YMMV.
p.5 #3 · Rolling review: Zeiss Vario-Tessar T* FE 4/24-70 ZA
Steve Spencer wrote:
I does look like we agree about how much of the image is affected, but it seems we disagree about whether that would be something that would bother us. For a landscape lens to me at f/11 this is too much of this image affected. It would in my mind significantly affect most of the shot I would want to use it for, YMMV.
I have no problems understanding your requirements. What saves me, is that I rarely compose images in the 3:2 aspect ratio. I use 5:4 and square quite a lot, and can then tolerate bad extreme corners to some degree without being less sensitive to blur and smearing.
p.5 #4 · Rolling review: Zeiss Vario-Tessar T* FE 4/24-70 ZA
Tariq Gibran wrote:
That would depend upon the optical design. The Zeiss 21 is a pretty darn big lens. I imagine Sony wanted to avoid building a zoom as big as a traditional SLR zoom....and this is the result.
Sony really seems to have created unnecessary problems for themselves by going with the thick cover glass on the A7r. It would be interesting to know if this was done in order to use off the shelf parts - and avoid cost - or to make sure the A7r would NOT perform well with certain other glass so users would be much more likely to buy native lenses from Sony/Zeiss(and I'm running away as I type this!). ...Show more →
p.5 #8 · Rolling review: Zeiss Vario-Tessar T* FE 4/24-70 ZA
Fred Miranda wrote:
The kit lens performs well.
I find the absence of CA especially noteworthy. When I tested it I thought that the Ca were corrected in camera, but the SEL2470z shows a minor degree of CA
p.5 #9 · Rolling review: Zeiss Vario-Tessar T* FE 4/24-70 ZA
Btw, for all my tests I focus once in the center and use that same locked focus for the edge and corner exposures for each focal length...so if there's field curvature it'll be reflected in the results.
p.5 #10 · Rolling review: Zeiss Vario-Tessar T* FE 4/24-70 ZA
snapsy wrote:
Btw, for all my tests I focus once in the center and use that same locked focus for the edge and corner exposures...so if there's field curvature it'll be reflected in the results.
That makes the 28-70 kit lens look even better.
I really like the color and contrast from the 24-70 f/4 samples I have seen. I have one on order and when it arrives, I will be able to compare it to my Canon 24-70L II.
It would be great to see a side-by-side FE 24-70 f/4 vs FE 28-70mm.
p.5 #11 · Rolling review: Zeiss Vario-Tessar T* FE 4/24-70 ZA
Is it possible you have a really poor sample. According to a GETDPI forum member, Lloyd Chambers reported the following:
"Conclusions. Result here are very pretty, very pleasing. The 24-70/4 Vario-Tessar offers high sharpness and excellent contrast, both overall and micro contrast, and right to the corners. It performs at a high level that is not disappointing relative to the best Canon 24-70mm L zooms."
p.5 #12 · Rolling review: Zeiss Vario-Tessar T* FE 4/24-70 ZA
I don't want to steal any of Lloyd's thunder by repeating his results here. I'll just mention that the quote above is at one focal length, at neither extreme of the zoom range. It's not a global assessment of the lens overall.
That said, I found his samples very pleasing and his assessment has me leaning towards getting one.
p.5 #13 · Rolling review: Zeiss Vario-Tessar T* FE 4/24-70 ZA
ebrandon wrote:
I don't want to steal any of Lloyd's thunder by repeating his results here. I'll just mention that the quote above is at one focal length, at neither extreme of the zoom range. It's not a global assessment of the lens overall.
That said, I found his samples very pleasing and his assessment has me leaning towards getting one.
p.5 #14 · Rolling review: Zeiss Vario-Tessar T* FE 4/24-70 ZA
Hi Philip
Great review. I don't doubt the thoroughness and accuracy of your testing one bit, but I do hope your results are partly due to sample variation. Below is a link to the review (mostly sample set) at SLR Club. The site is very slow to load but towards the bottom of the review there are a number of samples at 24mm and smaller apertures that indicate much better corner performance than your sample. Take a look at the ones with foliage and palm trees. It's not razor sharp but much better than your landscape example at 24mm. Take a look and see if you agree.
Sample link
ftp://rawdata.slrclub.com/lens/sony/1401_2470/DSC03598.JPG
Phillip Reeve wrote:
it is mine, no loaner.
If someone shows me significantly better results from someone else I will, try to replace it, but I fear that those corners at 24mm are not a copy specific problem.
@wfrank: My Minolta 35-70 is better in the corners but I had messed around with the adapter so the contrast in my Minolta shots is really low.
p.5 #15 · Rolling review: Zeiss Vario-Tessar T* FE 4/24-70 ZA
Steve Spencer wrote:
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.
No disagreement here, but the question remains open whether the zoom is optically inferior in the corners, or is it because it doesn't play nice with the thick sensor toppings. The only way to know is if a future A body has thinner sensor toppings like the Nex bodies that some have friendlier sensor toppings than others.
p.5 #16 · Rolling review: Zeiss Vario-Tessar T* FE 4/24-70 ZA
pixelreaper wrote:
...I do hope your results are partly due to sample variation. Below is a link to the review (mostly sample set) at SLR Club. The site is very slow to load but towards the bottom of the review there are a number of samples at 24mm and smaller apertures that indicate much better corner performance than your sample.
Sample link
ftp://rawdata.slrclub.com/lens/sony/1401_2470/DSC03598.jpg
From your review link, even the borders of the images (not just corners), are terrible even at F9 at medium to longer distance shots taken at 24mm's. Completely unacceptable imo...and I will add, it very well may due to the camera body (thick sensor glass) and not the zoom. In the end though, the reason does not matter for current users.
p.5 #17 · Rolling review: Zeiss Vario-Tessar T* FE 4/24-70 ZA
edwardkaraa wrote:
No disagreement here, but the question remains open whether the zoom is optically inferior in the corners, or is it because it doesn't play nice with the thick sensor toppings. The only way to know is if a future A body has thinner sensor toppings like the Nex bodies that some have friendlier sensor toppings than others.
I have read that A-mount and NEX E-mount cameras have an even thicker sensor cover glass. That being the case, perhaps, Sony kept the A7 series thickness pretty much unchanged allowing great compatibility with their previous lenses.
Image samples from Sony's A-mount Vario-Sonnar 24-70 f/2.8 ZA also show weakness at 24mm.
p.5 #18 · Rolling review: Zeiss Vario-Tessar T* FE 4/24-70 ZA
Dimitri.
I took the jpg into LR and viewed it at 100%. The base of the palm itself (bottom left corner) does show softness apposed to further up the trunk where it is sharper. Tip of palm leaf at top left is also similar. Subjectively I would say not too bad but the softness is there. Some lens correction followed by sharpening does improve the corners but again that's subjective.
p.5 #19 · Rolling review: Zeiss Vario-Tessar T* FE 4/24-70 ZA
Fred Miranda wrote:
I have read that A-mount and NEX E-mount cameras have an even thicker sensor cover glass. That being the case, perhaps, Sony kept the A7 series thickness pretty much unchanged allowing great compatibility with their previous lenses.
Image samples from Sony's A-mount Vario-Sonnar 24-70 f/2.8 ZA also show weakness at 24mm.
Some of the NEX E-Mount bodies played noticeably better with rangefinder wides than other models, notably the 16MP versions compared to the 24MP based NEX-7. Perhaps part of this was due to cover glass thickness differences between them?
The older ZA 24-70 was never great in the corners at 24mm's.
p.5 #20 · Rolling review: Zeiss Vario-Tessar T* FE 4/24-70 ZA
Fred Miranda wrote:
I have read that A-mount and NEX E-mount cameras have an even thicker sensor cover glass. That being the case, perhaps, Sony kept the A7 series thickness pretty much unchanged allowing great compatibility with their previous lenses.
Image samples from Sony's A-mount Vario-Sonnar 24-70 f/2.8 ZA also show weakness at 24mm.
Indeed, that was my experience with the Sony A900 and it was even advertized in Sony litterature that the sensor cover glass was further away from the sensor itself claiming this would make dust less visible. Of course we all know now how disastrous that would be on the performance of some lenses in the image periphery.
To be fair, at that time, that was not common knowledge. But the Sony engineers and designers should have known better.
On the other hand, Leica M bodies suffer from several issues caused by the thin cover glass, mainly that they are fragile and tend to break, and the insufficient IR filtration that causes some synthetic black fabrics to look purple and skin tones to look too pinkish, exaggerating blemishes and pimples.
I have used the ZA 24-70/2.8 on Minolta film bodies for a while and the film scans did not show any weaknesses in the corners that were too obvious on the A900, so I am personally very convinced it is the sensor cover not the lens itself.
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