JVJL wrote:
BTW, my samples were shot with a 7R2 with the latest firmware. I set my camera to manual focus and played around with different focal lengths and apertures. From a quick and dirty check, using the back of the camera, 24mm - 50mm focus shift seems relatively minor. On my copy the issue seems to become noticeable from 50mm - 105mm. As shown in my samples the focus shift is significant even one stop down at f/5.6.
Mine was most notable from 50-105mm too on my MkIII. Never tried it on MF but on AF-S it was very noticeable even through the viewfinder. Really disappointed because on AF-C there seemed to be no issues. Regardless sent mine back before my return period was over. Sad too because it was my second copy with this issue. Tired of gambling on getting a good copy. When the issue is resolved I will buy another. Hopefully Sony is aware there is a problem. I documented my issues when I returned it and certainly enough are being returned or exchanged for them to know about it. At least I would think so.
Oh sorry, this is really not good.
Thank you for samples. I decided to keep my 24-70 GM. I don't want to play game with QC at all. I have no time to buy/test/exchange...
Feb 02, 2018 at 09:22 PM
Steve Spencer Offline • • • • • • • Upload & Sell: On
jamato8 wrote:
X number of lenses are normally checked in a line but in this case, I am surprised that Sony isn't giving far more attention to QC. This has to be one of the worse rollouts of a product I have seen. Come on Sony.
What makes you think X number of lenses are checked in a line? I don't think that happens with anything but very expensive lenses like the Cine lenses at Zeiss and Leica M lenses. I think none of the typical DSLR and mirrorless lenses are checked in production.
Has anyone tested this lens using AF-A? Perhaps, when using AF-A, AF switches from AF-S to AF-C in situations where focus shift may occur. Seems unlikely, but who knows. My conjecture also doesn't account for the apparent difference in focus shift among different copies of this lens. Might be worth checking anyway.
Chris Crevasse wrote:
Has anyone tested this lens using AF-A? Perhaps, when using AF-A, AF switches from AF-S to AF-C in situations where focus shift may occur. Seems unlikely, but who knows. My conjecture also doesn't account for the apparent difference in focus shift among different copies of this lens. Might be worth checking anyway.
For me, AF-A gives the same result as AF-S, which on my copy, is no good! Was worth checking however so thanks!
Michael Everet wrote:
What few comments that have come out so far have been this zoom is good, but no G master. What about comparing it to the other G zooms. I have looked at the images available from various sources, the most samples being posted on Dpreview, and tend to agree.
I don't have enough experience with the FE 24-70/4 zoom to get a sense how it compares there. That seems to be its closest sibling. While no scientific comparisons can be done at this time, does anyone know the 24-70/4 well enough to offer an opinion whether the samples look like an IQ improvement over the 24-70-- ignoring of course difference in coverage and other factors?...Show more →
Hi Michael, what are you planning to use this lens for? What are your criteria? For example I used to be a zoom merchant, then switched to AF primes and am now mainly in the world of MF primes. I'm currently in the UK with MF 28 and 35 and AF 55 primes. Rob
It’s hard to understand how I have the very same lens purchased at B&H and with none of these AF-S problems or any focus shifting issues. After reading of all the problems that some have reported with their lenses I have been testing mine over and over thinking that it is going to develop this same problem but so far after running dozens of separate tests over the last week I can’t recreate any of these focus shifting problems. I’m part relieved and part perplexed over this whole ordeal! Is my currently perfectly working lens going to suddenly develop these issues while out shooting somewhere? I certainly will be somewhat nervous of that occurring and messing up some shots that I will be super bummed I missed. I hope Sony gets everyone some answers on what is causing this problem and soon. When the lens works properly it really is a fantastic piece of gear.
rji2goleez wrote:
Here's my crude handheld test but it shows how bad it can be. In each shot, I set the aperture, focused away from target and re-focused on the E-mount.
Bob, I'm curious...
in the 105mm/ƒ8 shot, it looks like quite a lot of shift. About how far forward would the box have to move to be in focus?
Chuck Coyne wrote:
It’s hard to understand how I have the very same lens purchased at B&H and with none of these AF-S problems or any focus shifting issues. After reading of all the problems that some have reported with their lenses I have been testing mine over and over thinking that it is going to develop this same problem but so far after running dozens of separate tests over the last week I can’t recreate any of these focus shifting problems. I’m part relieved and part perplexed over this whole ordeal! Is my currently perfectly working lens going to suddenly develop these issues while out shooting somewhere? I certainly will be somewhat nervous of that occurring and messing up some shots that I will be super bummed I missed. I hope Sony gets everyone some answers on what is causing this problem and soon. When the lens works properly it really is a fantastic piece of gear....Show more →
You know what, Chuck, I feel the same way. I am also perplexed as what may cause the difference, which is almost like either black or white without any grey in between. I tested mine a few times more and on different bodies to make sure. So far the results have remained the same.....fortunately.
The issue is so easy to detect and you can evaluate it right in the camera without having to download the files to the computer to see it. I am convinced that the issue will be fixed by Sony before too long.
RCicala wrote:
To clarify the above, this is a typical field I'm seeing for this lens. Focused dead (horizontal black line) in the center a test chart shows a 2-D even amount of sharpness from edge to edge. Focused to the right or left, and depending on focusing direction, you might stop at either arrow in which case edge-to-edge sharpness would suck.
This doesn't account for the focus shift issues being reported, but I point it out because it will affect some photographs too.
I do find this graphic a little disturbing. I just returned a 12-24 for a linear degradation of image quality from the center to the right edge. This may explain what was happening.
Is this tilted focal plane common in lenses you test?
timballic wrote:
Are the faulty lenses equally faulty on whatever A7x they're used on, or is it specific to certain camera models?
I've been wondering this too. My 24-105 is fine on my a7rii, although its focusing behavior (wide open vs stopped down) matches what has been described.
Yes, I'm also wondering if the presence of the issue is dependent on camera, and maybe also firmware level. This thread at dpreview indicates that the A7Rii and other older A7X cameras focus stopped-down on zoom lenses, but also indicates the behavior may have changed at some firmware level: https://www.dpreview.com/forums/post/58212556
Chuck Coyne wrote:
It’s hard to understand how I have the very same lens purchased at B&H and with none of these AF-S problems or any focus shifting issues. After reading of all the problems that some have reported with their lenses I have been testing mine over and over thinking that it is going to develop this same problem but so far after running dozens of separate tests over the last week I can’t recreate any of these focus shifting problems. I’m part relieved and part perplexed over this whole ordeal! Is my currently perfectly working lens going to suddenly develop these issues while out shooting somewhere? I certainly will be somewhat nervous of that occurring and messing up some shots that I will be super bummed I missed. I hope Sony gets everyone some answers on what is causing this problem and soon. When the lens works properly it really is a fantastic piece of gear....Show more →
I’m in the same boat Chuck. Keep worried mine is going to start doing it. My original thought stays the same , somehow I’m thinking a element group gets out of whack when it goes to 105mm.
I wonder if someone that has the problem could try zooming very slow to 105 than try it at a faster rate. One other question I had was this shutter/ focusing off the same release or does it do it as well with back focus.
For those who keep wondering if it's firmware keep in mind this issue occurs with manual focusing, with the shift occurring with only a change of the aperture after manually focusing. The only way this could be firmware related then is if the camera or lens are intentionally shifting the focus element in response to the aperture change. That seems highly unlikely.
As for how this could be copy specific, this could related to the positioning of an element or the polishing/molding of one of the aspheric elements, although that's just a wild guess at his point. Hopefully Brandon will stop by and weigh in. See this thread for some graphics on focus shift.
