mapgraphs wrote:
I'll add another observation to the 24-105 AF-S inconsistencies... At my first event with the 24-105, with the lens zoomed out to 105m and using AF-S - on some shots the point of focus was about 2-3m in front of the focus target which was about 10-12m distant (lower half of the frame). Didn't think too much about it since there were only a few shots that showed this. I wasn't really paying attention. Different day, tried some 105mm AF-S shots of a bird feeder through a double glazed door. First shot was okay but not crisp. Subsequent shots all had the point of focus about 1m in front of the feeder (lower third of the frame). Switched to AF-C and focus was consistently spot on with excellent sharpness. This doesn't feel like traditional focus-shift issue but more like a consistent miss-focus. (Camera is an a7ii with original firmware. Have not played with the menu settings.)...Show more →
It's likely the same focus shift issue others are seeing on some copies. You can tell for sure by manually focusing at f/4 on a distant subject using magnified view and take a photo. Then change to f/8 without refocusing and take another photo. You'll find the f/8 photo is OOF.
I suspect this is the reason why none of the more reputable testing sites have not published tests yet.
I refer to Photozone, LensRentals, DXO, Imaging Resource, LensTip....
If this issue is really caused by focus shift how can people have good copies ? True focus shift shouldn't be due to manufacturing variance. I'm frustrated because the lens seems so good otherwise. I hate playing the lens lottery. I'll probably return my copy and wait to see more evidence of good copies before trying my luck again. If I get some free time I'll post some crops which show how bad my copy is at 105 using AF-S. It's completely unusable.
JVJL wrote:
If this issue is really caused by focus shift how can people have good copies ? True focus shift shouldn't be due to manufacturing variance. I'm frustrated because the lens seems so good otherwise. I hate playing the lens lottery. I'll probably return my copy and wait to see more evidence of good copies before trying my luck again. If I get some free time I'll post some crops which show how bad my copy is at 105 using AF-S. It's completely unusable.
There are clearly a lot of good copies out there. It seems like it's almost 50/50 in this thread though. At least it's really easy to test and you know pretty quickly if you have the issue or not.
JVJL wrote:
If this issue is really caused by focus shift how can people have good copies ? True focus shift shouldn't be due to manufacturing variance. I'm frustrated because the lens seems so good otherwise. I hate playing the lens lottery. I'll probably return my copy and wait to see more evidence of good copies before trying my luck again. If I get some free time I'll post some crops which show how bad my copy is at 105 using AF-S. It's completely unusable.
I didn't think copy variance could cause focus shit either but I was told by a highly respected and well-placed source that this has occurred on other non-Sony lens models as well. It's absolutely focus shift rather than firmware since the shift can be observed by simply adjusting the aperture.
scalanc2 wrote:
I suspect this is the reason why none of the more reputable testing sites have not published tests yet.
I refer to Photozone, LensRentals, DXO, Imaging Resource, LensTip....
For me it was a combination of having trouble getting enough copies to test, and doing some extra tests trying to understand things. I've gotten the enough copies part done. Probably out next week.
Are people having more issues with lenses purchased at time of release? I wonder if any change was made in manufacturing or if this is simply variance that will persist..
Mine came in the mail today - I have the same problem as others in this thread. In AF-S mode I get very sharp photos at f/4 but at f/8 all images are out of focus. I get the same behavior if I put the camera on a tripod, manually focus at f/4 and then change the aperture - as the aperture gets smaller, the focal plane seems to move towards the camera.
If you were me, would you return it or wait a bit to see if there's a firmware fix of some sort?
Has Sony given anyone a helpful reply with regards to this issue?
Tested my second one thoroughly at about 3m both AF-S and MF (live preview off). No focus shift at any focal length (well, 24/50/70/105 anyway).
Can’t wait to see what Roger at Lens Remtals finds. And good observation by scalanc2 about few reviews posted... bet they are going back and forth with Sony.
Though my copy seems good at the moment, I worry (perhaps needlessly) about longer term reliability depending on the cause of the variance.
cswinton wrote:
Mine came in the mail today - I have the same problem as others in this thread. In AF-S mode I get very sharp photos at f/4 but at f/8 all images are out of focus. I get the same behavior if I put the camera on a tripod, manually focus at f/4 and then change the aperture - as the aperture gets smaller, the focal plane seems to move towards the camera.
If you were me, would you return it or wait a bit to see if there's a firmware fix of some sort?
Has Sony given anyone a helpful reply with regards to this issue?...Show more →
There are so many that Sony must be, has to be aware. I would call them and see if they have any idea if a FW update can fix this. Often the guys answering have no idea but there are a couple there that seem to have pretty good information. Worth a try or, send it back.
jamato8 wrote:
There are so many that Sony must be, has to be aware. I would call them and see if they have any idea if a FW update can fix this. Often the guys answering have no idea but there are a couple there that seem to have pretty good information. Worth a try or, send it back.
The only way a FW update could fix this is if Sony switched to stopping the aperture down for AF on the 24-105 in AF-S mode, like they do for the 24-70GM.
snapsy wrote:
The only way a FW update could fix this is if Sony switched to stopping the aperture down for AF on the 24-105 in AF-S mode, like they do for the 24-70GM.
But some lenses work fine and as in all the recent posts, some don't. It could be an update needed for a chip, which can be done but requires a different method of updating.
I’ve tested mine. Focus at f/4 @ 105mm and then stop down to f/8 and shoot. Sharp as a tack.
I have AF set to the rear AF button, so I know it isn’t refocusing.
Would seem to imply some mechanical difference.
-Tim
jamato8 wrote:
But some lenses work fine and as in all the recent posts, some don't. It could be an update needed for a chip, which can be done but requires a different method of updating.
I finally get home later today where my copy is waiting for me. I must say, I feel a little anxious to find out if my copy is a good one . . . to be continued . . .
Having 17 elements in 14 groups, including 4 asphericals and 3 of special glass there's got to be a lot of weird science in this lens. Sony obviously has to improve their production tolerances to match the technology in this lens. My advice: If you get a bad one send it back. As costs rise for the distributors and Sony something will get done.
I tried another series of shots, 105mm at f/4 with AF-S - without changing the aperture. First shot acquires focus, subsequent shots (same aperture and framing) loose focus. It's fairly (but not completely) consistent. There is no need to stop down to see the change (or loss) of focus at 105mm. Stopping down only makes it worse. Challenging lighting doesn't help either. This feels more like a software issue, not an optical issue.
mapgraphs wrote:
I tried another series of shots, 105mm at f/4 with AF-S - without changing the aperture. First shot acquires focus, subsequent shots (same aperture and framing) loose focus. It's fairly (but not completely) consistent. There is no need to stop down to see the change (or loss) of focus at 105mm. Stopping down only makes it worse. Challenging lighting doesn't help either. This feels more like a software issue, not an optical issue.
If you're having inconsistent focus at f/4 then that is a separate issue.
As to the original issue being discussed (focus shift @ 105mm), how can it be a software issue when the problem can be demonstrated by manually focusing the lens and just adjusting the aperture?
