Fred Miranda wrote: jhinkey wrote: jhinkey wrote:
Just got back from taking some quick hand held comparison shots between the 90/2.8Sig and:
- 85/4ZM
- 90/3.5 CV
- 85/1.8G
I can say that the manual focus experience is mediocre. Build quality is great, but you turn the focus ring forever and very little happens. I suppose that might be good as once you get the focus, minor bumps to the focus ring won't change anything. The focus distance scale in the viewfinder with this lens, as with many lenses, is useless.
Quick full image/center/right/left wide open manually focused.
First glance they are not bad. Haven't checked the corners. Time for dinner.
I must have messed up the focus for the f/4 and f/5.6 shots that followed the f/2.8 shots I showed above as they are less sharp. I re-focused between aperture settings to make sure there was no focus shift going on as the aperture was stopped down.
I must say that I find this lens difficult to accurately manually focus because you turn the ring a lot and hardly anything happens, thus you'll turn it to get to critical focus and then you turn it too much because nothing is happening it seems or at least focus is changing very very slowly.
Also, when in AF mode on my A7RIII at least when you turn the focus ring it doesn't cause the camera to jump into fine AF mode with the + in the middle of the magnified view. Seems this lens will need some firmware updates. I haven't tried it yet with my A7C.
If the MF focus system is similar to the other Sigma I series, focus throw is very large at around 270 degrees. It's great to focus on fine detail but it takes a lot of rotating. It feels linear but focus throw also varies depending on ring rotation speed.
Interestingly it seems that focus throw and other MF settings can be tweaked with the Sigma USB HUB but it's only available for the L-mount. (Not E-mount).
I tried the MF focus thrown with my 90/2.8i on Sony A7C and the focus throw is around 270 degrees if I turn the focus ring fast. But if I turn the ring slowly (like I normally would when I'm trying to fine-tuning optimal focus), focus throw is much longer. It's hard to measure accurately but it's more than 720 degrees. If it was consistently 270 degrees regardless of the speed of turning the focus ring I think it would be much better...
Would be nice if there was a way to tweak the behavior for the E-mount versions of the lenses as well.
Oct 03, 2021 at 11:09 PM
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