Sigma 30mm f/1.4 Focusing Problems

Richard Crowe

TalkEmount Top Veteran
Joined
Sep 14, 2018
Messages
537
I tend to see some focusing problems with my Sigma 30mm f/1.4 Focusing Problems. The focusing at times tends to go in and out and sometimes results in images that are not in focus.

I have been shooting in single shot mode with wide area. I have face detect selected and will get focus squares on peoples faces but, then the lens will hunt and I often end up with an OOF image. This happens both indoors in lower light levels and outdoors.

This image was shot with my A6500 using ISO 320, f/5.6 at 1/250 second. There were focus squares on two of the faces but, the focus was going in and out and it looks like the lens has back focused because the greenery behind the subjects seems to be in better focus...
Subscribe to see EXIF info for this image (if available)
 

WNG

TalkEmount Hall of Famer
Joined
Aug 12, 2014
Messages
4,072
Location
Arrid Zone-A, USA
Real Name
Will
Hopefully someone with your combo has some advice to your focusing issue, sounds odd.
I would suggest AF-C instead of AF-S, when using wide and face detect. From the shot, I assume it was a timer portrait. So, the camera must 'guess' on which face is the desired one to focus on. And any movement may lose focus. The fast lens means there's a longer throw of range to focus, thus hunts more in AF-S. Continuous focus should cut down the amount of focus hunting. I'd try an aperture of f/2.8-5.6 to give a sharper dof for the AF system.
 
Last edited:

Richard Crowe

TalkEmount Top Veteran
Joined
Sep 14, 2018
Messages
537
I think that there might be a problem with this lens. At times it locks in focus using either AFC or AFS and at other times it hunts in and out. This occurs with both my A6400 and A6500 - so it is not the camera that is at fault...

I have had problems focusing with my Sigma 19mm f/2.8 lens, which I am told should only be used in center focus.

I have never been absolutely happy with the AF capabilities of Sigma lenses as a whole on DSLR cameras. As an example, the Sigma 85mm f/1.4 lens is a beautiful glass but, it will often not nail focus. I was hoping that this would be solved with the mirrorless line.

I simply cannot live with on again - off again auto focus. The reason I bought a Sony A6500 and an A6400 is their great AF capabilities.

My solution is to get rid of the Sigma lenses and to shoot with nothing but native Sony glass in AF or vintage glass in MF.
 

WNG

TalkEmount Hall of Famer
Joined
Aug 12, 2014
Messages
4,072
Location
Arrid Zone-A, USA
Real Name
Will
I've had similar focus hunt on my 19mm f/2.8. But expected it somewhat from these older designs.
 

Latest posts

Links on this page may be to our affiliates. Sales through affiliate links may benefit this site.
TalkEmount is a fan site and not associated with Sony Corporation.
Forum post reactions by Twemoji: https://github.com/twitter/twemoji
Copyright © 2011-2019 Amin Forums, LLC
Top Bottom