Sony A9 III Soft focus on subject w/ A9iii

[akira5]

Hello, I've been doing a lot of concert photography. I notice at times the subject is soft and the background is sharper. I don't know if the
Focus area shifts more toward the BG instead of the subject.
My settings are AF-C, center metering, Medium to small spot focus area, On crowd shots I take the face recog off and only use it for Indiviuals.
There was decent light at the show. I've included some unedited images to show my issue. I used a sony GM 12-24 lens amy A9M3 for these pics. Also when doing group shots of people what is the best
focus area setting?

Any advice is appreciated

 

[Angus Cameron]

Hi Akira,

I think you may be suffering from slight motion blur rather than a focusing issue, try increasing your shutter speed. I’d try 1/400th at least for this.

 

[PhotoRon]

Could be subject movement, since the background looks ok.
On the A9III there is a Playback setting to allow you to see (on playback in camera) where the focus spot was. Find the menu and see if it is enabled. That may help with your analysis.
I still like using medium spot focus, and put it on the face I want.

 

[Richard A]

That's what I was thinking...

 

[akira5]

Hi Akira,

I think you may be suffering from slight motion blur rather than a focusing issue, try increasing your shutter speed. I’d try 1/400th at least for this.

Thanks for the reply on the blur. I've been doing a shutter of 250 with on camera flash indoors. I'd like to go up to a higher speed like 400, but won't that cut down my light and push my flash?

 

[akira5]

Could be subject movement, since the background looks ok.
On the A9III there is a Playback setting to allow you to see (on playback in camera) where the focus spot was. Find the menu and see if it is enabled. That may help with your analysis.
I still like using medium spot focus, and put it on the face I want.

Thanks, I have that playback option enabled to see the focus point. I'll check it. I was thinking the focus might have moved or I moved and the spot went more toward the background. In a live music setting anything wider than medium spot will pick up microphone stands or speakers and focus on them. when I used to use wide focus area, that always happened.
In a live music setting which spot size do you think would work best?

 

[Angus Cameron]

HI Akira,

Unfortunately your images have been cropped so it makes it a little more difficult to judge the field of view and your distance to subject.
Anyway lets look at your 1st image as this is using f5.6 so the shallowest depth of field. Assuming your subject was 2.4m from you then your depth of field would be from 1.2 meters to infinity. If the focus point was on the background at say 6m then the depth of field would be 1.7m to infinity. That why think it's less likely to be a a focus point issue.
Using flash for fill is fine and you don't need to worry about HSS flash with the camera you have. If you are using TTL on the flash you might want to use the flash adjustment on the camera and pull the flash back 1 stop maybe even 2. You can also afford to open up your aperture for instance with f2.8 and focusing on your subject at 2.4m then your depth of field is from 1.6 to 4.8m. This will allow you to increase your shutter speed even further. Had you used this setting when taking your image then you would have had 2 stops in hand and could have maintained the same exposure whilst increasing your shutter speed from 250 to 1000. This would almost certainly have eliminated motion blur.