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A7II Autofocus in Video Questions


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I have recently bought an A7II and I am loving it. I have never got into video before, but would like to give it a go. I have a question about the autofocus in video though.

 

When in video mode I am locked into either AF-C or MF, but when I press the shutter button in AF-C it locks focus like AF-S does in stills mode. If I use the 'Center Lock-On' autofocus it tracks (poorly) until I press the shutter button (when again it locks focus and stops tracking), whereas it tracks really well in still mode with the shutter half pressed.

 

Is this right? Am I missing something in the settings? Should I be using 'Center Lock-On' without pressing the shutter button to autofocus in video? Should I just give up with autofocus in video altogether?

 

Any help/opinions would be appreciated.

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The best settings for autofocus in video depend on what you are shooting. If you're shooting people use WIDE focus area and AFC with FACE REGISTRATION turned on. You can/should prioritize the order of recognized faces if necessary. For objects AFC with CENTER focus area and FACE REGISTRATION off would work better.

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The best settings for autofocus in video depend on what you are shooting. If you're shooting people use WIDE focus area and AFC with FACE REGISTRATION turned on. You can/should prioritize the order of recognized faces if necessary. For objects AFC with CENTER focus area and FACE REGISTRATION off would work better.

 

Thanks, I'll try this out tomorrow and see if I get better results.

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To track one person (or object) in video mode, turn off CENTER LOCK ON AF and use FLEXIBLE SPOT LOCK ON AF instead. Put the spot on the person (object) you want to track and the AF will stick to that person (object) when you move the camera as long as the person/object is in the frame. If they leave the frame and then return the lock on AF should re-engage.

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To track one person (or object) in video mode, turn off CENTER LOCK ON AF and use FLEXIBLE SPOT LOCK ON AF instead. Put the spot on the person (object) you want to track and the AF will stick to that person (object) when you move the camera as long as the person/object is in the frame. If they leave the frame and then return the lock on AF should re-engage.

 

I don't think you can select 'Flexible Spot Lock On AF' in video mode, at least I can't.

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It is actually constantly focusing in AF-C when doing video. No need to touch the shutter button. It's quite good, as it is focusing very slowly, softly and doesnt hunt. It sometimes takes a while if the scene is too dark or just lacks contrast. But its okay for a simple video.

For everything more serious, I recommend manual focusing.

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It is actually constantly focusing in AF-C when doing video. No need to touch the shutter button. It's quite good, as it is focusing very slowly, softly and doesnt hunt. It sometimes takes a while if the scene is too dark or just lacks contrast. But its okay for a simple video.

For everything more serious, I recommend manual focusing.

 

Thanks, that makes a lot of sense.

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  • 4 years later...

I'd stay away from the shutter button to focus when rolling video as it introduces a brief jump / hiccup / stutter while it locks on. Here's my solution (A7Sii)

Continuous AF works swell (Turn off when shooting HFR as it introduces a visual jitteriness not seen at standard frame rates but will on slow motion) but set up camera for back button focus. This way you can rack focus, in or out, by holding button down to enter manual focus, rotate out of focus, then letup whereby it acquires focus smoothly. Or reverse the procedure then say adios forever to those focus jumps pressing shutter button gives you.

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5 hours ago, VTC said:

I'd stay away from the shutter button to focus when rolling video as it introduces a brief jump / hiccup / stutter while it locks on. Here's my solution (A7Sii)

Continuous AF works swell (Turn off when shooting HFR as it introduces a visual jitteriness not seen at standard frame rates but will on slow motion) but set up camera for back button focus. This way you can rack focus, in or out, by holding button down to enter manual focus, rotate out of focus, then letup whereby it acquires focus smoothly. Or reverse the procedure then say adios forever to those focus jumps pressing shutter button gives you.

How I can setup the back button focus? I had it on my previous camera (Nikon D750) but don't know how to do it on this one. Also, if someone can explain what exactly is the DMF for? I'm a bit lost...

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