EOS 750D Movie Mode random auto focus adjustment

[DToleman]

Howdy,

I have a 750D with Tamron SP 24-70mm lens

While shooting video, the camera suddenly re-focuses creating a white out or a black out for 1/2 second

Here are two examples of problem.

https://youtu.be/_ilV-dM5x6w

https://youtu.be/ISYRZ8teky0

I have tried a range of solutions - turned off auto-focus on camera and lens, set white balance to indoor, reset the camera. 

It does not matter what location or light settings I am in, this keeps happening

Can anyone please tell me what causes this and how to fix it

Thank you 

[DToleman]

Hi KV

Yes, the mirror does flip.

[Waddizzle]

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@DToleman wrote:

Hi KV

Yes, the mirror does flip.

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What are the sizes of the video files?  Make sure all of the image correction settings are disabled, and WB is manually dialed in to a color temperature.

If the lens is in manual focus, and the camera is not in any automatic mode, I do not see how or why it would randomly auto focus or adjust exposure.

[kvbarkley]

That is why I suspected a shutter button issue.

[DToleman]

Hi KV,

A bit of time away from this problem but now coming back to it. Could you tell me what you mean by disable image correction settings. I just want to make sure I am disabling what you think I should.
Cheers. David

[kvbarkley]

That wasn't me, but he measn things like peripheral image correction and Digital Lighting Optimiser.