Autofocus darkens on 5D MK III? (Movie Mode)

Well, I'm really not using the movie-mode/function on my MK III, I'm more of a still-photographer.

BUT I would love to use it to do some filming sometimes, mostly vacation-stuff etc.

Only one problem, when using the AF (yes, I do know that I should use manual focus when filming, BUT that is way to much work for some quick filming...) the whole movie goes darken, and when I stop using it it goes back.


Is there anyway around this? Any settings prefered etc?

/Jocce

Have you got the video AF mode set to "Quick mode"?

rrblint wrote in post #16063048
Have you got the video AF mode set to "Quick mode"?

Don't have the camera here right now...have to check when I get home...


/Jocce

If so, then the mirror actually flips down so that the phase detection AF array that is normally used for viewfinder still photography can be used for Live View/Video photography. This will cause the Live View image to go completely black while AF is in progress.

If the image just dims, rather than going completely dark, it could also be "Exposure Simulation" used in conjunction with manual exposure where underexposure has been set that is causing the problem.

It was not on Quick Mode.


And the problem also shows in the movie-file when watching it on the computer.
Does anyone else have this?
Do I have to use any special setting for this to go away?


/Jocce

It sounds like the preview is with the lens wide open, then when you start shooting the lens is stopping down to whatever the F stop has been set to.
To get the best out of the movie mode set the camera to manual mode, shutter speed double the FPS (so if shooting PAL at 25fps or 24fps set the shutter to 1/50), f stop and ISO to suit. This will give yo ua more consistent image on the LCD and actual footage.