5dMk2 keeps changing Shutter/ISO when recording

[conf]

hi there,

my Canon 5D Mark II recently started changing the ISO and the shutter speed slightly when hitting the record button. this is something completely new that's never happened before, I can't remember changing the settings at all but even so I did a reset of all the settings and it still does the same.

it's in Manual mode, of course, and I face the camera towards a dark corner with an ISO of 640 in this case and it shows in the LiveView what it looks like at 1/50 shutter and 640 ISO, but the second I hit record the camera starts brightening the shot automatically by raising the ISO up to 4000+ ISO and changes the shutter speed to 1/33

does anyone know why it's doing this and how I fix it?

thanks in advance

[Waddizzle]

Even though the ISO may read out as 640, check to be sure that ISO isn't set to Auto.  What is your aperture setting?

[conf]

I've checked several times, even set it to Auto and then set it back to a constant ISO, same thing. Aperture is at 2.8 which is as low is it can go.

[Waddizzle · Accepted solution]

I've checked the manual.  ISO defaults to AUTO in Movie Mode.

The shutter speed should not be changing once you have set it manually, not unless it conflicts with the video frame rate.

You will also want to check [Live View/Movie Func. Sset].

The above setting can cause an automatic exposure change.

[conf]

Thank you! It was set to "Exposure simulation", I changed it to "Movie display" instead and that got rid of it!

Much appreciated!