With the 70D in movie mode and shooting manually how do folks deal with exposure compensation?

[Kelleytoons]

The question basically says it all -- I have ISO set to (A)uto and yet find the exposure to be wrong when I set the aperture to where I want it to be (with the shutter speed where it needs to be for filming).  Oddly, it's overexposed when I open the lens all the way up (indoors, where an ISO of even 400 looks fine, so it isn't as if it can't get down to a low enough ISO).  When I start stopping the lens down the exposure is fine.

Perhaps it's just because I'm so new to this camera, but do I not understand how this is supposed to work?  If I can't use Auto ISO then it will make life pretty difficult under the documentary conditions I am often filming (where the light changes frequently).  I'd much rather not put it in a creative zone since I want to have the shutter speed always at 1/50 (I'm shooting 24 fps) and mostly want 2.8 as my aperture (to blur the backgrounds).

Any advice would be helpful.

[RobertTheFat]

I don't quite get it (possibly because I'm a still photographer, not a videographer). If you're shooting at a given frame rate, can't you use any shutter speed that isn't too slow for the frame rate? IOW, couldn't you use 1/100 or 1/120 to address your overexposure problem? It wouldn't affect the background blur, which is entirely a consequence of the aperture setting. (It had better be, because motion blur is not what you want.)

[Kelleytoons]

Yeah, actually motion blur IS what you want in videography, but that's okay.

In trying to get a "film look" the rule is to set your shutter speed to twice your frame rate, so at 24fps I'm needing to shoot at 1/40 or 1/50.  No problem in bright light in that I can always add an ND filter and dial it down, but my issue is the basic auto ISO setting doesn't seem to be quite responding properly.

However, after doing more testing I'm coming to the conclusion it's just a matter of having to either meter separately or try and adjust the ND filter (assuming I'm using one) better.  It's made more difficult in that the LCD screen is hard to see in sunlight unless you crank it up and then it's hard to estimate exposure (again, most likely just need an external meter).  Lots of crap to think of when doing video you don't need to worry about when doing stills, so don't *you* worry about it.

(As an aside, I've also come to the conclusion that unless you are VERY good trying to do decent video and stills on the same shoot is an exercise in juggling I just can't manage -- too many eggs (and dials) to switch.  So I guess I'll either shoot video OR I'll go out and shoot stills, but never the two at the same (more or less) time.  No big deal, they are vastly different skills and trying to do both of them justice together is a lot to ask).