5DMkII Video Exposure Trick

[AndrewCCM]

Something I was playing around with...This may or may not help anyone, but thought I'd post.

As everyone is starting to realize, exposure control (or lack there of) with the video feature on the 5DMkII can be problematic. In particular, with depth of field. For instance, out doors in bright light the camera will automatically pump the aperture up to very small f-stops.. Well let's say you want to have a shallow depth of field outside... The only solution that I was able to figure out was to stack ND (Neutral Density) filters to force the camera to open up.

Well.. Here is something interesting (at least to me). The order in which the camera seems to determine exposure is... 1st set the Aperture, 2nd Shutter, and 3rd ISO. When it needs to make adjustments after the initial exposure, it reverses the order.

So here's the trick. Cover your lens with your hand, lock your exposure... This will more than likely make your exposure the shallowest FStop available, crank up the ISO and lower the shutter speed. Well as long as you have your exposure locked everything will remain like that even when you point it at your subject outside. From this point, you can then press the * button and it will start readjusting the exposure for the current scene... BUT IN REVERSE ORDER So.. Basically, it will drop your ISO levels dramatically, start raising your shutter speed until it gets the correct exposure. Your Aperture will not changeunless it cannot compensate with ISO and shutter for the conditions. I have found that in most situations this is not a problem. So to sum up... you have tricked the camera into opening the aperture and make other adjustments for the exposure. Kludgy...but it works. I would guess you could come up with various ways to have it set various apertures by toying around with the amount of light in the initial exposure.

One thing I haven't tested is just the opposite. For instance, in a dark indoor scene where you need more DOF, you might point it at a lamp or shine a flashlight into the lens to make it stomp down. Then use the same trick to make other adjustments.

Anyway.. Just thought this was interesting enough to pass along.

Have a good afternoon.

[Supermanny]

Very cool Andrew. Thanks for sharing.

[ldelacruz]

Thanks for the tip.

[luis_relampago]

That is a very good tip Andrew.

[crazeazn]

another protip by TPF!

[ldelacruz]

Is there anyway to set it to continous focus? Kinda like AI Servo. I thought mine was doing this the other day but it may have been the IS motor I was hearing.

[AndrewCCM]

It will if you hold down AF-ON.. However, it is contrast detection and it is very slow. So in reality.. Not really. Manual focus is really the only way to be effective.