Sunday, April 4, 2010

Getting Perfect Exposure



In this week's episode, I look at some cool things you can do with a gray card and/or the palm of your hand. Not only that, but I learned about an undocumented feature on Canon HD camcorders. When you don't have enough light, the camera will warn you accordingly. Since some of these cameras allow you to turn off Auto Gain Control, this feature is invaluable to getting the best picture possible.

5 comments:

Chris said...

How does this relate to white balance? Ive always gotten confused on what really adjusts the exposure properly and what makes the colors and lighting look true. Or is that the distinction? White balance for colors and exposure for light.....

Scott Eggleston said...

You're exactly right, Chris. White balance tells the camera what "white" looks like. That is why when you white balance on one color temperature (like incandescent bulbs), sunlight will look blue. While balance on sunlight and indoor bulbs will look very orange. Interestingly, you can white balance on the gray card just as well as any white object.

Exposure deals with how much light is getting to the sensor, whether via lighting you provide or pushed levels using gain. It seems to be a camcorder thing as higher end cameras only use the iris (or aperture) and shutter speed to control light. I'm not positive, but I'm pretty sure "exposure" is just the camera using both of these simultaneously to add light to the image.

DIYFilmSchool said...

Another great video tutorial.

You know, I never understood why DPs walk around gauging light sources using a balled up fist. I understand it's to assess shadows and fall-off, but a face has different ridges and depth than a fist. Can you comment on that at all?

Scott Eggleston said...

I really can't as I've never tried the "balled-up fist" method. Have you seen my video using John Alton's "test light"? That's the way I would go.

DIYFilmSchool.net said...

I haven't. I'm off to check it out now. :)