|RedCam CentralSite Admin
Joined: 14 Dec 2006
Location: Los Angeles
|Posted: Sun May 24, 2009 7:38 pm Post subject: Exposure 101
Jim Jannard recently posted these notes regarding setting proper exposure:
"This topic has been covered before. Many of you know all this stuff. But there are new RED shooters everyday and some that are still struggling with exposure. Buried in this post is a question for the community. We'd love your opinion.
There is plenty of DR in a RED ONE to make great images... many have proven that. But the range is limited enough that you can easily miss the window if you are not careful. Let's recap a very simplistic starting point for exposure to keep you out of trouble.
Under-exposure leads to noise. Over-exposure leads to clipped highlights. So... don't do either, unless you really want to.
1. Make sure your monitor/LCD's brightness is set correctly. The RED LCD's need 4 or 5 clicks down from full bright in most circumstances. If set too bright... it seduces you to stop down and under-expose.
2. ETTR. Expose to the right. Just under the point of clipping. That keeps you away from noise in the shadows and keeps detail in the highlights. In a dark scene you may choose to allow some specular highlights clip. See False Color or Zebras below.
Use your tools.
Quickly set approximate exposure by looking at the LCD.
Check the color bar next to the histogram (which corresponds to False Color colors and originates from RAW). Turn out the top red box. That is the equivalent to clipped. Don't worry about the orange, yellow or other colors... they are probably supposed to be lit.
The Stop Lights next to the color bar are from the RGB path! Don't let them fool you. Sometimes they are on and you still have detail in the highlights. We are likely to change this in a future build to represent RAW and not the RGB path. Thoughts?
Use False Color. Red means clipped and purple means super dead. I set my top left LCD button to False Color in User Prefs. If it (something in the scene) is red... it is dead (clipped). There are time when you might be OK with that, but False Color tells you exactly what is clipped. You choose instead of guess.
Use Zebras. They will tell you exactly which highlights are blowing (you need to know)... you can also set them for the shadows, they "buzz alert" when you are likely to encounter a lot of noise. You can set the top and bottom limits to each of them.
If anyone cares to add... please do."
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