I was shooting some exposure tests with a RED and I turned my tungsten reference light off to look at something on the camera. I noticed green roll bars crawling up the monitor, and quickly figured out that it was the rolling shutter interacting with the overhead cool white Ace Hardware fluorescents in the shop. The problem was completely eliminated by going to 1/40th/sec. on the camera shutter at 23.98 fps.
This was build 14. I understand build 15 will introduce shutter angle control in degrees, so it’s probably good to know that the equivalent to 1/40th is 217 degrees.
1/48th at 24 fps is right on the edge of the 60hz flicker-free window, so I habitually shoot with other cameras at 1/40th or 217 degrees just to avoid flicker issues with house power or odd discharge lights in the background. It looks to me like this practice might be mandatory with this camera. Any additional motion blur is minimal.
Notice how green the image is. Most other cameras (three chip CCD’s) don’t see the green spike in the average uncorrected hardware store fluorescent fixture. This camera sees it almost as strongly as film would. Very interesting.
Art Adams A native of Northern California, Art Adams spent ten years in LA--first at film school (Loyola Marymount) and then working in the film industry. He started out as a camera assistant on low budget features and worked his way into spots, music videos, features, sitcoms and episodic television shows. He transitioned from assistant to operator to DP by the time he returned to the San Francisco Bay Area in 1993.