Dark Frame Subtraction, for noise reduction.
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Dark frame subtraction - Wikipedia, the free encyclopedia
DFS is incredibly annoying on long exposures because for every second of exposure there is another one added where the camera is busy working on DFS. I turn it off in my K10D and do noise reduction in post-processing... because when I'm taking a 5-7 minute exposure, I don't want to stand around for another 5-7 minutes after the shot until the camera is available again.
People also turn it off when they want to stack multiple shots of star trails together to get a continuous rotation of the stars in the sky. You need DFS off to eliminate gaps between consecutive shots.
I will upgrade from the K10D to the K5 in a few months, once the price starts coming down. The K5 is a huge advance over the K10D and I expect it will be a real pleasure to use. But I really really hope DFS can be turned off. It seems to me that is something that could be accomplished with some firmware programming.
Last edited by bats; 09-21-2010 at 06:11 PM.