I took this star trails photo: http://imgur.com/kaHqZnA (go ahead and enlarge it) and it came up with a bunch of red and green noise. I've never had any problems like this before, just on my new Canon t4i. I've shot star trails for this long (long exposure, about 2-3 hours, ISO 100, large aperture) on my old Nikon D5100 and never got any sort of noise. I shoot regularly on this camera and even do other long exposures for shorter amounts of time but never get and noise.No, there was no big light behind me or anything, all light was natural. I've shot in the middle of the woods and had the same problem. Any suggestions?
Added (1). Correction: never get any noise*
См. статью: Why did my long exposure (star trails) photo come up with all of this noise?