there are other pixels coming through bright enough to register as hot because of thermal noise. note that the test program is using a pretty liberal definition of hot. thermal noise can be pretty high on some sensors. look at the actual TIFF image and see just how bright they are. it takes some extra work, but you can detect some hot pixels against a dark background and filter them out even without dark field subtraction. there are not many things in nature of a color that happens to trigger only one pixel and no adjacent ones.
Herb.... ----- Original Message ----- From: "Rob Brigham" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Monday, March 15, 2004 8:05 PM Subject: RE: *ist D Pixel Comparison Test > But surely if it is a hot pixel then it will always be hot at that > exposure? If it was only hot for one of the two frames then it must > have been an error in the data rather than a stuck hot pixel. It is my > understanding that the dark frame exposure is the same 'shutter' time as > the main shot, so if it is truly hot it should be there too.
