Sony F770--Long exposure time=white spots on my image??greenspun.com : LUSENET : Imaging Resource Discussion : One Thread |
When I take a picture with an exposure time of 1 sec or more I get white speckles on the image. Now to test if it was actually the ccd... The lens cap was put on and a picture was taken of "just black".(4 sec exp) Now it didn't matter what photo quality was set to or what resolution was used, the speckles still remained the same. The only setting that made a difference was the ISO setting. The spots were much more evident with the ISO at 400 than they were at the 50 setting. Did I buy a defective camera?? The specks are not visible on the LCD screen. However, they are EXTREMELY visible when using a 25" TV to preview images, and are visible but not to the same extent, using a 15" computer monitor.
-- Walter Mecleary (waltermecleary@aol.com), March 31, 2000
white is unusual... are you taking it in black and white? the symptom you are describing seems to be related to ccd noise... the ccd has it's limitations, and usually occurs in the consumer digital camras due to cheaper ccds.....it's evident in long time exposures and more if the ISO is increased (ISO levels are increased by multiplying the signals that are coming from the ccd, therefore it would just increase the chances of more noise) ... usually there are small spots of about a couple of pixels and can be removed by a decent paint program...
-- Keat Lim (keatlim@my-deja.com), March 31, 2000.