okay i tryed takeing a HDR and there was dust anf messed my pic up, i blew out most of it but there still is on spec that i cant get out any help, i have a d70, i mirror locked and checked the mirror and nothing on the sensor
If you definately can't see it (try using a maginfier) then it could be a pixel failure.
However it's more than likely to be a dust speck, I'd get hold of 20x loupe and try again. It could easily be smaller than most eyes can detect unaided.
PopPicker outmanouvered me again [is that how you spell outmanouver?] He/she is right, there is no way you can check visually if there is dust or whatever on the chip. Take a shot, if any problems with dust, it will show on the image. muck on the mirror will have no effect.
philip. www.philipweirphotography.com
I had a similar (possibly exact) same problem. A giant smudge on all my pictures. I went to a "repair shop" and the guy cleaned the sensor in about 30 minutes for $30.