Help- red, green, and blue spots in my pictures

[mtedelen]

Hey there,
Just wondering if anybody out there might have an answer for me. I was taking a couple pictures the other night and in a couple of my pictures there were a green, red, and blue spots in only a couple of the pictures that I took. I dont think it could have been a dirty sensor only because of how bright they were. It looked as though they were the size of a pixel or so. It could'nt have been from an Airplane becuase there were no streaks. I shoot with a 20D. Any ideas?

[Frans]

Those spots, the size of pixels, are know as hot spots. That means that a pixel has come on through random thermal noise. The way to over come this problem is by turning on the noise reduction in your camera. What is does, it allows you to take the picture as normal, then the camera closes the shutter for the same period as the shot you have just taken and subtracts the hot spots from the original image. The longer the shutter is open and the higher the ASA the more likely you are to get this problem.

Frans

[Photo-John]

There's also software that can remove them. I would just clone them out with Photoshop. That's the easiest way to deal with it. Raw Shooter - a Raw converter I use, has a noise reduction tool that finds these pixels and eliminates them from images. That's a really easy way to do it. If you have problem pixels - the same bad ones all the time, I believe some cameras have tools for masking those pixels. I'm not sure if the Canon digital SLRs do or not. But it should say in the manual.

[SmartWombat]

I think the 400D might be the first Canon that has that ability as part of the dust reduction system, there was mention of software spot removal in-camera.