CMOS sensor stain.

[cool9]

I read (Bob Atkins) how to take a photo to check your CMOS sensor for dust (set to f22 and exposure compensation=+1). I found I have dust and I found 2 small stains. No stains are visible on the sensor to the naked eye. What are these stains? Is the sensor permanently damaged? (I took some sports photos on Friday and they came out well. Today I took some closeup stills and the stain is just slightly noticeable.) Camera is 20D which I bought secondhand last year.


Stain(s) lower left:

[Colin]

You could try to clean the sensor with a kit, or see if you can blow out anything invisible, or you could send it into Canon, and they can give you a cost on whatever it is and you can decide if it's worth it to not have to use the stamp/clone tool. It does, though, look like the sensor is pretty dirty.

[cool9]

I cleaned it and it's OK. Took a few tries with wet/dry swabs.