My 10d was sent to Canon Factory Service for repair because it's got burnt pixels. Before I sent it there, I tried many times to clean the image sensor with q-tip wrapped with pec-pads with cleaning liquids from Canon. But still didn't solve the problem. The problem I had was that there is always black circle showed on the picture everytime I took a shot of clear blue sky. I just spoke with Canon customer service earlier today (9/22), he said that they fixed my camera. When I asked how, he just said that they cleaned the cmos filter. But then again, he told me that the problem will likely to come back as the filter gets dirty. Now, I really wonder, did they really fix that problem. I haven't got my camera back, it'll get here on Thursday (9/25), so I can't test it and see it for myself.
My question here,
What is cmos filter? Is that the same with image sensor which I tried to clean many times?
How am I supposed to change lens? Do I need to lock the mirror before I detach the lens as if I wanted to clean the image sensor?
I have sample of the picture. I crop this picture. Now if you take a look at the middle of the picture, it shows very faded black circle. Does it look dust problem to you?
