I have a problem. That problem is sensor dust. The Canon EOS 20D is a wonderful camera, but it is also a dust magnet. After owning the camera for about a month I noticed large spots on my images. After cleaning my lens I did some research and found that the sensor attracts dust and the dust shows up on the images when you have the lens stopped down. I found a great way to test this was to take a photo of something bright (the sky) with the lens stopped down all the way, when I did this it was pretty painful to see how much dust was on there. I looked around for a solution and I saw some things that seemed somewhat sketchy to try and also saw the option of taking my camera in to have it serviced which seemed like a waste of money.
I was browsing around on the Adorama website I found some products made by a company called Visible Dust. These brushes, swabs and solutions are made specifically for cleaning CMOS sensors and the company actually started out making products for cleaning lab optics. After reading some 3rd party reviews of their products I ordered the 1.6x brush set and patiently awaited its arrival.
When it came I opened up my 20D, put it on sensor cleaning mode and cleaned the sensor. I turned off the camera, put the lens on and took some pictures stopped down, about 90% of the dust was gone, but there were now a few small streaks where what must have been an oily goo had been smeared by the brushes. So that night I ordered the sensor clean kit, that comes with sterile poly swabs and a non-alcohol cleaning solution. The kit came today and I opened it up and cleaned my sensor. I now have 0 spots on my sensor. Yay!