Fighting with computers

My old analog camera is also giving me trouble. The symptom was that many pictures had just a small fraction of the total field. This can happen when shooting with flash if the sync speed is not correct (flash fires when shutter is half-open only). However this time I was shooting outdoors without a flash. After a few iterations with Google led my to a photo on Wikipedia with exactly the same type of residue I've found on my camera. A few more searches led me this article that explains the causes of the problem and a possible fix. Aging and heat turn a piece of foam inside the camera guts into an oily tar that ruins the shutter operation. Did you think you can keep on using your old camera, maybe not if it as a twenty years old Canon EOS.

One of the bad things about DSLR (aka Digital Reflex) cameras is the tendency to get dust in the image sensor (as these cameras use removable lenses). Whether it is just dust or pollen it may eventually be shown in your photos (like the spot I show on the right: it is just blue sky). For not so big spots, they may go easily undetected. If you want to check for dust in the sensor the simplest way seems to take a photo of the blue sky with the smallest aperture possible on your lens (F22 in my case). Detecting the problem only serves to make you nervous, but fear not, it can be fixed. There are different ideas and people who would talk for or against any of them. I do not feel comfortable risking my camera sensor without reading quite a lot before doing one thing or another. Apparently there are several ideas that can help: Air blower. Dry dust removers. Wet dust removers. Send the camera to the manufacturer for a professional cleaning of the sensor. The first three is something you can