A Guide For The Perplexed Pixel
We get all sorts of service calls here for repairs and maintenance to digital cameras. One of the most frequent worries is material contaminating the sensor and showing up in the image. Here is a little guide to understanding what you see and what to do about it.
1. Vague grey blobs on an even grey ground are dust particles on the sensor - they shade the surface and thus it is darker, with a fuzzy outline. You may see a crescent-shaped item - likely a hair on the sensor.
You can clean the sensor yourself with a number of commercial brushes and swabs, but in the hands of the ham-fisted, this can carry a real danger of scratching the delicate surface. Ruin the sensor and you might as well buy a new camera...
Better plan is to let the technicians here at CE clean it for you. They do not ruin sensors, and the cost and time required for this service is not excessive. $44 for a small mirrorless camera, $55 for an APSC sensor, and $77 for a full frame DSLR.
3. We were asked how to get rid of this irregular-shaped mark on the image. If it is just one-off I would suggest Photoshopping it out with the clone tool. If you get a have a lot of these recurring, get yourself a Mossberg .410 and a box of No.7 shells.