Over time, cameras get dirt, lint, or other foreign materials on the sensor. You may be noticing this as spots on the pictures when printed or shown on a large screen. One way to do a quick check is to try a few test shots with the camera. Use a short or macro fixed lens, or set your zoom on the lowest zoom position, in manual mode and set the aperture to f/16 or higher. Also set the lens to the closest distance setting, regardless of zoom, and out of focus. Take some exposures, out of focus, on the sky, or on a white surface or wall. On a computer screen or large print you may see some spots or specks that are on all exposures at the same location. This could indicate the need for sensor cleaning (obviously ensure your lens is clean before this test).
We do stock what you need to clean your sensor yourself from industry leaders such as VisibleDust and Photographic Solutions. If you prefer, one of our technicians in our Repair Department can clean it for you. Please call for a quote and estimated turn-around time (650) 327-8996.