How To Know Your Sensor is Dirty

Cleanup time: You can send the camera out to have the sensor cleaned if you don't mind the expense and time, but for most people the only long-term strategy is to learn to clean it yourself.

DIY: A squeeze bulb that blows air on the sensor is not very effective, especially for older spots that can become almost glued on. Heavier-duty cleaning is done with a brush or solvent-and-swab products. See Dust Busters! to learn more.Use a freshly-charged battery and don't touch the on-off switch or bump the card door open while cleaning.

How to Spot Sensor Dust

Sensor dust spots are much more obvious at small apertures, and against clean areas such as a sky. In images shot with medium apertures they are larger and lighter gray. With wide enough apertures many may not show at all. They are also less obvious in very bright or very dark areas. Here is a portion of a sky shot with a dirty sensor.

Diane Miller is a widely-exhibited freelance photographer who lives north of San Francisco, in the Wine Country, and specializes in fine-art nature photography. Her work, which can be found on her web site, www.DianeDMiller.com, has been published and exhibited throughout the Pacific Northwest. Many of her images are represented for stock by www.MonsoonImages.com.