When dirt and debris sneak into your camera body, they have a negative impact on pictures. Anyone who has seen dark spots in blue skies, for instance, or fuzzy blotches at the edges of the frame is likely plagued by a dirty sensor. Of course, sensors can be cleaned to eliminate such problematic dust spots, but an ounce of prevention is worth a pound of cure. So to avoid spots and marks on your photos, try keeping the dust particles out of the camera in the first place. Here are seven techniques to help keep dust outside the camera so it won’t cause spots that ruin your pictures.
1. Be careful when changing lenses. Namely, minimize lens changes outdoors, avoiding lens changes altogether in dusty, windy, dirty conditions. How can you work around lens changes? Leave the house with a zoom lens on, for instance, rather than switching from wide prime to telephoto while on location.
2. When you do change lenses, work quickly and efficiently in order to ensure the lens is off the body for a minimal amount of time. Have the lens to be attached—or at least a body cap to cover the camera’s opening—ready and waiting. Try to keep the camera open for as brief a moment as possible to improve the odds of keeping the sensor clean.
3. Before changing lenses, turn off the camera. Ever see how static electricity attracts dust to a CRT display, like an old-school TV? The same principle is at work with your camera sensor. The electrified sensor effectively draws proximal dust toward its surface. So instead, turn off the camera before removing the lens so that static charge dissipates.
4. Orient the camera body so that its opening points toward the ground while the lens is off. If you think of the open camera body as a cup, with the opening of that cup facing up, dirt and debris in the air naturally float down into it. With the opening facing down, however, that dust has to work a lot harder to find its way into the camera. Open cameras facing down to make it less likely airborne contaminants will settle in the open camera body.
5. Keep lenses capped when not in use. This is especially true of the rear element, which could collect dirt and then transfer it into the body when it’s attached. I’ve known photographers who leave lenses uncapped for days or weeks on end. This is practically begging for dirty sensors! So as soon as you remove a lens, cap that rear element.
6. Use a blower regularly. I use a Giottos Rocket air blaster every time I change lenses. I aerate the inside of the camera body with a few blasts, and the element on the rear of the lens as well. And I never use compressed air for these purposes because it could damage the sensor.