CCD Dust Removal

The Camera Sensor

• It is important to note that if you aren't careful with these procedures, you can damage your digital camera sensor. You're not actually cleaning the sensor itself, but rather a low pass filter that is mounted in front of the sensor. This filter is referred to as an anti-aliasing or IR block filter. In the early days of digital cameras, manufacturers warned against users cleaning the sensors themselves, suggesting that the cameras be returned to repair facilities for cleaning. But there are now a number of tools offered on the market for keeping sensors clean.

Dry and Wet Cleaning Methods

• There are two methods of sensor cleaning: dry and wet. For dry cleaning, a small bulb blower or a brush designed for removing small particles from sensor filters is used. You should never use a swab such as a Q-Tip, which is likely to transport in more dust and lint than you'll remove from your sensor. For the wet method, specially designed swabs or pads are lightly moistened with a methanol solution, and then swept over the CCD. The idea of the methanol is to get the dust stuck to the swab or pad, and not just have it moved around the surface of the sensor filter. Avoid using compressed air (CO2 charged canisters), small hobby air compressors, such as those used with airbrushes, or foot pumps. These units can blow liquids, oils or dirt onto the CCD.

Products Available for Sensor Cleaning

• Several dry and blower brushes are produced specifically for cleaning cameras. The Sensor Brush is used by sweeping across the sensor filter, then removing and blowing the dust off of the brush with compressed air. Commercially produced swabs include Sensor Wand and Sensor Swipe. Many swab producers recommend the Eclipse methanol solution made by Photographic Solutions Inc. If you want to go the home-brewed route for a swab, you can wrap a small piece of Pec*Pad material around a stiff but flexible holder such as a small Rubbermaid spatula or a shaped tongue depressor.

Setting Up for CCD Dust Removal

• Arrange a clean work area, such as a kitchen that has been recently wiped down. Get a headlamp, or mount a high-intensity desk lamp where you can easily shine it into the interior of the camera. You can mount the camera on a tripod to make it easier to have both hands free. Follow the manufacturer's directions for locking up the mirror. This usually involves using the AC adapter to avoid having the camera batteries fail midway through your cleaning procedure, bringing the mirror down onto the brush or swab and thoroughly messing up your camera.

CCD Cleaning Procedures

• The first line of dust defense is to use a blower bulb to dislodge any dust that is just sitting on the surface of the filter. Hold the camera with the lens mount pointing down so that any dislodged dust will fall out of the camera. If you do this regularly, you might well keep dust off of the sensor without ever needing to resort to swabs and liquids. The second level of cleaning is to use a dry brush, such as the Sensor Brush, to remove dust particles that aren't really stuck to the filter but can't be dislodged with the blower bulb.

  If you find that you need to move to the wet method, lightly moisten a swab or Pec*Pad. A swab or pad that is too wet may leave streaks on the sensor filter. Clean in one direction only; don't scrub because you'll just be moving the dust around the sensor area. Use very light pressure as you sweep the swab across the sensor.

  Most sensors have a rim or sidewall around the sensor. Tuck your swab into the upper left-hand corner of the rim, and go straight across to the upper right-hand corner. Lift the swab, but don't turn it. Put it back down against the rim of the lower right-hand corner, and move it back to the lower left-hand corner. Pick up the swab off of the sensor filter surface and remove it. Be careful not to contaminate the brush or pads with oil from your fingers, as this can be easily transferred to the sensor filter.

  If you have a stubborn piece of dirt that will not come off with these methods, it's time to send the camera to a professional. You don't want to damage the sensor filter--replacing one requires disassembling the entire camera, and that gets expensive.