Advanced (wet) sensor cleaning

Dry cleaning is often effective for the majority of CMOS dust spots. However, over time, you’ll likely encounter some spots that just don’t go away, that have seemingly become stuck to your sensor. Additionally, because the sensor is an electrically charged component, it may easily re-attract dust particles that have been blown or brushed aside during a dry cleaning process. You will undoubtedly come to a point where it is necessary to clean your sensor by wiping it with a chemical solvent — a wet solution that can loosen virtually any particle.

You can always choose to have your camera cleaned professionally by Canon or a Canon-qualified technician. The advantage to doing so is that you take on no liability for accidentally damaging the camera, and they always clean many other components in the camera as well that you most likely do not have the tools or skills to address. Even if you do clean your own sensor using a method that physically touches it, I still recommend having your camera professionally cleaned annually if you use it frequently.

A number of wet method products are available, each with pros and cons. A few use alcohol as the solvent, but most use methanol as the key ingredient to rid the sensor of dust. You simply wipe the sensor gently with the chemical-saturated swab, and allow it to dry (which is nearly instantaneous). Most sensor-cleaning kits come with various sizes of swabs to fit various sizes of sensors. Many also include a carbon dioxide (CO2) cartridge and device to safely blow clean your sensor with a very controllable stream of gas. (Note that this differs from the canned air that you should never use, as I mentioned earlier.)

One of the best resources I’ve found for information on sensor cleaning is Fargo Enterprises, which sells products as well as provides a tremendous amount of information about sensor cleaning — wet and dry — and the many types of products available on their Web site ( They have researched numerous Web sites, camera manufacturers, and other sources to provide a comprehensive one-stop plethora of information. If you plan to do your own sensor cleaning — wet or dry — I suggest you consult their site to be completely informed.

According to Fargo Enterprises, the most commonly used sensor-cleaning product is Sensor Swab Eclipse, from Photographic Solutions Inc. ( — the only company to unconditionally guarantee that you will not harm your sensor or they will pay for your camera repairs. You use the product with Eclipse, a methanol-based cleaning solution you put onto the swabs (see 10-8).

Photographic Solutions Inc. offers a kit containing several Sensor Swabs, Eclipse cleaning solution, and a set of Pec Pads for cleaning lenses and other components. (Pec Pads are not designed for sensors.) Note that you will need to use a swab that is sized correctly for your camera's sensor.

To clean your sensor with this product (which is similar to others, but be sure to read any specific instructions with the product you buy), you first get rid of any loose dust particles with a bulb blower (or CO2 blower), and then disperse a few drops of methanol from the supplied bottle onto a swab and use it to wipe the sensor (or, technically, the low-pass filter in front of the sensor, as I previously discussed). You wipe once in each direction, back and forth (horizontally). After wiping the sensor, you will want to check to see how effective your job has been by testing a few shots for any remaining particles. You can then repeat the process, if necessary, but frequently one time is highly effective.

Beware of one thing regarding the usage of methanol: It is highly flammable and cannot be shipped by air. If you order it via the Web, it will have to be shipped by ground. Furthermore, because it is considered a hazardous/flammable material and a solvent, you cannot take it with you on a plane in carry-on or checked baggage.


Canon, like a number of other camera manufacturers, does not recommend or endorse the use of any cleaning method that physically touches the sensor — dry or wet — and, in theory, doing so voids the warranty on your camera. The only sensor-cleaning method Canon supports is using the handheld bulb blower. Beyond that they recommend having the camera serviced by qualified Canon technicians. Still, many photographers use the wet method to clean their sensors, and at least one of the sensor-cleaning products (Photographic Solutions Inc.) actually comes with a guarantee that you will not hurt your camera when using their product as instructed.

Category: Camera care

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