Digital Photography Tutorials | Image Sensor Cleaning

Manufacturer's Position

Manufacturers of Digital SLR cameras generally advise purchasers not to touch the surface of the CCD image sensor. Some users express the view that this warning is most likely due to a policy adopted by camera makers in the interests of preventing damage to the low pass filter surface and internal parts of the camera by unskilled users and to avoid liability problems.

Some makers advise that cleaning of the sensor should only be carried out by qualified service personnel. Such service, which potentially might need to be done frequently, is usually costly.

A possible problem with having the sensor cleaned professionally is that mobile contaminants which may still be present within the camera body, could find their way onto the sensor during shipping or transit to and from the service center.

Do it yourself?

Users can, if reasonably nimble fingered and prepared to take some time and care, accomplish this task themselves.

Disclaimer

We have to state at this point that this method is not an official procedure with approval from any camera manufacturer. It is offered without any warranty and no responsibility or liability for damage to equipment or persons will be accepted by this website administration or its author. If used, any risk or responsibility must be accepted by the user.

It should also be mentioned that using any method not recommended by the camera maker may void your manufacturer warranty.

If you feel uncomfortable or have any reservations about this method, then don't use it - have your camera sensor professionally cleaned.

If you do feel comfortable about cleaning the sensor yourself then the method described below might be helpful.

Requirements

Good light - strong daylight is suitable.

Good eyesight or appropriate glasses are also required as some dust particles can be extremely small.

A clean soft lens brush or clean soft artists brush.

A cleaning tool which can be made from a plastic kitchen spatula carefully cut to the width of the camera image sensor and wrapped with a folded 'Prep Swab' or 'PecPad'. The folded swab can be held in place with a rubber band. Be careful not to tear the swab material thus exposing the spatula edge which could come into contact with the glass surface of the sensor. The swabs are lint free wipes impregnated with alcohol. Try your local family drug store for the swabs.

Access to the sensor low pass filter surface is needed. Activating the mirror lockup function which can be found in the camera menu will achieve this.

Caution!

During the time that the mirror is up, take particular care that the camera power switch is not accidently bumped off as the mirror will instantly unlock and impact against any cleaning implements or fingers which are still present inside the body of the camera and damage might occur.

Types of Contamination

It is useful to consider the different types of contamination. Dry loose particles which statically adhere to the surface may simply need to be gently wiped away with a very clean, soft lens brush or artists brush. Particles which are 'welded' to the surface - this can happen under humid conditions - may be stuck in such a way that they cannot be displaced by a dry brush and will need to be wiped off with the wet cleaning tool mentioned above.

Method

Before opening the camera or attempting to do any cleaning, take some test shots. A pure white screen on your computer monitor or a shot of a clear sky will produce suitable flat images.

To obtain a white screen on your computer, set your web browser to display the 'about blank' page.

Zoom in and set focus for a diffuse white field in your viewfinder.

Download the images to your PC and observe where any spots or blobs are located. This will help to locate them on the sensor surface when you open the camera. Keep in mind that when looking at the face of the camera sensor, you will see a mirror image of what you saw on the test image. It will be reversed horizontally as well as inverted. This means that a spot which was visible at the top right of the picture on the test image will be present at the bottom left on the sensor. This happens because camera lenses always produce images at the focal plane which are reversed and inverted.

Prepare a suitable clean work space where good light is available and have your brush and cleaning tool ready.

Remove the lens and fit its protective lens cap and rear cover. Avoid leaving the camera body with its lens opening facing upwards as more contaminants could fall in.

Activate the mirror lockup function. Remember! Be very careful not to bump the camera power switch off during the rest of the cleaning operation.

Study the sensor surface. Tilt the camera a little in all directions to catch the light on all parts of the surface. If you can see any foreign matter - it may be in the form of extremely tiny specks of dust - try the soft brush first. Wipe the brush in one direction dragging the offending matter off the end of the surface.

Remember that the surface of the low pass filter is glass. Glass can be scratched. So it is important that no hard objects or grit are wiped over the face of the glass.

Resist the temptation to blow into the camera body as breath is moist, may contain food fragments and could cause particles to adhere more stubbornly or add more to the sensor. Be wary also of pressure pack cans of air or gas as these can contain traces of moisture or oils.

If you think the contaminants have been removed, making sure that nothing is still within the camera body, unlock the mirror and replace the lens. Shoot another good test image and inspect it on your PC monitor.

If there are still contaminants present, start the procedure again.

If there appear to be stubborn particles which can't be removed with the soft brush, then it will be necessary to use the wet wiping tool.

The technique for using this is to make one wipe across the face of the sensor from one side to the other in one direction. You may find that three sides of the sensor are recessed but one side has a land which is flush with the sensor surface. If so, wipe towards this land. Having made one wipe, study the surface again to see if the contaminants have been removed. If particles are still present, fold a new swab over the end of the spatula tool and make another wipe. Repeat the process as required with a new swab each time until the surface looks clean. Take care not to touch the part of the swab which will contact the sensor as body oils could be deposited onto the surface and cause smear.

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