Sensor Cleaning Mythbusting (Part 1)

If I should name the one single most annoying nuisance of photography with a digital SLR camera, it is dust on the sensor. No doubt, no hesitation. Dust on the sensor is a problem (and to make a long story short, all the cleaning techniques I've tried so far are crap), and it annoys me to no end that it is completely unavoidable to go through this repeatedly.

How do you find out if you have dust on your sensor? You take a photo, and in an area that should be a plain blue sky or something, there's suddenly a slightly darker spot, very often round, with a soft border. Not a major problem because this can be removed easily with programs like Lightroom or Picasa (version 3, of course).

The dust will become more visible as you stop down the lens. Some lenses allow a maximum aperture of f/36, and the dust that is a slightly dark spot at f/11 will become a quite massive black chunk. Again, not a major problem because you shouldn't stop down that much anyway (because of the lack of sharpness caused by diffraction).

First: you shouldn't test your sensor for dust unless you have to, and the dust really cripples your photos. If you don't think you have a dust problem, don't start looking for it - it'll be there and cause you sorrow. :-) If you do have a dust problem and need to verify it you can test your sensor very easily: set a large aperture (in other words: tiny opening, like f/22 or something), set the focus to infinite, move close to a white area like a wall, or a piece of paper, and release the shutter. Then, inspect the photo.

So, as time goes by, the sensor will attract more and more dust. It just happens. No matter how fast you are changing your lenses - you open the mirror chamber of the camera, and you get dust in. As the mirror moves rapidly up and down to allow the light to reach the sensor, it will move the dust around, and some of it will settle on your sensor. And then some day, you spend half of the time for your normal post processing, and the other half for removing dust spots from your photos. Thats the point where you probably want to clean the sensor.

I'll cover some of the cleaning techniques and describe my experiences in the following post(s).