Dslr Dust - What I Do

[marktomaras]

Dust is a fact of life when changing lenses on a digital camera.

I have found the least invasive way to clean the sensor is with the special brush made by a canadian firm called Visible Dust. The brush is not cheap at about 100USD, but it is way more effective than pads, stickers, air, liquids, etc, not to mention way safer on the camera. Visible dust has videos on the web site and pretty good directions.

I have been shooting with DSLR cameras for 3 years now, and have owned 3 different models of camera. I have tried many methods, some good, some bad, some even dangerous! I once sprayed air from an air compressor to clean the chip, which was a pretty good method, but then the air compressor sprayed out a bunch of water! it was condencation in the tank and I was very lucky. I had moved the hose away from the sensor just seconds before so the water just hit the outside of the camera. I am writing this to share my most successful method of sensor cleaning because I think many people do not know the best and most careful method.

Canon did a small repair on my camera and they cleaned the sensor here in BKK free of charge. I had cleaned the sensor just before going in for service. when i got the camera back, the sensor looked terrible! They told me they use a sticker as well as air from a can to spray off the sensor. This is a terrible method. Canned air contains lubricants in the way of very small bits of moisture. I could literally see the effects of the liquid on my sensor when I "took a photo, or a dust map image of the sensor"

Make a "dust map image" of your camera's sensor. Here's how:

Set the apeture to f/16

set the iso to 400 (this will let you work in a normally lit interior room)

set the shuter quite slow, you'll need about 1 second or so at ISO400 in a normally lit room at f/16

the shutter doesnt matter, slow is okay, even beneficial.

use manual focus and set focus at infinity.

take a photo of an evenly lit plain white surface. A sheet of white A4 paper, a plain wall. just be sure there is little or no detail on the surface. Get the camera just about 10cm from the surface. because you are set at focus infinity, the details become totally blurred out. Becuase the shutter is slow, if you hand hold the camera, the scene blurs even more. What you end up with is a photo of all the little particles on your sensor.

download the image, take the color away (easier to work with), add a little contrast, and you'll have a great picture of the dust on your sensor.

Zoom in to 100% view. Don't freak out, as you may be quite shocked at all the dust.

Use the sensor brush in the manner described by the manufacturer.

Then make another dust image. I usually can get the sensor cleanded in one or two attempts.

You'll never really be able to get all of the dust, but if you get the lion's share including the big stuff, that is good enough.

I included a link to a zip file with 2 images. one is the first dust map I made on my dirty sensor. i circled all the dust in red. The second image is a dust photo after 2 cleanings. I look at these briefly at 100%, but zoom out to 50% for a more pratical view of what is there as I scroll around the image.

http://marktomaras.com/dust/

at the link, download the dust.zip for the 2 images i provided.

Good luck! Keep your sensor clean!

- Mark

[astral]

Thanks for that useful information.

[Crossy]

I'll second the use of the Visible Dust series of brushes, very effective.

A couple of points:-

Shoot the plain wall / paper / sky as suggested, if you have Photoshop apply the 'auto-levels' adjustment, the dust will jump out at you.

When you look at your screen the dust will be in a position flipped about a horzontal axis when you look into the lens aperture. What I mean is, if the dust appears at the top right of your image it will actually be at the bottom right of the sensor as you look into the camera.

[marktomaras]

very true and good point. if you are using photoshop to view the dust image, do a 180 degree rotate command so you will be looking at the sensor as you would be looking in the camera's chamber.

As for the auto levels command, it's true that it makes the dust jump right out at you, but the image becomes very high key and the smaller, more subtle dust sometimes becomes invisible with this command. It is useful to toggle it then, so do the auto levels, look, then click undo, and have a look.

by the way, for anyone interested, i have an extra brush from visible dust. it is the 1.3x chip size brush. I bought it for a camera that I no longer own. It is in perfect condition...