Best way to check for sensor dust-help needed

[photopaque]

I was just wondering what is the best way to check my 350D for sensor dust?Sorry if this has been asked before.

[tim]

Have a look at page 5 of this site, it's what I use to check my sensor and clean off any dust. It's probably the oldest and best known cleaning method around, and while it's not without risk, the risk is very small if you follow the instructions closely.

http://www.pbase.com/copperhill/ccd_cleaning

[primoz]

It's just my opinion but as long as you don't have problems with visible dust on your photos then it's useless to check. If it doesn't bother you, then why to be in bad mood when you will find there's dust there.

[photopaque]

What i mean is do i take a 20 sec exposure of a white card...........is that the best way to view results?I dont appear to have any probs at the mo but i want to just be able to check on a regular basis.Thanks.

[dhbailey]

To check for dust, I go outside and shoot a picture of the blue sky or of an evenly light overcast.

The blue sky works like a charm, I find.

[grandad35]

Look at the first reply to:

http://photography-on-the.net/forum/showthread.php?t=63350

[hmhm]

You don't need a "sky" nearby to check for dust.

If it's more convenient for you to do this indoors (it certainly is for me, since that's where I'm going to be cleaning it if I need to), then all you need is some uniform surface, like a white painted wall or ceiling or something. In a pinch, a sheet of paper is fine too.

Turn off the flash, turn off auto-focus, stop the lens down to f/22, and set the room lights to ensure that the camera will pick an exposure of at least a few seconds. Press the shutter button, and sort of "sway" the camera around to blur out any detail in the wall's surface. The dust is on the sensor, of course, and so moves with the camera. You'll end up with a nice picture of the dust.

If the question is "does my sensor have dust", the answer is always "yes". The proper question is "is there enough dust that it will be visible on my images and cloning out the spots in Photoshop will be too much effort?" From this perspective, consider that dust spots are more visible as you stop down the lens. If you're an f/2.8 sports shooter, doing this dust test at f/22 isn't that useful to you, as it will show you all sorts of dust that will never appear in your real shots. So do this test at f/22 for curiousity, but also do the test at the smallest aperture (largest "f-number") which you use regularly (e.g. f/16 or f/8, if you never get closer to f/22 than that).
-harry

[photopaque]

Just tried you method hmhm...........i can see more dust...damn im really paranoid now.I will mostly be shooting full figure/half figure,portait under tungsten so i would imagine i wont really see a lot of the dust in my pics...but i just want my pics to be as good and as clear as possible.Ive just read about the 'visibledust' cleaning brush.Is this a viable option if the dust doesnt clear after using a blower?