Dust in Viewfinder

Hi All,

I have a Canon 40D and there's a piece of dust in the viewfinder. It doesn't show on the images, of course, but I find it annoying and I'd like to remove it. I've taken the focusing screen out and cleaned it and it's not there, so it must be on the inside glass. I've tried a rocket blower with no effect. Any suggestions?

Many thanks,
Dave

Sounds like your doing the right things. Have you been able to locate where the dust is? If not on the focus screen take a look at the penta-mirror. Maybe also the eye piece. I have had a lash in there and noticed it.

Worry about something else. Does it affect your results? No?

The 40D like the 5D has a SI (super impose) plate situated between the focusing screen and the pentaprism (no pentamirror in a 40D). If the piece of debris you mention is in focus but not on the focusing screen itself it's likely that it's actually on the upper surface of the SI plate. Unfortunately the SI plate is not user removable and the camera will need to be disassembled to remove it. I have a suspicion this is as a result of Canon being less hygienic than perhaps they could have been when assembling the pentaprism housing and the dirt has been there since the camera was originally put together. It was just a matter of time before it fell onto the SI plate.