The Canon EOS and Photography Forums

I photograph wildlife, which takes me to various locations in Africa and Asia where dust is a big problem for my Canon digital SLRs.

I was wondering if there was a lens adapter that I could attach to my digital cameras and never take off. I would attach my lenses to this adapter. That would enable me to change lenses in the field without getting dust in the camera sensor.

This adapter would be clear glass and not alter metering or any other lens /camera function.

In a word, no.

The best you can do is either (1) use a wide to telephoto zoom (which will obviously compromise image quality) or (2) take care when changing lenses. If it's really, really dusty and windy when you want to switch lenses you might consider changing the lens inside a clean plastic bag.

A "window" as you describe could work, but in order not to affect the lens it would have to be well inside the camera and thin. Even a plane glass sheet will affect the optics when placed behind a lens. Lenses with rear mounted filters account for the presence of the filter in the light path in their optical design. Though the effect is small, a plane glass window is an optical element when placed at the rear of the lens. On the front of the lens it doesn't have the same effect of course.

You could, I suppose, leave something like a Tamron 1.4x TC attached to the camera at all times, but (a) then you couldn't mount and EF-S lens, (b) you'd lose a stop, (c) you'd degrade optical quality a bit, (d) your wide leses wouldn't be so wide and (e) your slower lenses might not AF well.

Dust Aid makes a product callled Dust Shield that is designed to do what you ask. I believe Adorama has a few for the Canon 5D and 5D2. I wouldn't think they are worth it but I really don't know.

http://www.dust-aid.com/08dustshield.html

Edit -- Appears the "only" Dust Shields made at this time are for Canon's 5D & 5D2.

Maybe it is time for a spare body?