Incorrect.deviant wrote:dust on the actual camera sensor... something that DSLRs are prone to due to the ability to take the lense off.
The dust rarely comes from lens changing, its more to do with the type of lenses you are using, non-sealed lenses tend to be 'dust-pumps'. Do an experiment at home take a zoom lens, off camera, hold one hand behind the rear element (don't touch it!) and zoom the lens with your free hand.
Feel that air? thats full of whatever the environment around you is.
It is not unusual for digtial bodies (from all manufacturers but largely canon?? particularly 5D's.) to come with factory installed dust.
If you stick to primes/lenses with internal zoom/focus then dust will be less an issue.
Newer camera bodies tend to have better materials in the mirror-box which make them less prone to dust.
The most sophisticated in-camera dust removal systems are largely ineffective and additional cleaning will be neccessary. Several companies make products to do this yourself. I like Photo Solutions products, been using them for a long time with good results.
Meanwhile if you are shooting with a dirty sensor then using larger apertures will reduce the visibility of dust spots.
Checking for dust-spots is easily accomplished by taking an out of focus shot of a flat coloured surface with the flash on @ F22, auto-levels in photoshop and there is your dust.
You will rarely, if ever see visible 'spots' from dust in/on a lens. Dusty lenses result in a loss of contrast and subsequently perceived sharpness.
Do an experiment at home, take a 50mm+ lens, a blank UV filter and a permanent marker.
Sign your name on the front element; take a photo at a largish aperture (F8 or larger). You'll see very little difference. I've tested this with a 28mm lens and noticed nothing until about F5.6. This is related to depth of field.
This has been a Lachie service annoucement.
-Lachie
love that fed sq abstract too, lob.