I have been plagued by dust motes on the optics of the Zeiss IM microscope showing up on photographs taken with the Bresser MikroOcular camera. Clearly the microscooe has got somewhat dirty in its 30 year history gefore I got it. Lee Bale at RAG recommended using air blower to remove as much dust as possible from optical services to see if this resolved the problem. I dismantled the objective turret and used a Kenair air duster on all surfaces I could get to and also on all surfaces on binocular eyepiece viewer – worked! Dust motes gone except some on one of oculars that will need more intense cleaning. No longer appear on MikroOcular camera photos which is what concerned me.
It is interesting to see that the Kenair does lead to lot of water on surfaces after used – either direct deposition or by cooling them down and leading to precipitation from the air. Certainly, the can gets cold as used.