So there I was last night, attempting to teach a friend how to enlarge negatives in my home darkroom. I had a heck of a time trying to track down some pretty big dust spots. I cleaned the lens, negative, blew out the bellows, etc. I still haven't figured out what the deal is, I am thinking it is on the condensor. Is there any problem using windex or lens cleaner on the condensors? I have an old D2.