Hallo, Maintenance Question: I have a speck of something which is visible inside, on the pentaprism when the lens is off. Invariably, it appears in the viewfinder window when taking pictures. I have tried to remove with air or a light brush but it refuses to budge. Someone told me that it was inadvisable to interfere with a pentaprism as they are very sensitive. Better to send it away to be cleaned. Can I do this myself? The camera in question is a minolta dynax 5. Many thanks for any help, M.