Pawel Bartuzi wrote on Tue, 17 Apr 2007 15:13:32 -0700: > Hello, > > What is your opinion on lens cleaning? I mean not the usual > cleaning but > professional cleaning involving taking the lens apart and cleaning all > of it's surfaces? > > I ask this question because I have several K primes which are now > about > 30 years old and although the pictures made with them are nice, when > inspecting the lens with strong flash light I can easily see > amounts of > dust sitting on all of the internal surfaces. On some of the lenses, > like SMC K 18/3.5 - where there are 12 elements in 11 groups - I can > imagine it does affect the image quality (and indeed, the lens is soft > on the edges of the frame). > > I wonder whether thorough cleaning of the lens done by a professional > does improve such lens performance by a significant margin? Does it > raise or lower the lens value? What is your opinion, your experience?
Unless you have a LOT of dust in your lens it is unlikely have much effect on your images IMO. Regarding low edge sharpness with your K18/3.5, I have this lens and the corners are rather soft below f8 on images made using my *ist-D, so I think that this is probably normal behavior for this lens. My copy does have some scattered dust particles in it, as do most of the lenses in my collection. Regards, Jim -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net
