Fred, I totally agree. I wish it were only a fine piece of dust or two in a few lenses. I'm not completely anal about keeping my gear clean, but as I was wiping away a smudge today from my 200mm lens, I noticed a "film" of fine particles, almost appearing as if they were suspended in one of the elements. Then I checked a 135mm. Same thing. Then a 50mm. Same thing. My 24mm, not to the same degree, but still there. My 43mm....phew! Clean and bright. But still, nearly every k mount lens has some. My Voigtlander glass looks good however, and I'm just now going to look over my Pentax screwmount lenses.
Chris Fred said: > I personally feel that some dust in unavoidable in many lenses, that > it is not usually picked up in a lens during storage (unless perhaps > the lens is sitting unprotected in a ~very~ dusty place), and that > much (or most) of the internal dust in many lenses is picked up > while focusing and/or zooming. > > Many lenses suck air in, as well as push air out, of course, > whenever the internal air volume changes during focusing and/or > zooming. Unless the air passes through some sort of an air filter > on the way in (such as with the VS1 600/8 and 800/11 Solid Cats), > dust is going to be sucked in along with the incoming air. > > Of course, some lenses (e.g., internal focus designs, typically) do > not suck air in while being adjusted, and may be freer of dust > because of that. > > Fred > >
