Check those rear elements! When I bought my used SMCP 135/1.8, I was dismayed to find that the rear element had on it what appeared to be "cleaning marks" that looked just like circular scratches. No amount of normal cleaning with commercial lens cleaning fluids removed these "scratches", and I was almost resigned to accepting that the marks truly were scratches. Upon magnified examination though, I could see that what appeared to be scratches were actually deposits of some white encrustation. When I checked with my technician, he suggested I use carbon black - dry, with a soft lens cleaning tissue. After cleaning with carbon black using very small circular motions, the lens was clean and free of these marks and was back in "new" condition. From that day, I have promoted the use of carbon black for cleaning lenses. If you try this, use an exceedingly small amount of carbon black. A one ounce bottle should last you for your entire life and that of your progeny.
Regards, Bob.... -------------------------------------------------------------------- "Beer is proof that God loves us and wants us to be happy!" - Benjamin Franklin From: "Paul Franklin Stregevsky" <[EMAIL PROTECTED]> > I seldom check a lens's rear element for cleanliness. One of my recurring > fears is that in the year 2030, I'll discover that on each of my lenses, the > rear element has a big smudge that has been degrading my results for > decades. > > Pat White <[EMAIL PROTECTED]> wrote: "Or, to put it another way, putting any > filter in front of the lens will cause _some_ image degradation (loss of > contrast or sharpness). An SMC filter will cause the least degradation. In > some instances, the difference is hardly visible, but for people to whom it > matters, the few extra dollars are money well spent." > > [EMAIL PROTECTED]@verizon.net
