> My question is..Do any of you guys shoot with lenses with small > defects without incident? Or do you feel using a lens thats not at > 100% somehow compromises results... I'm refering to 3-4mm > scratches as on a 35-105 SMC-A f 3.5, not a fungus-and-haze basket > case...
If you have a lens with a scratch on the front element, it may be possible to improve the situation by filling the scratch in with India ink or a black "magic marker". Try to just fill in the scratch, without extending the black ink wider than it has to be. This will have negligible effect on resolution but will improve contrast by reducing flare from the scratch. (And, of course, the black ink will be entirely out of focus and invisible to the film plane.) Light hitting the gouged out jagged sides of a "naked" scratch will scatter all over the place, but making the scratch opaque will prevent that from happening. The loss of aperture is certainly negligible, but there may be a slight bit of diffraction at the edge of the black ink. However, this diffraction may be less damaging than the scattering of light all over the place from the multiple tiny lenses that the walls of a "naked" scratch represent, in effect. (I would not suggest trying this on a scratched rear element, though - the black ink may be somewhat in focus and may be visible on film.) I tried a little experiment involving the above technique once. I took an unblemished A* 135/1.8 lens out of the box, and I ran a ten-penny nail over its big front element. Then I took a "magic marker" and filled in the magnificent scratch that I had just created, but then I dropped the lens on the floor, breaking both front and rear elements, so I stopped any further experimentation at that point. The aperture ring still turned pretty well, though... ;-) Fred - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org .
