You'll recall the scratched lens was a Takumar-A 28-80 F3.5-4.5 macro\nzoom. Sometime in its life it had been tossed into a kit bag without a\ncap or UV filter, and the front element suffered numerous small, light\nscratches (apparently from sharp metal edges) over half the lens... but\nthankfully not too near the center.\n\nI first applied a _little_ Rain-X and when dry polished with a damp\ntissue. No visible effect on scratches. Next I _flooded_ the front\nelement with Rain-X and and when dry wet-polished again. The lens\ncleaned up fine, with scratches _perhaps_ a tiny bit less obvious now.\n\nShooting a test series at 28mm 50mm and 80mm showed a very slight flare\nat F4 (my *ist-DS on manual mode would not show any F/3.5) which could be\nimproved to "not bad" with a touch of the unsharp mask.\n\nThe flare vanished at F5.6 and above, while apertures F/8 and F/11 were\nquite sharp enough to rescue the lens from the trash can... since\ncurrently its the only true macro lens I have.\n\nI was pleased to find no eueball-measureable barrel distortion at the\n28mm position, even after I drew straight lines on the test image's\nvertical and horizontal elements.\n\nConclusion: though I had not tested this lens extensively before Rain-X,\nit did not hurt the lens, and _may_ have helped. The lens did _not_ turn\ninto a soft-focus portrait lens, which I was willing to risk.\n\nNote that the Z-wax suggested as a repair is not claimed by its\nmanufacturer to fill lens scratches... it is merely a cleaner and anti-\nfog agent, allegedly containing a water-soluable (!) wax.