Thanks for the advice, it raises another question. What would the maximum workable distance from my eye to the knife edge be? One problem I have is that the tester design seems to favor the use of my left eye to get closest to the knife edge, needing clearance between my head and the lamp housing. Unfortunately, my left eye was damaged in a childhood accident and has uncorrectable defects (it's like looking at the world through a smeared dirty window). I could try to re-make the lamp housing to a smaller size so I can use my right eye, but I'd like to know how close I have to get. I'd rather not have to toss this setup out and build a left-handed (right-eyed) tester. Thanks again for your help.

• Tester - bobmay - April 21, 2002 - 03:39 UTC
• Re: Thanks-got another question - jkoptic - April 21, 2002 - 03:48 UTC