--- Brent Watson <brentjwatson@yahoo.com> wrote:
No I didn't do any throughput testing. I do think the contrast increased slightly, but the secondary color also is more apparent (My estimations).
If the coating tint is blue, then you should see a slight increase in the red end of the spectrum (yellow, orange, red) and a decrease in the blue. Very slight. Is this what you see? Did he do all four surfaces of your objective?
John Ross does this in his basement at home. He is retired from Hiill AFB where he did this for a living. Therefore, he has no brochures, no web site, and works from word of mouth only. He will do any coating, including aluminum and gold.
Sounds like he's doing vacuum deposition and not a chemical etch, yes?
Some folks around have a different opinion as to quality, but Ihave had no complaints with his work. He can do up to about 16" optics.
I would like to speak with him; if he can give a working coating, this is a boon to local bottom feeders like me. But, if it's just a blue tint with little or no througput gain- well, I don't pay money for "comfort factors". I work only a mile down the road from Skypark, Brent, how often are you at the hangar? Ever have lunch at Leger's? Maybe we can get together for lunch one day soon. BTW, some of the "do-it-yourself" coating article has come back to me- I seem to remember that it was a nitric acid dip, with some neutralizer afterwards. The acid pits the optical surface on a 1/4-wavelength scale, so you get the same effect as a deposited coating- the light reflecting off the bottom of the pits is 1/2 wave out of phase with the light reflecting off the unpitted surface. Because the pits are so small, optical performance is not negatively affected, in fact is increased due to the anti-reflection properties. You can't even detect them during testing. But nitric acid is really wicked stuff. I wouldn't recommend this for anyone who hasn't had at least AP Chemistry in high-school, or a college lab of at least the 300 level. Chuck __________________________________________________ Do you Yahoo!? Yahoo! Shopping - Send Flowers for Valentine's Day http://shopping.yahoo.com