NewBie
*Retired*
Okay, for a few days now, I've been slowly polishing an ARC4 reflector with some Brasso and a nice soft old diaper, in order to attempt to remove all the grooves in it when it was made.
FYI, it was machined, not very finely, and then overcoated with a urethane sort of coating, which smoothed in the roughness of the machining. No sputtered/vacuum deposited reflector coatings or anything.
Anyhow, half way through the process, I thought I'd get a shot of the sun in order to show the focal point, and how precisely it was made.
For your viewing pleasure:
Here is another shot which shows the machining marks better, note they are rather smoothed down now. Before removal of the clear coat urethane (the urethane hides alot of the machining (smoothing it over), and all the polishing I've been doing, it was much prominent:
FYI, it was machined, not very finely, and then overcoated with a urethane sort of coating, which smoothed in the roughness of the machining. No sputtered/vacuum deposited reflector coatings or anything.
Anyhow, half way through the process, I thought I'd get a shot of the sun in order to show the focal point, and how precisely it was made.
For your viewing pleasure:
Here is another shot which shows the machining marks better, note they are rather smoothed down now. Before removal of the clear coat urethane (the urethane hides alot of the machining (smoothing it over), and all the polishing I've been doing, it was much prominent: