Does anybody know what the technical name is for the unit that binoculars attach too and you look down with the binocular into a mirror at the sky above.
I would either like to make one or buy one. But as i don't know the correct name for this unit i can't do much research on it.
Cheers
Those flat mirrors used in these set-ups are expensive, and with good reason! It is very hard to make a good flat, and to make a large one that is evenly flat all over is even harder. Getting an flat mirror out of an old photocopier is the way to go to make your own cheaply (I was told the newer copiers either dont have the mirrors or they have shrunk in size considerably).
Yes the photocopier mirrors are front surface and it's true the newer ones are small, about the same size as used in laser printers and flatbed scanners, about 250mm long but only 10 to 20mm wide, so pretty useless for binoculars.
Got one here from an old copier, it's about 60mm wide by 350mm long(guesstimate). unfortunately it's been knocked about over the years and has a few(!) blemishes and scratches.
I've been thinking about it Mick. I need to experiment to work out what size mirror. I'd like to know whether I could get up to my 30x100s using such a system! (Yes, I know the mirror manufacturer says 18x is highest power recommended.) Trying to work out in my mind what the experiment needs to be to determine the size. The other issue would be the dew that would form on the sky-facing mirror. I'm wondering about that as well. So not quite ready to order as yet.
You could put a dew heater on the back of the mirror.
A couple of resistors, a few hours soldering them together (for me anyway) and you're set. They're only 3-6mm thick so it wouldn't take much.
A few blemishes and scratches wouldn't matter as they don't come into focus. You are, after all, focused on infinity not the mirror 100mm in front of your objectives! You don't need perfectly optically flat glass either, although it may help. A piece of float glass will be relatively flat enough to have aluminised and then used in this fashion.
A few blemishes and scratches wouldn't matter as they don't come into focus. You are, after all, focused on infinity not the mirror 100mm in front of your objectives! You don't need perfectly optically flat glass either, although it may help. A piece of float glass will be relatively flat enough to have aluminised and then used in this fashion.
True, but we're not focusing on either the primary or secondary mirrors in a newt either, so I figured they would still have an effect just as scratches/blemishes/dirt/dust on the mirrors in a newt affect contrast and resolution.
Whether it's perceptible thru the bino's, dunno. Might try it out.
"Zenith Prism"? Bojan, I don't know what that is, but I can guess. I've done a bit of googling, but still cannot get a clear picture in my mind. Could you post a link I can check out, thanks.
