Where to get lenes multi-coated?

[mental4astro]

If I had an objective lens that wasn't multi-coated, is there somewhere I could take/send it to to have it multi-coated?

Any idea how much such a process would cost?

Could a coated lens (ie one that's not multi-coated) be multi-coated subsequently?

Cheers in advance,

Mental.

[alocky]

I got isaac from C-Qin to recoat both lenses from my 4" Unitron achro. It cost 750, and a great deal of mucking about, as you will need to know what glass was used in the lens because the coating thickness depends on the refractive index of the glass. Although it exorcised the ghosts from my old scope, I'm not sure if it was worth it. I also understand he no longer has access to the coating facility he used.
regards,
Andrew.

[Hans Tucker]

You could try

http://www.longmanoptical.com.au/index.html

[blink138]

hello alex
what sized objective is it? i could probably get up to an 80mm lens done without too much trouble and very little cost
in the opthalmic industry we do not use blanks any larger than 80mm, and that is in plastic
the glass and the plastic multicoat vacuum chambers are different
since all of our opthalmic technology has gone into aspheric and atoric plastics from 1.5 index to 1.74 index materials,the glass multicoating process has stayed the same and i am not sure if the mix of metal oxides are different for the different indices of glass
the lenses are completed one side at a time, so if the glasses are of two separate indices they can change the mix for the other side
if your project is less than an 80mm blank let me know and i will contact one of the owners of my lens laboratory and find out for you
pat

[mental4astro]

Pat, wouldn't you know it, the lens in question is 80mm, :lol: ! Now, that is the clear aperture, I'm not sure if there any overlap, and how much, as I'm still to take delivery of the lens. I'll send you a PM shortly about this project.

Many thanks,

Alex.

[blink138]

ok alex i will check with the multicoat technician to see if the glass chamber can accomodate 80mm, as opthalmic glass blanks never exceeded 75mm
pat