Re: Parametric Optics/Secondary Suppliers
Bob Luffel (bobl@hpgrla.gr.hp.com)
Mon, 1 May 95 18:31:09 MDT
>
>
> Does anyone know the address/phone of Parametric Optics (maybe in
> Florida). A friend of mine ordered a flat secondary from them a few
> years ago but he doesn't have the address. He says they guaranteed
> 1/20 wave error.
>
> Any recommendations for other suppliers of high quality secondaries?
> I recently finished a 10" f/8 for our club. The mirror came out
> really nice. It will be a good planetary scope if we can get
> a secondary that won't be the limiting system component.
>
> Mark Wicks
>
E&W makes good secondaries, but you may (probably) have to wait a while
on them to make some more if it isn't a size already in stock (I have
been waiting 3+ months on a 1.5"). I have tested two (a 1" and a 2.14")
and they are as advertised (1/20 wave, I believe). Most of their sizes
are fused quartz, also. Since you will be looking for a small secondary
(less than 1.5", I presume, for an f/8), you will probably find that
most secondaries of this size are quite flat. Making the larger
diagonals flat is what gets tough, evidently.
Bob