Calcium fluoride vs Fluorite vs Fluoro crown

[Hans Tucker (Hans)]

I had, maybe still have, concerns over the decal that was put on an APOMAX I purchased a few years ago.

[anj026]

Here is an LZOS OK4 doublet.
http://www.apm-telescopes.de/en/Tele...er-ED-Apo.html

And here are some nice big fluorite doublets for when I win the Lotto!
http://www.apm-telescopes.de/index.p...=1191&sorting=

[LewisM]

So what is in my Vixen FL102S? I know it's a doublet, but what is the Fluorite/Fl crown status of these fantastic scopes (with NIL chromatic aberration)

[Kunama]

Originally Posted by LewisM

So what is in my Vixen FL102S? I know it's a doublet, but what is the Fluorite/Fl crown status of these fantastic scopes (with NIL chromatic aberration)

I believe the FL102S fluorite optics were supplied by Canon-Optron, I also read somewhere the FL102S has the fluorite elements behind unlike the FS series Taks which have it in front. I'll try to find the reference.

[Hans Tucker (Hans)]

Originally Posted by Kunama

I believe the FL102S fluorite optics were supplied by Canon-Optron, I also read somewhere the FL102S has the fluorite elements behind unlike the FS series Taks which have it in front. I'll try to find the reference.

The FC Series Takahashi Refractors also had the fluorite element at the rear. I believe the optics for the Takahashi refractors are supplied by Canon.

[LewisM]

Thanks Matt and Hans. I seem to recall that too, and there were 2 distinctly different FL102S's also - not only differing in focal ratio, but also quality (the slightly longer focal ratios being inferior optically)

[PeterHA (Peter)]

Dear All,
Calcium fluorite is for all intents and purposes stable for use in telescopes when stored in the usual dry conditions.
Occasional dew is not a problem and it can be cleaned with Isopropyl Alcohol like other high performance optics.
I personally like no dew on my optical surfaces as it makes dust stick better, I use dew heaters to keep them dry.
The Vixen FL are doublets with a Calcium Fluorite element.

[Kunama]

Originally Posted by Hans Tucker

The FC Series Takahashi Refractors also had the fluorite element at the rear. I believe the optics for the Takahashi refractors are supplied by Canon.

The new FCs also have the CaF2 at the rear of the doublet.

[Kunama]

Originally Posted by LewisM

Thanks Matt and Hans. I seem to recall that too, and there were 2 distinctly different FL102S's also - not only differing in focal ratio, but also quality (the slightly longer focal ratios being inferior optically)

I think the FL102 came first @ 902mm, followed by the FL102S @ 920mm.

[LewisM]

Yes, I have it bass akwards. The 920's were slightly better than the less encountered 902's