[Stephen65]

I'll pipe up to say that while its disappointing you had a bad experience usually WO do have an excellent reputation for customer service. In all my dealings with them I've been very pleased with their response, in one particular case they went considerably out of their way to satisfy an unusual request by me.

As far as I know the story about the fluorite is based on the distinction between actual fluorite crystal (CaF2) and compounds that are called fluorite glass (eg FPL-53) which contain fluorite but aren't pure CaF2. FPL-53 is a compound glass with very similar dispersion rating to actual fluorite made by melting CaF2 and mixing it with other glasses, this makes it more homogeneous and easier to work, polish and hold coatings.

A few APOs have objectives (or at least one lens) made of actual fluorite crystal (some Tak scopes for example) but many more are made of FPL-53 or similar glasses and are sometimes described by their manufacturers (including WO) as "fluorite" this or that. Should the latter be called "fluorite" refractors? On the one hand they don't have fluorite crystal lenses, but they do have fluorite glass lenses.

I for example have a WO FLT-132 refractor, I knew before I bought it that the main lens was not CaF2 but FPL-53 but that's because I did my research and WO supplied that sort of information. Since its an excellent refractor and FPL-53 is optically almost identical to CaF2 the fact that it was made of the former and not the latter didn't bother me. In any event the optical quality of an APO is more determined by the skill in which the lenses are designed and assembled than the materials chosen, I've seen tests of FPL-53 refractors that show them superior to CaFl2 refractors (and vice versa of course).

If on the other hand I had thought that it was an actual CaF2 lens, that fact was very important to me and WO didnt disclose it was made of FPL-53 then that would have been something to get annoyed about.