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Vixen ED Refractors

Started by mnevitt, 08/18/2005 07:59PM
Posted 08/18/2005 07:59PM Opening Post
According to the Vixen web site. Their ED refractors have an ED lens and a Kruz Flint lens. Does anyone know what glass types are used and what level of color correction is achieved?

Mark
Posted 08/19/2005 02:46PM #1
Yes, those of us who design and make refractors all know what Vixen is making. The term "Krus flint" is just a wrong spelling of the German "Kurz Flint" which is a generic term for a crown-flint glass (i.e. one with a dispersion of between 45 and 55). It means very little. I suspect that it was a marketeer sitting in on an engineering meeting, getting the spelling wrong on a term which sounded good to him for advertising purposes.

Roland Christen
Posted 08/20/2005 05:17PM #2
The ED114 f5.3 must have FPL-53 or optically equivalent glass as this design is pushing the envelope for a fast ED doublet. It has been sold as an APO but c.a. is visible on planets but not intrusive. The specimen I have has absolutely perfect star test. I like it a lot for the purpose I use it for.
Lately Vixen is offering a f7.7 version.
This model would profit from a correcting Barlow being reportedly designed by TMB or from a Chromacor-M promised ages ago.