WO Fluorite Doublet Megrez

[Stephan]

Hi All,

I was thinking about buying a WO Fluorite Doublet Megrez because the price seemed very good for a Fluorite Apo. :D As I was looking for some reviews I found out that it does NOT have a fluorite crystal lens rather it has a lens from glass which contains the element Fluorite. :eyepop: What is much cheaper to manufacture but unfortunately it doesn't have the good optical properties of a fluorite crystal.
I have decided that I won’t buy one because for a normal ED-doublet Apo the price is quiet high. It’s really a pity….. :sadeyes:

[Dennis]

Wow - good thing you did your research Stephan – it pays to know exactly what you are buying. I understand that modern fluorite is artificially grown rather than the older stuff which was naturally occurring and was quite fragile.

Cheers

Dennis

[Lester]

Thanks Stephan, great info

[Miaplacidus]

Well, yeah, I guess. I mean, it is important sometimes to know exactly what you're buying. But in the end, surely, what matters is how it performs optically under the stars. After all, naturally occuring fluorite glass was the secret lens element "X" that Abbe Zeiss famously added to his triplets, and no one worried then that it wasn't grown in a laboratory. How exactly do the two forms differ? Where did you find this info, BTW? I'd be interested in reading more.

[Stephan]

I agree, the performance of a telescope counts, not how it is made or what is in it. Regrading the Zeiss triplets (I am assuming you mean the APQ-series) they used lab grown Calcium-Fluorite. As the lens has to be a giant single crystal and therefore it is very hard to grow and it is also very brittle. That makes it difficult to polish (that is what makes real fluorite-apo's so expensive). The WO-Fluorite on the other hand does not use a Fluorite-lens. They only mix some Fluorite in the glass. Therefore WO should not call it Fluorite-Apo but they do anyway because there are no trade rules or anything. Skywatcher (Orion etc.) could call the 80-ED refractor also Fluorite-refractor because their ED-glass contains fluorite too. The bottom line is WO should not call their fluorite refractor Fluorite-Apo but as there is no law so they do it anyway...

Stephan

[rogerg]

I noticed this thread on the WO Yahoo! group the other day. Still don't really have a strong opinnion about it.

I guess all I know is if the FLT 110 that I've worked with several times (owned by an astro friend not me) is one of these "semi fluorite" lenses, then good on'm because in my opinnion, it has the sharpest optics and best mechanics I've ever seen, unbelievable scope and worth the money if you have it. If it is a true fluorite then I'd be interested in seeing a comparison myself between the types, visually, before making judgement.

Roger.

[beren]

I think I had the good fortune to look through the same one as Roger and agree 100% , superb instrument :thumbsup:

[pluck]

I've just bought one (80mm FD) and it is superb - look for my comments in the yahoo William-Optics group if you're interested. I too did a great deal of research, and for me the Megrez represented the best quality for price I could find. You can spend a lot of money on refractors, and can rapidly reach a point of diminishing returns (ie, price versus view). I'd recommend you take a second look at the WOs - very few owners have anything bad to say about them.

Paul