Quote:
Originally Posted by gregbradley
Hi Bill,
Be careful of misleading marketing hype by some manufacturers. Fluorite is the term usually given to CaF2 lenses. This is a crystal of calcium fluorite made in a furnace and is a costly and polluting process.
ED glass has fluorite in it. But its a glass, its not fluorite. Fluorite is a crystal and is the slightly superior lens. Hence it commands a premium in camera lenses and telescope lenses.
...
The only telescope maker I am aware of that currently offers fluorite lenses is TEC. Noone else, including Astrophysics or Takahashi.
Greg.
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Thanks Greg for the information re: flourite per se in the context of the 120mm OTA that Andrews was advertising
I'm well aware of the differences these days especially if its for our scopes - yep, wouldn't we all wish that real flourites would cost us cheapo prices eh?
In the good old days photographic flourite lenses were the bees knees too! - I remember Nikon and Canon had pro series of flourite lenses that only the rich & pros could afford!!
Cheers
Bill