If this is the flourite lens it is special because it transmits ultraviolite light which is useful in some scientific and industrial applications, and because the flourite has extremely low colour dispersion in the visible wavelengths (hence the "Ultra-Achromatic" moniker). It is expensive because flourite is very much more costly than even optical glass. It may also have a rarity factor in its price.
Regards, Anthony Farr ----- Original Message ----- From: <[EMAIL PROTECTED]> > What makes this lens so special and expensive? > It's intended for B and W? > Please enlighten me > > Albano > - - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org .
