Plastic Crap Lenses or High-Tech Precision?

[Mike Johnston]

Raimo wrote:

> What do you mean with the statement "it's the least accurate" - we are talking
> about very small tolerances, about 1/1000 of millimetres here. The polymer
> layers are that thin. Do you have any data to verify your conclusions?

Raimo,
No, I'm a journalist, not a scientist, so I have _sources_ to verify my
conclusions. <g>

A good deal of what I've heard about aspheric lenses was told to me by Chuck
Westfall of Canon, who asked the lens designer in charge of aspherical
optics at Canon Tokyo some questions on my behalf, and who then wrote a very
complete and valuable primer about aspherics in an e-mail to me three or
four years ago. For two years I tried to get him to expand that e-mail into
an article for _PHOTO Techniques_, but he could never get the necessary
clearance from Canon. Unfortunately, I'm not at liberty to share Chuck's
e-mail (or at least I was asked not to publish it, and I'm not going to
split those hairs).

--Mike

-
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.