View Full Version : flourite lens


Michael Bendixen
June 8th, 2004, 09:41 PM
Can anyone tell me about what this means. I've read some info on past threads but I'd like some more. Also, how does it compare with the lens of the PD-170, which I heard is also a Canon?

Ken Tanaka
June 8th, 2004, 09:58 PM
Flourite is a naturally occurring crystal that's mined in various places around the world. Canon has a patented process and design for incorporating optical elements made of flourite in some of their high-end lenses (ex: some of their "L" series photo lenses and, of course, the GL2's lens) to minimize distortions. You can read a short blurb about it here (http://www.usa.canon.com/html/eflenses/technology/lseries.html).

I don't know about the 170's lens, but I doubt it's made by Canon. The optical image stabilizing ("SuperSteadyShot") might very well be a Canon product.

Michael Bendixen
June 9th, 2004, 04:36 PM
Thanks for the info and link Ken. I've read similar info about flourite from Canon before, but I wonder the distortions it minimizes are noticeable or is it just a marketing ploy?

Jeff Donald
June 9th, 2004, 05:39 PM
Fluorite reduces all types of chromatic aberrations. (http://www.dvinfo.net/articles/optics/lensdefects.php) Nikon uses ED (extra low dispersion) glass. It works about the same, different material.

Ken Tanaka
June 9th, 2004, 06:50 PM
Fine photography, and particularly the physics of light diffraction, is an extremely complex field. While Canon's marketing strategy certainly touts their use of flourite, it's not fluff. It's an expensive and intricate process that's offered only on Canon's high-end lenses and that truly aids in producing some magnificent results. If you want some casual testimony, look around at an event that draws professional photographers. How many white-barreled lenses do you see? Each of those, and many of the black barrels, is a Canon 'L' series lens.

Of course such a high quality lens would generally be overkill for taking just-fooling-around photos at relatively low resolution.

Jeff Price
June 10th, 2004, 09:45 AM
Fluorite is also used in some of the more esoteric branches of photography. For example, photography in the near UV. Nikon makes a specialty lens for just this application. It costs $5,000 and is made out of fluorite.

Some of the top of the line spotting scopes are also made with either fluorite lenses or ED glass. All to pass through the "truest" frequencies of light and reduce aberrations (and, yes, it is noticeable under the proper conditions).

Hagop Matossian
June 10th, 2004, 08:59 PM
good old canon.