Difractive Lenses

[Ant]

I've been studying a lot about light rays, and lenses, focal lengths, apertures, and constructive/deconstructive interference recently in my final year of electrical engineering.

Made me wonder, what other lenses are there about, rather than the normal bunch of lenses with just meniscus/biconvex/biconcave elements in them.

I jumped onto the internets, and found that Canon do DO lenses, that's Diffractive Optics. They claim to be much smaller and lighter to that of the normal, conventional style of lens.

Such a lens, as it's relatively new technology, doesn't go as wide with the aperture as normal lenses, but i think the lightweight of the lenses would make up for it.

So i'm wondering, what are peoples thoughts of these lenses? I've read that they need a little more PP and sharpening than taking photos with the normal style lens, but i'm wondering whether anyone has actually had a go with DO glass, and what you think of it!

 

[arclight]

Never heard the name Must admit - had to Google it to find out what it was (Google found your post).

Don't know what photographic application there is. Seem to be used for lasers and contact lenses.

Appears to use a series of concentric rings in the glass and that rang a bell. A bit like fresnel lenses which were used in SLR focussing screens (and lighthouse and railway signal lenses to centrate the light beam).

 

[CSB]

Canon make a few lenses that use DO glass, This review has some details and also links to other interesting articles.

I've never used one myself.

 

[malla1962]

The fact that canon only make 2 tells me a story.