EDoF - how does this work?

[myksmith]

Can someone explain (preferably in a way that's as wonderful as the Tutorials) how EDoF lenses work, ala http://www.xceedimaging.com/EDOF_datasheet.pdf ? I cannot figure out how this works, and I'd love to understand it!

[Dave Humphries]

It's not April yet, is it?

(meaning I don't understand it either)

[Donald]

Their website seems to be pushing this as an innovative development in the broader world of optics, encompassing spectacles etc. The use on cameras seems to be a sort of by-product.

The developers presumably have researched their market and feel there is an opening for this product.

Like Dave, I wondered if it was a bit of a wind-up, but they seem to be serious.

[Dave Humphries]

Like Dave, I wondered if it was a bit of a wind-up, but they seem to be serious.

I haven't seen the rest of the site, but from what I remember from reading that document;
It is very thin.
It can be applied over an existing lens.
Or moulded into a specially designed lens.
Rather than increasing the magnification, it increases the depth of focus.
However, it slightly reduces contrast.

Taking all that together, I'm thinking it must be some kind of microscopic micro-lens array.

Just my supposition though.

Cheers,

[rick55]

I think Dave is right, that it's a micro-lens. A diopter seems to be used (probably misused) sometimes to mean a close-up filter. The article says, it's constructed "from phase modulation of low spatial resolution patterns," and also, "The element can be manufactured by stamping or molding techniques. . . ." Is it too much of a stretch to guess that it's a modern version of a fresnel lens that's moving the focus point and hyperfocal distance of the fixed-focus lens in question?

Cheers,
Rick