Fresnel Lens - Maxwell Simulation

| 8 Comments

fresnelLens.jpg

I had originally assumed a Fresnel lens would be too hard to make work, but I decided to give it a shot, anyway. I grabbed a cross section from wikipedia and made a surface of revolution from it.

It functioned quite similarly to the plano-convex lens - exactly as advertised.

fresnelLensWire.jpg

I nudged the light source closer and farther until the beam looked fairly parallel. No calculations involved.

Here is the Maya / Maxwell file

FresnelLens_test.mb

UPDATE 1/8/2010

Here is the lens in .obj format

FresnelLens-OBJ.obj

8 Comments

Joseph,

This is similar to some experiments i want to do in maxwell but i'm only using studio (not maya) so i can't use the file you supplied. Can i ask how you got the light rays to show? I didn't think maxwell did volumetrics? What's the secret!

any info, most appreciated!

great work

paul

I'm sorry to say it's not volumetrics. :( I just ran a plane down the middle of the lens, cutting it right in half. That's why in the wireframe above you only see half of the lens.

I describe the setup in more detail here:
http://www.digitalartform.com/archives/2009/04/parabolic_ellip.html

...and I should have carried that information through to this post on Fresnel lenses. I'll probably amend this post to be clearer now.

Thanks for writing.

Joseph,

That's fantastic, i was just looking through your site over coffee this morning. Very interesting work, whilst i don't quite go back to the same days as you i remember the old wavefront and poweranimator times fondly.

cheers
paul

I have read and understand how a fresnel lens works for a lighthouse. What I do not understand is how the same principals are used to manufacture a thin sheet of plastic that one can buy, usually described as a linear or spot fresnel sheet. Is a sheet simply the same fresnel orders repeated row after row? What is between the rows if anything? How would the circular fresnel sheet spot focus instead of linear) employ fresnel's differing lens?

Hi guys, i googled this page and was enjoying your comments.
Here is a link to more fresnel lens used in lighthouse:
http://www.michiganlights.com/fresnel.htm
just for fun:)

Would it be possible to get a hold of this export in 3DS/DXF/OBJ format?

Thanks in advance!
Adam

Adam,

I uploaded an OBJ format lens for you.

Thankyou - going to play with it in a couple of the other rendering engine to see what results I get - now I just have to work out how to build other types of lenses :)

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This page contains a single entry by published on April 13, 2009 12:01 AM.

Fresnel Lens, Plano-convex Lens, Collimating Lens was the previous entry in this blog.

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