difference between "spot" and "linear" fresnel lenses?

[Juan Samwells]

What is the difference between a "spot" and a "linear" fresnel lens? How
could I confirm which type I had if I had a fresnel in my possession?

Thanks,
Juan

[slu...@lw4u.com]

Okay, I'll admit I'm stumped. I've never heard such terminology
related to Fresnel lenses. Where did you hear/see these designations?

One possibility that comes to mind is that a "spot" lens might be a
more standard type that behaves like a spherical plano-convex lens,
and allows you to focus a light source to a spot. The "linear" might
be a Fresnel cylinder lens that lets you project a light source as a
line.

Anyone else?

Spencer

LIGHT WORKS, LLC
http://www.LW4U.com

[Boxman]

> One possibility that comes to mind is that a "spot" lens might be a
> more standard type that behaves like a spherical plano-convex lens,
> and allows you to focus a light source to a spot. The "linear" might
> be a Fresnel cylinder lens that lets you project a light source as a
> line.
>
> Anyone else?
>
> Spencer

Spencer's explanation is the same I've heard before as well. A linear
lens usually refers to a fresnel that only has prisms running in one
direction and creates a line focus whereas a spot fresnel has the
circular rings that produce a focused spot.