What is a fresnel?

[Adam Orton]

OK, if there were a "stupid questions" category to post under, I would gladly place this question there.

 

I know a fresnel is essentially a light that uses a lens to produce an even, consistent spread of light. (That can be spotted or flooded.)

 

I was always under the impression that a fresnel light used a piece of specially shaped glass to reorganize the light, but lately I've heard of something called an "Open-faced Fresnel" that produces pretty even light (from what I've gathered) and can be spotted or flooded the same. But it doesn't use a lens; rather, it's just a bulb with a curved mirror behind it...

 

My question is, what exactly qualifies a light as a fresnel? Is there such a thing as an "open-faced" fresnel?

[Chris Durham]

To my understanding, "Fresnel" refers to the lens, not the light. So a fresnel light is a light with a fresnel lens on it. right?

 

If you look at Arri's lineup, for instance, they have fresnels and open-faces, but the nomenclature doesn't cross. I do think there are probably folks who refer to any directional hard light as a fresnel, but that's incorrect.

[Adrian Sierkowski]

I've never heard of an Open Face Fresnel, as Fresnel is, as you mention a lens. Might be an open face which uses a lensed bulb, though.

[Jonathan Bowerbank]

I've never heard of an Open Face Fresnel, as Fresnel is, as you mention a lens. Might be an open face which uses a lensed bulb, though.

 

Open Face Fresnel is usually when a DP or Gaffer is referring to a Fresnel lamp with a swingaway lens, so you can then make it an Open Face/Eye. It takes away the softness produced by the fresnel element and give you a much harder light source, very good if you're trying to mimic hard sunlight.

 

And yes, Fresnel refers only to the type of lens on the light.

 

http://en.wikipedia.org/wiki/Fresnel_lens

Edited October 21, 2008 by Jonathan Bowerbank

[Adrian Sierkowski]

Ahh, gotcha on the Open Face Fresnel. I've done that before and just called it a Naked Fresnel on my old Mole 2Ks.

[Adam Orton]

Open Face Fresnel is usually when a DP or Gaffer is referring to a Fresnel lamp with a swingaway lens, so you can then make it an Open Face/Eye. It takes away the softness produced by the fresnel element and give you a much harder light source, very good if you're trying to mimic hard sunlight.

http://en.wikipedia.org/wiki/Fresnel_lens

 

 

Aha. That clears up so much then. Thanks!

[Michele Peterson]

I've never heard of a lamp being referred to as and open faced/fresnel. It's always been one or the other. It might be a regional term. You can make a fresnel into an open faced by doing what is called "poking the eye out" which is just removing the fresnel lens (the glass).

 

Poke the eye out of the baby!

Edited October 21, 2008 by Michele Peterson

[James Steven Beverly]

Poke the eye out of the baby!

 

Gaffers have such delicate sensibilities. :rolleyes:

Edited October 21, 2008 by James Steven Beverly

[David Auner aac]

Gaffers have such delicate sensibilities. :rolleyes:

 

'Hey Joe, please hang the baby, kill the midget and have two blondes standing by for the martini!"

 

Cheers, Dave

[Michele Peterson]

'Hey Joe, please hang the baby, kill the midget and have two blondes standing by for the martini!"

 

Hang the black and two-leg the red head while you're at it.

Edited October 22, 2008 by Michele Peterson

[David Auner aac]

Hang the black and two-leg the red head while you're at it.

 

Hehe, that's a nice one too. The one I mentioned above was paraphrased after a part of Harry Box's intro the the Set Lighting Technician's Handbook which is an excellent book. One day, we should collect that kind of joke from all around the globe. Might be a very funny read!

 

Regards, Dave