Fresnel Lens types

Name three type of Fresnel Lens. There is four types of Fresnel lens that have been used in the industry over the years.

No, not step or PC... there is three different types of Fresnel lens, what are they in major differences?

 

Well, since you just said 3 types of "Fresnel Lenses", here are 7 types that they use for lighthouses. They are in order of size biggest to smallest.

First Order
Second Order
Third Order
Third and 1/2 Order
Fourth Order
Fifth Order
Sixth Order
(I got this information from http://www.michiganlights.com/fresnel.htm)

and also, the Hyperradiant is larger than First Order (Wikipedia)

I also read they are making some inflatable types used for solar power. (thought that was interesting)

But, I have no idea what types they use for theatre, and I could not find the answers anywhere.

 

A few were hinted at in a post about Fresnel lenses out of the lighting part of the forum.

 

I think we give up now...

 

GAAAAAAAAAAAA! Ship, give us the answer.

 

Oh' come on now, nobody has really looked into the answer.

I'll give you one.

What's the difference between a Fresnel lens that is just a Fresnel lens and one that has parts of it's surface painted in - could that be an example of one that's while the same in general description going to be of a different use?

Three more types to go by my counts as specified in some long past book that gets into fixture theory design and construction really well = this long before DMX or computers were considered or thought of for theater.

 

I have searched everywhere on the internet, and could not find anything.

I give up.

 

Keep searching or I believe I have mentioned a few really good older books one could Amazon or E-Bay and or hints on other parts of the forum. None the less, if not minded too much, let's say give it a month of other's attempting to figure it out. Imagine if in books, if just these lens types are not mentioned sufficiently in modern books, what else are you missing out on...

Really is that many Fresnel lenses that are engineered to do different things one might find on stage - especially if using older gear. I'll give a second, the oval Fresnel lens or what's possibly the same as what's called the "Ovalite." ("Possibly it's a different more PC lens instead in use on a Ovalite, but there is specific meniton of a Fresnel oval lens.) Never seen one myself but it's specified as a Fresnel lens type.

Also in such old books would be the concept of why the above painted glass to the inside angle Fresnel lens would be different enough to mention as different than a standard Fresnel lens.

 

I'll give it a go, looks like a challenge!

 

This is so flustering, I've just got to try to figure this out...

 

Gee my first time here.
I have no idea what fresnel types are by name, but I currently work with two. One is a fresnel front with the lamp side of the lens flat and the other has the lamp side. in a con cave stlye--not refering to a steped lens, though that could be considered a third. I have the Fuchs book so maybe I can research it if I remember.

There is the possibility that the flat back sides either hava a pattern or are clear.

 

<hijack> Welcome aboard! Some of us have been trying to figure out this question for a while. (I haven't found what I think is the answer yet, but I'm gonna post if I do!)</hijack>

This is a real hard one ship!!

 

I did some quick research.

T. Fuchs book predates fresnel lenses in Theatre. The W. Bellman book (mid 70's) noted cheap lenses and expenseive lenses, cast lenses and ground lens with the step lens a variation of the fresnel. If there is something else then it is beyound simple research and will make us all feel stupi d

 

Nice books to read...

Flat verses concave shape to it.... Hmm, why would one wish to do that?


Welcome to the forum, sounds like a great start you have already made.

 

This is specifically about Fresnel lenses, no step lenses were intended to be a part of the question but it's an interesting observation on a possible type.


Feel free also to do your own question of the day's - as you can see, at times the most simiple things or odd concepts take off as interesting questions.

 

By my counts, we have all four of them mentioned now. Anyone wish to sum up the four types and explain the differences between them?

 

Not quite sure of the optics on a con cave backed Fresnel Lens. However it does seem to capture more light and produce a wider and brighter output. Specifically refering to the ARRI line. Curious how the 5" lens in an ARRI Jr with a 1000w EGT lamp, produces alot more output and spread then an EGT in a Mole 407 with a plano back lens.

Gee am I on the right track? I seemed to have hit a nerve.

The only lens that I can recall seeing with black paint on the steps where Kliegl 1355 line, but they where step lenses. Not a correct answer.

( For the unitiated I work in a small TV studio, but do, and have done lots of live stage work.Studio rated equipment such as Mole and ARRI and B&M are pretty much required.)

Hey you can always read S. McCandless's books.

 

Painted
Coated
Standard
Concave

Few more im pickin outta here

Cast
Ground
Inside angle?

This one WAS hard. Wish I coulda seen if the library had any books.

 

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You asked for three types of Fresnel Lenses, but you said the above.
So far we have the plano lens (most with a pattern to defuse the light), then there is the Con-cave Fresnel Lens, the Oval Stlye, and the not correct for this question the step lens. That is four.

The other variations include cheap and expenseive, cast and ground. You also mentiond painted, that would be to control some scattering of the light.
Assuming that you are discounting the light house lens, what else is there, except enough money to buy what we need.

Oval tends to give a flattened but broader pattern, standerd plano is a good workhorse with a good balance of spread and brightness, con-cave is smoother and brighter and finally step lens does not count, but has been used instead of two plano convex.

Sums it up as best I can figure from the contents of this thread.

 

I quote from the origional question.

Anyone else want to attempt to sum it up and explain the differences between the four types of lens? For instance, the Concave style Fresnel lens was gotten into a bit by gaffer240, anyone like to confirm or correct his observation? Also, Good definition or description on what the oval Fresnel lens is going to do. Possibly include it into info on the other three types including the Concave?

I wouldn't call cheap/expensive a type of lens - define how you can tell, otherwise if they are types, define the differences.




Light house Fresnel lenses I wouldn't classify as being used in the industry either.