Where to find Large fresnel lens at 3x or 2x?

Does any one know where to find a large fresnel lens of about 24" or so. I have no probs finding those little page magnifiers (7"x10") at like 3x and 6x but nothing the size I need. They seem to go from the small ones right to 10' and etc. that are very expensive. I want about a 2' one like 3x or 2x power. Thank you for any help! Links are Very helpfull and shipping in the US is a must.:)
 
well, unfotunately, before I learned that there were other ways, I bought one of those "100" inch tv plans off of Ebay. I didn`t hear from the guy for about 2 weeks, in which time I leanred how to make the LCD projector, I emailed him several times about how to make the payemnt since I had already bought it, then all of a sudden he emails me back demanding that I pay him immediately. What an idiot...
So now I have two 6x (thats what he says they are) lenses coming in the mail. I really regret not researching this before I bought it.
Oh well. Ya live, ya learn.
 
yep, know what you mean.:( But I didnt buy it for the plans I knew they were already free. But the 6x lenses were very hard to find-so I bit the bullet. Als I really wanted was the lens. It was more expensive that way I know. But this guy pretty freindly and we email each other alot now. Now I think I can get just the lens, without the plans as he's offered me other lenses that he's found.:D All in all-it was my only solution unfortunatly.
 
i rest my case

finally some boys who see the light.

i told someone on this forum that there was a 'slight very tiny. little. alomsrt not noticeable itsy bitsy error regarding the use of a fresnel, and look suddenly voices in the dark saying they need the 'good ' fresnels....." good luck guys but ,y 2 cents on this look in german websites after all they invented these things....

i have some really good plastic ones from austria but i cannot find the maker also, i know for sure that some ex east german co made some, but i have no clue if they still exist!!!!
 
fresnel a little side line info

A Fresnel lens manufactured by a process comprising the steps of:
extruding a highly viscous basic molding compound;
substantially simultaneously extruding a low viscosity molding compound on said highly viscous basic molding compound;
producing a coextrudate from the highly viscous basic molding compound and the low viscosity molding compound; and
embossing a Fresnel lens structure on a surface of said coextrudate formed by said molding compounds by introducing said coextrudate into a nip of a three roll polishing stack, whereby the surface of said Fresnel lens is structured via the three roll polishing stack.

Process for manufacture of fresnel lenses
inventor: Benz, Volker; Hochst, Germany
Berkenkopf, Martin; Pfungstadt, Germany
Fischer, Udo; Darmstadt, Germany
Lorenz, Hans; Darmstadt, Germany
Meier-Kaiser, Michael; Pfungstadt, Germany

And while lots of students (particularly the ones not living in Germany where thaught that the inventor was: Augustin Jean Fresnel, a 19th century French mathematician and physicist, it was actually the german scientist Dauger ( living in the Alsace, (now french but then german) who did the research and design!!
ANd then there is Fraunhofer.... a guy who tested a kind of deflecting lenses very similar but a bit easier to understand.

No wonder Germany wanted to teach those French a lesson 2 consecutive times!!!
 

sai

Member
2002-10-19 9:51 pm
NYC
uh huh

yep..... but seriously, does anyone know which local store or types of stores (ie. electronics, video, etc.) i can find 3x or 6x lens???:bawling: also, i am using a CRT monitor. is it better to use 2 lenses in this setup. i've seen plans where one fresnel lens is pressed against the monitor and the other is about a foot away. does this actually work :confused:
 
I heard from another message board that pressing a fresnel directly against the CRT screen and then another one a foot away (or however far) works really well. Apparently the first fresnel straightens the light coming off the screen, and beams it to the second fresnel. Apparently the brightness and clarity is much better than just using the one fresnel a foot away. Plus, you dont have to turn your CRT upside down, and the image isn't backwards, because the image is flipped twice!

I wanted to try this myself, but I only have one small fresnel that I ripped out of an altas I have lying around.

Somebody with 2 fresnels should try this!

Also about the 6x fresnel, I heard that these were nearly impossible to manufacture. The people on ebay say they are selling 6x fresnels, but they are really just selling two 3x fresnels...
 
There is no such thing as a x6 fresnel (according to the guys who make them at 3dlens.com)

anyone who sells one is lying out their ~~~~

I sell the lenes in the UK, but 3dlens.com is a little cheeper than me (i wont lie!) but i can send faster and you dont need a credit card.
www.DIYprojectionTV.tk

I ONLY have the smaller A4 siaze lenes and have never been able to find larger.

I do a the fresenl off a OHP, but this does nto work as this is to spread the light, not to focus the image.
 
spreading the light

quote"I do a the fresnel off a OHP, but this does not work as this is to spread the light, not to focus the image."end quote.


hummm interesting so you say that the horizontal fresnel of a OHP spreads the light??? hummm, i guess i seem to have a little problem there as the Dukane 4003 in front of me has a fresnel that collects the light .....