Which fresnel is better for a 7" LCD ?

[Andronico]

Hi people, I'll begin with my 7" LCD projector unit. The specifications will be :

- Lilliput 619GL-70NP/C
- 110W/NDL (OSRAM POWERSTAR HQI-TS)
- Condenser 90mm diam FL 100mm (from Surplus Shed)
- Projector lens : FL 220mm (from American Science & Surplus)

My problem are the fresnel : I was looking at 3Dlens.com and found three possible choices :

item #406 : http://www.3dlens.com/fullpagemagnifier.htm

item #A260 : http://www.3dlens.com/largefresnellens.htm

and item #OHP280 : http://www.3dlens.com/overheadprojectorfresnellens.htm

Please, can anybody tell me which is better and how many I have to use in order to obtain a good result ? And about my projector configuration, any suggestion ?
🙂

 

[bulldog5046]

be best off with 1 of the ohp fresnels, as it says it is 2 fresnels stuck together this is known as an unsplit fresnel, when it is just a single fresnel lens it is known as a split fresnel, if you purchase the OHP fresnel you place it before the lcd, if you need any more help just ask, altho you will tend to find people dont want to help n00bs because all the info is already in the forum somwhere.

Cheers,
Ryan Edge

 

[Andronico]

Thank you Ryan ! 🙂

 

[go77306]

I am using 200mm fl fresnel now, haven;t finished my box yet. initial test is soso, I need to build a box for it, and see if that makes any difference. If it works, I'd suggest 200mm ones, since the groove is 0.2mm.

 

[mparker]

go77306, whats you projection lens?

 

[go77306]

240mm FUJI copy lens.

check out my thread here:

http://www.diyaudio.com/forums/showthread.php?s=&threadid=40152