Better Design Using 3 Fresnel!!!

[buddy123]

Could someone explain how this 3 fresnel work?
According to the site thread, you can translate it to english....
http://web102.sun-15.de/forum/phpBB2/viewtopic.php?t=3258
http://web102.sun-15.de/forum/phpBB2/viewtopic.php?t=3258&postdays=0&postorder=asc&start=50 <-look for duffy
____________________________________
Burner - 4cm - condensor lens - 8cm two Fresnel 310mm and 210mm (grooves together) - 1.5cm - TFT - 2cm down 4cm above - 310mm Fresnel --(175mm)Projection Lens

Waaaaaaas?!?!?!
then raff I net. If your first Fresnel has 310 mm, then she should be nevertheless approximately 31 cm away from the burner.
if you use nen condensor lens, then one can to-bring her still another piece more near, but with you those are then only 12 cm!!!!!!?????
How gehn that? * nixraff *
buedde clears me up


No notion why you do not understand it, I have 310+210 = 125mm and a 310mm focus has 5cm diameter
_________________________________________

So if you have an ohp combined fresnel with f1:310 and f2:210,
you dont arrange it like bulb--310+210--LCD---210(Projection)???

So the combined focal is all that matters???
Bulb--125mm--(310+210)fresnel --LCD--310---
Another question, what's the purpose of the 310FL???

 

[part2wanksta]

yeah i have seen a couple of designs with 3 fresnels.

i think i might do another one.

all of my lengths are really short so i might need the third fresnel.

heres my idea

light--3"--lexan--3"--ohp fres-lcd-ohp fres-4"-movable fres-3"-lens

or

light--3"--lexan--3"--ohp split frenel-lcd-4"-movable fres-3"-lens


tell me what you guys think