DIY Video Projector Part II

[mathias]

Sorry, with refration I mean dispersion (rainbow effect).

[ace3000_1]

Mathias, what about the blue spectrum? there is red green and blue to make up white light, the rainbow effects wont accur on a lcd, ive never seen this and about all u would see on a miss- matched light system is a blur, the rainbow effect could possibly be seen if the operating frequencty of the light is lower then the lcd's but even then with light combined already coming from each source combined into 1 u wont see this effect, the lcd filters this light with its own static colour filter. Dlp has this issue because the light beam is filterd into colour and operates at strict timming with a colour wheel, maybe u need to elaberate with this rainbow efect on a lcd because ive never seen it in my life.

Trev

[mathias]

what about the blue spectrum

I´m sending in white light into the prism from the lamps, if that is what you mean. If the rainbow effect is not a problem than this thing will be even simpler, angle the second lamp so the rays comes out in the same direction as the first.

[ace3000_1]

angle the second lamp so the rays comes out in the same direction as the first.

Thats all u need to do with using the 1 prisim

[slize]

what do you think about this?

the first prism has a rainbow effect on the white light, the second reveals this effect, so one white light ray comes out. the black second light hits the second prism at a negative angle so this should be reflected and goes into the first light ray...

so i have one out of two beams...

based on this site and paint shop

http://www.uni-leipzig.de/~stann/java/prisma.html

[ace3000_1]

Guys, im talking about using simple mirrored prisims here, its all u need, what prisims are u talking about? because u wont get a rainbow effect on a normal mirrored prisim.

Trev

[slize]

it's a normal prism, fully made out of glass...

but anyways, as i looked on my budget i decided to give the single 150W bulbed version a try, as i saw good results in the german diy forum where this guy claims to have a 70W MH bulb and got a picture bright enough on an acceptable size.

May be the 150W will be enough to lighten a 15" tft; i'll give it try...

P.S.: Did you receive my adress?

[ace3000_1]

heya slize ya i got it, im running out now to post it, btw i was talking about mirrored prisims, use those they are what we need for this aplication, the others will loose too much light.

Trev

[mathias]

Guys, im talking about using simple mirrored prisims here, its all u need, what prisims are u talking about? because u wont get a rainbow effect on a normal mirrored prisim.

What I can see the mirrorprism will not work as a light mixer, even with lenses, the result out of that is a beam that is double as wide as high. And that is logical, to mix two beam you have to place them over each other and that is only possible with semipermeable material.

Glassprism will not lose more light than a condensorlens, because a condensorlens is many small prisms.

[ace3000_1]

the result out of that is a beam that is double as wide as high.

Hows this so? u could make this double wide depending of the angle of your choice, but not double high, its the same as having 2 mirrors but because with a mirror the peak cant be together Beacuse of the thickness of the mirror) you use a mirrored prisim, you have the sharp peak at the front so there isnt a gap in the lights center, noticable by the human eye anyway. You will find mathias no projector will use your idea, its impractical and runs costs very high.

Trev