Condenser

[EtoH]

I've just recieved some parts for a projector from exclusive online but i forgot to get a condenser. So 1st off, do i need one for a 250w setup and an 8in lcd and what does it actually do?? i understand why a reflectors useful in making the use of the available light - whats the condenser do?

secondly, does anyone know where i can get hold of one in the uk? the shippings too much to get one part from exclusive online (i'm based in london)

thanks

mike

 

[Guy Grotke]

precondensor lens

You can project an image without it, but your image will be brighter if you use one. The light comes from your lamp & reflector in a very wide cone (limited by the reflector). A condensor lens will redirect all of that light into a much narrower cone, so most of that light will go to your condensor fresnel & LCD.

Condensor lenses are usually made from a heat-resistant glass, since they have to be placed close to the lamp. You might be able to find a lens with the same focal length and diameter from another supplier, but if it is not heat-resistant it may crack from uneven heating in your projector.

If you substitute another condensor lens with different focal length or diameter, you will have to make adjustments in the geometry of your projector. If it is too different, then you may not get any improvement in your brightness, at all. The easiest thing to do is just get the exclusiv lens. Maybe you can find somebody local who can add your lens to their order.

 

[Gizmotech]

If you look at modern headlights, (the so called projector headlights), they have a pcx condensor lens built in. It goes in front of the halogen bulb. I'm sure if it can take the heat from the halogen bulb, it should be ok for your projector. You might be able to get hold of these from your local scrapyard. Also while you're out there, you can get front surface mirrors from there as well, renault van mirrors are front surface.

 

[Dazzzla]

All of the projection headlights that I’ve seen contain an elliptical or parabolic reflector and an aspheric condenser lens, none that I’ve seen use a pcx lens.

DJ

 

[EtoH]

thanks for the replies. It turns out I had a condenser all along, i just didn't look hard enough in the packaging!

now i know what it does though can anyone tell me where they get those metal ring shaped holders that everyone seems to use to hold them in place?

thanks

Mike

 

[Guy Grotke]

rings for mounting lenses

Those are computer fan protectors, that have had the center parts cut out. You might find some at a place that recycles old PCs, dirt cheap. Or you can check around at the various online DIY projector stores. I seem to remember somebody had them.

 

[Mikey p]

This is what you need in the appropriate diameter for your condensor lens.
http://www.isellsurplus.com/product.asp?ID=9898&C=6&S=39