Hi Guys,

Im in the process of getting the things i need together to make up a projector. So far I have a 220mm condenser fresnel, a 650mm field fresnel, a 12" LCD and a Lens from a Hitachi PJ-TX100 that someone was throwing out. (I think the focal length of the lens is 35mm)

My understanding is that the frensel will focus the image down to the point. If the lens diameter is just outside the cone of light then the image will be projected correctly. I know that using such a small focal length will mean that the throw distance is greatly reduced.

It this correct?

As far as I can tell the lens has a adjustable zoom and focus but I am unsure if this will really help much in the end.

My plans are as follows:

Bulb - 220mm - Fresnel - 10mm - LCD - 20mm - Fresnel - then about 580 - 590mm to the lens. ( Thats if my math is correct).

My thought is that I should design the box around having a 500m pro triplet. Then if the commercial lens fails i have a backup.

Thanks

No it won't work.

A commercial projection lens is made with a FOV (field of view) just large enough for the LCD's it uses. In your case that would be a .7" lcd.

So it won't work for an LCD bigger than 1"

Why do I get the urge to just answer every question with "READ READ" now?

Thanks guys, I was holding out hope i could be a cheap ass and not buy a triplet lens. But oh well.

I have seen a few projection lenses on ebay go for less then 15 bucks cdn

LOL I am sure glad you posted that I started to feel bad about the topic I started.

Nothing wrong with asking about this but it has been covered many times before. If you look at the focal length it should have given you a clue.

Mind you seeing you got it for nothing then it dosen't really matter .... except you will have to get a different lense to use in a projector. Maybe it will look nice as a display piece in your home theatre area!