Is a Condenser Always Needed?

[Luca Brazzi]

Im planning on building a projector using a 7" lilliput and a 250 watt double ended MH bulb.

Is a Condenser necessary?

 

[Quin]

From what I gather its more benificial to use one on a 7" or smaller project, to minimise light loss. I expect it'd still work quite adequetly without, but perhaps a shorter 220mm rear fresnel focal length would be in order.

 

[dj_holmes]

check out my link 5.6" screen with ohp. i posted my progress during my pj experience and right at the end it screen shots of condenser and wow. it really helps to direct most of the light to a point. its does help. i repeat it does help. maximise your pj man. but i used a 150 hqi 250 will be tooooo much with condenser wooooooowwwww 😱 😱 😱 😀

 

[Luca Brazzi]

But Which Condenser Lens?

I see lots of people using an 80mm diameter with 89mm fl....

But I cant seem to find that one anywhere... I have seen some larger with longer focal lengths though...

Does it really matter?

 

[gazza]

also people say you can use both dcx lenses and pcx lenses has any one used a dcx lens