Hello,

I have just started to build my projector it will be 10.6 build with beseler triplet unsplit design with the 150w lamp with reflector and precondenser.

I am going to put the the 550 field fresnel 1 inch (25.4mm) from the lcd and the 220 2 2inches (50.8mm) from the 550.

My question is there much if any ajustment horizontally? or is this pretty much it? I am not sure if I need to have them able to move back and forth?

Mystic

Your fresnels may safely be made into a fixed cassette (fixed relative to one another) but you'll certainly want some flexibility in terms of other "horizontal" component movement. Two inches between them is fairly excessive but such a large spacing shouldn't be inherently deleterious to the best of my knowledge.

Edit: Allowing for some flexibilty in component placement is always the best scenario. At the very least you should do a mock-up using your intended component spacings before your final build.

Thanks for you response

What is the typical spacing distance inbetween the fresel? I was thinking of having the triplet & the light engine movable with the lcd being fixed but was not sure about the fresnel's

Paraphrasing member SupraGuy (refer to this post):

Regarding the distance between the fresnels in an unsplit configuration even a tiny offset of the fresnels along their centerlines - when they are very closely spaced - will result in artifacts appearing in your projection. I personally recommend an absolute minimum of 3mm for this gap. 10mm makes lens placement much simpler, with less need for precision.

For the distance between the LCD and fresnel, this is basically a coolant passageway using conventional design parameters. 15mm is plenty of space, could go as large as 20mm, but less than 10mm is inviting the grooves in the fresnel to project on the screen image, not to mention preventing adequate flow of air to cool the panel.

Hope that helps.

Thank you

Just beware that some of us have seen problems with an unsplit setup using the 10.6 screens. Leave yourself room in your design for a split setup because you may need to switch to it.

I used a 12mm piece of MDF with the fresnels each side when I was trying the unsplit setup. On a blank screen I could just see fresnel rings beginning to show in the corners.

oz brings up a vital point. It's crucial to do your homework prior to beginning a build as well as doing a mock-up.

Tastes vary wildly from person to person. When I was first getting my projector set up I was seeing some fresnel rings projecting onto my screen. When I stuck the LCD in and looked at an actual image I couldn't see the fresnel rings at all. I'd have been very happy to leave things as they were but still fiddled around to get rid of the rings. And my fiddling continues and probably will continue to some extent forever.

My point is some people would NEVER accept being able to see those projected rings. Others wouldn't be bothered at all. And you've got everything in between those two extremes.

You're building to satisfy yourself.