The the limiting dimension of the wall I'm projecting on to is 72 inches across (width). It is exactly 12 feet from the wall I want to mount the PJ, to the wall I want to project on. The PJ is strictly for HTPC so I would like to use a desktop LCD monitor with a DVI input. Size of the projector box is not really an issue. I would much rather have a large PJ box and pay less if you know what I mean. Are there any pros and cons to using a 15" vs a 17" vs a 19" other than the obvious size factor? Do you have any recommendations on what LCD to purchase? I just happen to have a 400 watt Metal Halide light from a previous project, so are they all created equal? What is the quality difference between the Pro lens and the regular lens? Sorry for all the noob questions, I'm just really excited to work on this.

Cliffnotes:
-Is it even possible to project 72" width from 12 feet?
-What size monitor is best if I'm willing to use a big LCD if it helps picture quality.
-What LCD do you recommend?
-Will a standard 400w Metal Halide grow light work?
-Pro lens or regular?

Thanks a bunch!

I'm pretty new here, but I'll take a stab at a few of these questions

For a 72" screen at 12' you will need a 6.9" monitor with the standard triplett and a 11.4" monitor with a pro triplett. Splits designs will give you a slightly larger picture. I would say a 10" LCD would be your best bet.

A grow light ballast might work but I think the bulb would be the wrong color.

you're gonna want to download dazzzla's focal calc. http://www.lumenlab.com/forums/index.php?showtopic=7912

Karlf is probably right about your bulb being the wrong color. you can always give it a shot and see if you are happy with the results. but, you want to shoot for 6500k color temp.

a lot of people are perfectly fine with the standard LL lens. I have used it for over a year and am just now starting a rebuild which includes the Pro. if money is an issue, get the standard. you can get very nice results with it, the pro is just even better.

if you are going with the standard triplet, you'll want a 15" or smaller LCD. if you use a bigger panel you'll have to get the pro fresnels (more money.) you can also get a ballast from hi direct if you want to save some money.

I thought I've read elsewhere that the standard lens would would with a 17" LCD as well. Am I wrong? I'm asking b/c that's how my plans are set up for now. If that doesn't work, I'll have to look for a 15" LCD.

I believe that the projection lens will work but you will need larger fresenels than those which come with the standard kit.

Right...I understood that the projection lens would work for a 17" LCD, but I would need to get larger fresnels. Like the ones at 3dlens.

Dude, at 12 feet with the standard triplett you would have a 177 inch screen. Even with the pro triplett you would have a 107 inch screen

Everybody thanks for all of the input. I really appreciate it! So if I buy a 17" and a Pro lens, what distance will the PJ need to be at for a 75" WIDTH? I think this translates to an 85" DIAGONAL but I've been wrong before! And what do the fresnel ratings mean?

As always, my over-eager nature has led me to purchase a 17" monitor and a Pro lens. What will I need in the way of fresnels?

Note: I want to thank everyone for their patience with questions you probably get everyday. I promise when I understand all of this, I will take up the reigns and answer questions in the beginner forum!

Pro lens, 17", you will want the LL pro fresnels. From there it becomes a pretty standard build process.

So I just buy the ones from the LL store? I don't have to worry about sizes?