I am about to build my PJ now, going for the Haas-style. But I'm not 100% sure of the measurements.

My setup:

Pro Triplet (FL = 500)

220mm and 650mm fresnel

eBallast, 400W

T15 Bulb, 400W

17" LCD-panel

I've read that the split-configuration is the best. So that's what I'm going to use.

I only have a 2meters x 2meters big screen. But I want to make the PJ-box ass short as possible. And as far as I understand. The smaller you want the screen, the closer the PJ need to be the screen and the FL will get longer. (The box will get longer). Is this right?

So, to get a good picture on a 2meter x 2 meter screen, the FL from the 650mm lense to the Pro Triplet must be around 610mm? And the PJ needs to be around 2800mm from the screen?

Is there a diagram for this? I have searched and read all over the forum, but I can't find anything that fits my setup 100%. Since I'm a little confused about the screen size

I tried using the Focal Calc and this is what it says, if I understood it correctly.

And the most important question: In the Focal Calc, is the size of the screen diagonal og is it the height?

Need some help. Thanks

Diagonal.

If you use height, it outputs, height. Diagonal -> diagonal.

It just uses the scaling (magnification) factor of the lenses to give the sizes.

Good luck with your build

That means this will be my measurements?

keep in mind that the LCD isn't perfectly square. If you are dead set on 2m wide x 2m tall as maximums then you will be limited by width, measure the LCD width (in inches) and set the screen to 2000 mm and those will be the measurements (approximately exact).....always allow adjustment of everything.

Why? That means I won't be able to use the whole screen. That means I only get a 80" screen, while I could have had 111". No point in doing that, is it?. I want to use the whole screen

The projector justs magnifies the size of the LCD, the aspect ratio of the LCD isn't 1:1. The diagonal size you just calculated for is based on a 1:1 aspect ratio. Most computers are 4:3 (width to height) or 5:4....or somewhere close to those numbers. So you need to take the max width of the screen given a 2m x 2m screen (material) and measure the width of the LCD, then get the focal lengths (distance from screen to triplet and triplet to LCD) to have accurate numbers.

Ah, now I understand what you mean

Hmm... That was no good. And the PJ needs to stay very close to the scrren. Like 2,8 meters

But do I need to decrease the screen from 2828mm to 2000mm? Couldn't I just decrease it a littlebit?

The dimension of the active screen at LCD is 337.92 x 270.336 mm

So put in 337.9 mm/25.4 mm = 13.3" for the LCD size, and 2000mm for the screen size. See what that gives as a distance, it may be more than 2.8, if it is then you either need to increase the split distance on the LCD/fresnel split, or be willing to accept a smaller projected image.

Anyways, does that make much of a difference on the dimensions of the box itself?

From what I can see, the box only increases it's length by 4,5cm from a 80" screen and a 120" screen. Correct? And if I add some sort of lense-adjustment, I can easily adjust it if I want a bigger screen later?

By doing that the distance became 3,37meters

Hmm... OK, that means the inner dimensions are:

(220mm + 15mm + 20mm + 586mm + (30mm for lens adjust?)) + around 100mm with free space under the reflector = 971mm

And when you use the Focal Calc. Is 586mm the distance from the 650mm Fresnel to the middle of the Triplet Lense or at the rear end?

its from the middle i beilieve or at least thats the way it looks

Okay, thanks.
Anyways.. I have started on the box now. Gonna start cutting soon =)