# Projector screen and projection calculator

Discussion in 'Beginners, General Questions' started by jonnyMa, Apr 10, 2006.

1. ### jonnyMa Agent

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Im gonna attempt to build my own projector screen but I have a few questions. Im probably gonna go for the panny ae900. Im using the projection calculator on projector central and the projector is gonna be about 14 foot from the screen. So I set the throw disatnce to 14 foot and it gives a sceen size of 70 inch diagnol, 61 inches wide and a height of 34 inches. But what exactly does this mean? Is this the optimum screen size for that throw distance? Is that the size I should build the screen. I was hoping to have a bigger screen then that. Could anyone shed some light on this or even point me in the direction of somewhere that explains the ins and outs of projector screens (Iv already had a look to no avail). Thanks.

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Basically, a projector (without a zoom lense) throws a given image at a given distance. The further you move back, the bigger the image (of course, the further you move back, the dimmer the image).

Think of it like a flashlight: as you move the actual light away from the wall- the size of the spot gets bigger...

The numbers you got from the calculator is not the "ideal" - it is the size of image this particular until will create when placed that far from the screen. Some projectors have zoom lenses which allow you to vary the image size a little-- but in most cases the size you're getting from the calc is the exact size the image will be when placed at that throw distance.

Hope that helps.

\V

3. ### Jim Mcc Producer

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Jonny, their calculator shows a minimum and maximum screen size from the throw distance you choose. Obviously, that size is the minimum without using zoom. The Pan. 900 has a very large zoom range, which makes it very versatile for installation.

4. ### jonnyMa Agent

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So is it a matter of just waiting till I get the projector and then just seeing what size suits the room best before I build the screen.

Also im sure a while back I saw something somewhere that gives an ideal screen size for a given seating distance from a screen. Does this ring a bell with anyone? Thanks

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Here's one - link. I sit about 11.5' from my 103" screen.

-Robert

6. ### Brian Osborne Stunt Coordinator

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I did my own screen. I build mine right onto the wall. Check out the link below to get to the pics. I set mine back in the wall and at the advise of someone else on the boards I painted the whole wall with the screen paint. I'm very happy I did. I've seen installs with a screen frame and a set size screen and I didn't like the frame look.
Check out www.DIYtheatre.com
I used their product for my screen. I couldn't be happier with the result.
Another one to look as is www.goosystems.com
both are very similar products.
I wouldn't trust the calculator on any site except for the manufacturers web site. Look at the size chart for the specific projector you are looking to buy.
http://www2.panasonic.com/webapp/wcs...s&displayTab=R
The specification sheet will show you the throw range for your projector. Works out to be between .851 to .416. Take this number multiplied by your distance to get your screen size range. At 14' you have screen size option of between 70" and 143" This projector has a great zoom so you should be able to place it wherever it should be to be out of the way.
Before building anything, I'd look at the projector installed and see what size works best for you.
Good Luck to you!

7. ### jonnyMa Agent

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Heres the thing about seating distance from the screen I was talking about http://electronics.howstuffworks.com...ing-guide1.htm

It will be almost exlusively dvd and satellite and the seating position will be about 12 feet from the screen so would 72inhces sound good to people? Im just worried about going too big and not being able to change it. but at the same time I want to go as big as I can Anyone any suggestions on screen size?

Also has anyone built a projector screen from online instructions that turned out well? if so could you post the link. Thanks.

8. ### Brian Osborne Stunt Coordinator

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Having worked with art supplies for years I'm sure I could get really close to the materials used and get a very similar result from materials in your local art store. However, I did price this out because I was curious. Using quality materials such as Golden polymer acrylics, Golden iridescent medium and such the price was actually higher using those supplies. I've got the breakdown at home if you are interested in the materials I found to be closest to DIYtheatre.com. For less than \$250 you can buy the kit with everything you need including the high quality rollers that don't shed.
As for size, don't be scared of it. My screen is 90" and primary viewing is about 8' from the screen. Yes, I can, on static light images see a small amount of screen door. But, while watching movies, it's not noticeable. Only when I use my computer do I see it.
I wouldn't try to stretch anything yourself for a DIY screen. doing this without wrinkles is tough at this size and sag over the years will be making you wish you hadn't done it. Using a sheet of drywall, MDF, or other such preflat surface will get your best DIY result.
Back to your question about optimal size, there really isn't one. The image is changed optically so there really shouldn't be any quality loss by using the zoom.

9. ### Jim Mcc Producer

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A 72" screen is TOO SMALL with a 12' seating distance and a 720p projector. With a 720p projector like the Pan. 900, the rule of thumb is to sit 1.5X screen width from the screen. That equals a screen size of about 110" diagonal(54"X96").

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I didn't use instructions. I looked at a lot of DIY screens, took the parts that worked for me and combined them to may my own. I used 1x3's from Lowes for the frame, blackout cloth for the material and door casing to make a decorative frame. I have a few pictures of the build process if that will be helpful and can answer any questions in detail.

-Robert

11. ### jonnyMa Agent

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Ok thanks a lot guys, thats cleared a lot up. Its pretty overwhelming for a newbie this HT game

P.s. I would like to see those pictures Robert if its no trouble.

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The frame is a simple 16x9 format with bracing. The two braces are set back about 2mm from the front. I did this by putting some thin washers under the metal T brackets that hold the braces to the outer frame. I mounted it to the wall with what I've always called a "museum mount". There's a long board with a 45 degree angle cut on top screwed into the wall. I have another long board with a 45 degree angle cut screwed into the top of the screen frame. I hook the two together and it allows me to slide the screen back and forth to center it on the wall. Everything is visible here. (please ignore the hot sauce stain on the t-shirt)

I stretched blackout cloth over this frame and stapled it with an air staple gun. A manual one will work but I went through about 200 staples over this whole screen. Just stretch a section tight and put in two staples. Top, bottom, left, right, repeat.

Then I build a frame out of door casing and a decorative piece in each corner. Not sure what they are called but they are in the next picture. Painted it flat black and used a brad nailer (air stapler/nailer was \$18 well spent). pic of corner
pic of door casing
finished product framed in curtains

If you have specific questions, I'll do my best to answer them. I used a table saw, compound miter saw, air stapler/nailer and paint brush. Took about 4 hours total to build not counting the paint drying.

-Robert

13. ### jonnyMa Agent

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Great job Robert. Thats exactly the sort of thing im looking to do. Like the frame as well, adds a nice touch of class. Thanks for the help Robert and anyone else who helped.

14. ### DaveD' Stunt Coordinator

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Jonny, I'd recommend waiting to get the projector before building your screen. Get a feel for the image and then figure out what size YOU like from your viewing distance. An ideal size to one person isn't to another. I personally have the ae900u with a 96" screen and seating about 11' back.

15. ### Rennie Cowan Agent

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**I did my own screen. I build mine right onto the wall.**

That is the way to go. You would do best to adjust your surroundings for this new projector. Some people have painted walls white (as a substitute for a screen).

16. ### Joel...Lane Second Unit

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I just saw a program on TLC or the HG channel and a professional installer built a custom home theatre for under 15K.

They used the ScreenGoo and it looked very good. You really couldn't tell it wasn't a real screen.

The screen shots they showed also looked very detailed.

I'm considering using the Goo when I build my screen.

Good luck!