Basement HT. What to use for Screen

**Zeiggie** · **05-21-09, 12:51 AM**

Once my wife saw a movie with my new (first) projector, she loved it. Now instead of trying to fit a theater into a family room where the focal point is a gas fireplace requiring a portable screen, I can build a dedicated home theater in our basement. First, here are the answers to the requested information.

Room dimensions: 17' x 21'
Seating distance: 10' - 12'
Lighting conditions: Will be mostly light controlled. Some ambient light.
Viewing habits: Mostly movies with minimal ambient light.
What projector: Epson 9300i - 1400x1050 - 1100:1 CR - 2500 ANSI Lumens - Normal Zoom Lens

Additional lighting info: Occasionally room lights and some sunlight in the room. Recessed lights will be installed, and possibly some low output down lights near the floor along the entrance wall. The recessed lights behind the main seating area will have a dimmer so they can be on for reading if desired while minimizing light hitting the screen.

Additional room info: The north wall will be the home for the projection screen. On the far left side of this wall will be the main entrance to the theater, with a walkway along the left wall. Near the back of the left wall is an 8' opening going into a game room. The game room has two large windows with sunlight streaming in during the afternoon and evening hours. The south wall has another large window but does not get any direct sunlight after early afternoon hours. The left wall has three doors in it. One to the back yard, one to a bedroom, and one to a bathroom. The north wall at all times is fairly dark, even in the middle of the day, so would make a decent theater. (When we built the house, I designed a room for a theater with no windows, but that room became a storage room and is full of shelves now) As I finish this room, I will put in room darkening shades on the south window, but I am not certain of what to do with the 8' opening into the game room. So, I would say that I do not have total light control here, but the ambient light on the screen wall should be fairly minimal once the theater is completed.

Screen Wall: The north wall has about 13.5' width for the screen and main speakers. My main speakers are a pair of Klipsch LaScalla's I bought new 20 years ago. They are still awesome speakers. However they are 3' tall, 2' wide and 2' deep. This essentially limits the practical area I can put a screen to around 9' wide. As a temporary screen and for a baseline reference I bought a sheet of Do-Able and mounted that to the wall. I am amazed by the performance of this board and the fact that I can get a bright image all the way to the side untill the image dissapears at 90 degrees to the side. I just cannot see any hot spotting or bad seating area. But I would like better black levels and contrast. (I need to calibrate the PJ still) Since the PJ is 4:3 I plan on a 4:3 screen but have been designing a way to have masks that will pull up / down to mask the overshoot and provide any desired aspect ratio.

Projector: I am extremely impressed with the Epson 9300i projector. I know that it is not a "True" HD projector, but it does display pixel perfect 720p if scaling is turned off with black borders all around. The projector is very bright. During the day, it projects an acceptably viewable image at 8' wide with the sun shining in the adjacent room and a bare 40 watt CFL hanging from the ceiling 10' from the screen. I would have to say that my impression is that the projected image in "Family Room" mode appears as bright as our 37" LCD TV, and slightly brighter than our 32" LCD TV, and the laptop screen I have been using as a signal source. I have been using this mode as the "Theater" mode has a blue push to it and I have not had time to calibrate the PJ yet.

Since I am essentially starting from scratch with my theater, I am looking for recomendations for the screen, but also have the flexability to do what is needed to create the desired results. I got some screen material samples from "build your own projection screen", but they are fairly small making it difficult to determine their capabilities. I am open to both a material screen and a painted screen.

P.S. - I found a local store that has 1-16 oz bottle AAA Aluminum fine. I have them putting it on Will Call for me so I can pick it up tomorrow since I figure that I will at least try a panel of Black Widow. I tried the black back side of one screen sample, and suprisingly this did not affect the whites as much as I expected, so I am certain that a grey fabric or BW painted screen would both work well.

Thanks in advance for any assistance or recomendations. - Z

**Harpmaker** · **05-21-09, 01:29 AM**

Hi Z,

PJCentral has a screen calculator for your PJ that you might like to play with at http://www.projectorcentral.com/Epso...ulator-pro.htm, you will have to know which lens you have for best results.

That PJ is so bright at the screen size you are using (I assume a 4x8 foot sheet) that you could go with a VERY dark mix (darker than any I have tried) and still get a good image. The darker the screen, the better the contrast.

If I were in your position, I think I would get a 4x8 foot sheet of 1/8" hardboard and simply try various shades of neutral gray paint either using Valspar Ultra Premium Enamel or Behr #1850 paint. With around 100 fL. of screen brightness you may not have to worry about adding any reflective agents such as AAA-F.

**mechman** · **05-21-09, 09:58 AM**

Quote:

Harpmaker wrote:

With around 100 fL. of screen brightness you may not have to worry about adding any reflective agents such as AAA-F.

100fL?!?!?

I'll second what Harp says!

**Zeiggie** · **05-21-09, 11:22 AM**

Quote:

Harpmaker wrote:

Hi Z,

PJCentral has a screen calculator for your PJ that you might like to play with at http://www.projectorcentral.com/Epso...ulator-pro.htm, you will have to know which lens you have for best results.

That PJ is so bright at the screen size you are using (I assume a 4x8 foot sheet) that you could go with a VERY dark mix (darker than any I have tried) and still get a good image. The darker the screen, the better the contrast.

If I were in your position, I think I would get a 4x8 foot sheet of 1/8" hardboard and simply try various shades of neutral gray paint either using Valspar Ultra Premium Enamel or Behr #1850 paint. With around 100 fL. of screen brightness you may not have to worry about adding any reflective agents such as AAA-F.

I have spent quite a bit of time with the calculator at Projector Central. With an 8' wide 4:3 image (120") with the standard zoom lens I have at about 15' throw, using "Theater" mode, I have 26fl at the screen. If I zoom out or move the projector closer so the image height is 4', and use the "Family Room" mode (or "Presentation" on Projector Central) then I have 117fl at the screen. In this mode, with sunlight through the windows and no curtains (yet), the image on the Do-Able board appears brighter than any of our LCD TV's upstairs. I do plan on getting some grey screen material for a portable outdoor screen for movies at a family reunion we are having the end of July.

So far, I have tried the material samples I recieved from "Build your own projection screen". When holding up the grey materials, my wife says that the whites fade out too much. I even tried the black on the back side and the whites dimmed a bit but still looked very good to me, but the blacks were inky black and the colors popped. With calibration and not having the Do-Able board to compare it to, I was figuring that I could go with a darker grey like the black widow N7.5 to improve the blacks, but would need to keep the reflective agents in the paint to help the whites for the WAF. I am not dead set on this, but I do need to limit the purchase of materials or paint to a single shot. I am already getting asked why I want to use anything other than the Do-Able, but I plan on a 4:3 screen with moveable horizontal masking to maintain a wider screen width while adjusting the height and do not want a horizontal seam if I went taller than 4' for the 4:3 viewing we have with most of our DVD's.

With regards to screen size, I have tried projecting movies on the Do-Able board between 6' wide and 8' wide. At the smaller image size, sitting about 10' from the screen, I felt that the experience was not quite as immersive as going to the cinema. At 8' wide, I could start to see the screen door effect of the projector about 4 feet away from the screen. So I was figuring that I would definately go wider than 6' on the screen, and possibly a bit wider than 8', but I am limited to about a 9 or 9.5' wide screen. What would be the recommended or "ideal" width at a 10-12' seating distance. I believe I read somewhere that a 30 degree view was ideal, but I am just learning here.

Once again. Thanks in advance for everyones help. - Z

**Zeiggie** · **05-21-09, 11:34 AM**

With regards to the Epson 9300i projector. I am very suprised by the lack of information on the internet about this model. It was a professional or venu projector sold between 2004 and 2006, but I cannot find any reviews or any information other than the specifications like that on Projector Central. From my experience and comparing it to those I have viewed at the brick and mortar stores, it performs as well, and better than many of the less expensive (<$1500) projectors I have looked at. Currently you can buy this for $600 on clearance directly from Epson with a 2 year warranty. The lens is an additional $250, so for $850 (a 10% off coupon is on their site right now too, plus free shipping), you have an excelent performing projector with 2500 lumens and a 7000 hour lamp.

Is there anyone else out there who has used this projector in a home theater? - Z

**Harpmaker** · **05-21-09, 01:16 PM**

Sorry Z, my bad; I forgot to set the calculator to 'video' mode. I also used a screen height of 48 inches, this is why I had the fL. so high.

At 26 fL. at the screen Black Widow would be a good choice. In my opinion, you could go even darker, but no testing has been done along that line since most PJ's for HT use tend to be much dimmer than the one you have.

If I'm reading this right, you were comparing gray screens directly against the white Do-Able. This is a no-no. The white screen will always appear to have the brightest whites and the gray screen will always have the best blacks. Which one has the best colors is a personal choice. When the bright white reference of the white screen is removed, the brain will see "white" images (snow, clothing etc.) as white as long as the screen brightness isn't too low (not a problem for you

).

If you are thinking of painting your own screen I would recommend BW. Others will have to jump in here with commercial screen recommendations.

As for the "ideal" seating distance, I can't seem to remember these formulae. Perhaps another member will jump in with these figures and save the day.

**Zeiggie** · **05-21-09, 03:15 PM**

No Problem. Yes, I was holding up the screen samples up against the Do-Able board. In my mind I was able to disconnect from the differences in white levels and realize that I would calibrate the projector to what ever screen I end up using. What I was looking at was the white on the sample and the colors on the sample. Since the samples were small (only a few inches) I moved it around the screen to check whites, colors and blacks. Even with the black surface on the back side of some of the samples, the whites were still very bright, but I do not think I could get away with a completly black screen.

O.K. So I will try out Black Widow. I have looked through several threads here and on other boards about black widow, and I am a little bit confused for the proper mixture. I believe that I need some AAA Aluminum fine (just bought a 16 oz bottle locally during lunch). With the AAA, I need to mix that with Bermuda Beige or Bare Beige in a 1:4 ratio. I would imagine that it would not matter what measuring instrument I used as long as the proportions were 1 part AAA to 4 parts Beige. But what base color is best? I drive near a Home Depot and a Lowes daily on my way to work.

Can Black Widow be painted over a cloth screen, or does it have to be a solid substrate. I am asking because I am thinking of going with a 4:3 screen 8' wide and 6' tall. If I use Do-Able as the substrate, I would end up with a seam somewhere that would be hard to conceal. I could paint the sheetrock wall, but the design I am coming up with for the automatic masks top and bottom of the screen need to have part of the mask and cables going behind the screen, so I am thinking that a cloth screen would be the ticket - If this can be painted on black out cloth or even the matte white projection screen material sold online.

Once again, thank you everyone for your assistance - Z

**Zeiggie** · **05-21-09, 03:19 PM**

Quote:

mechman wrote:

100fL?!?!?

I'll second what Harp says!

Oops. that was a mixup. The correct number should be 26fL. - Z

Mechman - At 26fL with the above viewing conditions, do you also recommend the BW, or another surface?

Thank you very much - Z

**Harpmaker** · **05-21-09, 07:26 PM**

Black Widow is a binary mix, just two paints are involved. We recommend Valspar Ultra Premium Enamel tinted to match PPG Bermuda Beige #427-2. You should be able to simply ask Lowe's paint department to match that exact brand, name and number and get good results. Home Depot's Behr #1850 paint tinted to match the same PPG Bermuda Beige is also fine, but people seem to have had more problems getting a color match there.

The ratio is 4:1 Bermuda Beige to Auto Air Aluminum (fine). The reddish-orange of the BB counters the blueness of the AAA-F and the result is a VERY neutral gray mix with a Munsell Gray of about N7.5 (N10 is pure white, N0 is pure black). I think PPG Bare Beige would work, but the official formula uses PPG Bermuda Beige.

It doesn't matter what you measure your paints with as long as it is reasonably accurate. It is very important to mix the two paints together well. The squirrel cage type paint stirrers that fit into a hand drill work great.

Kilz2 is the standard primer used, but I find that I'm liking Kilz Premium these days - but that's just me.

As for the amount of paint it will take to paint your screen, I recommend 1 fluid ounce of paint mix per square foot of screen surface. It is always better to have a bit too much than a bit too little.

BW can be rolled, but spraying with HVLP, if possible, is better IMO.

BW can be treated as if it were regular latex house paint. Anything that can be painted with latex paint can be painted with BW. BOC (black out cloth) has been painted in the past, but it needs to be stretched on it's frame first. When using cloth, be sure the surface is the same texture over the whole surface. The aluminum in BW will show texture differences.

As for painting projection screen material; some have done it, but unless both sides of the screen are painted (the rear of the screen doesn't need to be painted with BW, just a similar latex paint) curling can be a problem as the paint dries - or so I have read.

**mechman** · **05-21-09, 07:28 PM**

Black Widow would do fine with 26fL. You've still got a lot of headroom once the bulb ages/dims.

**Zeiggie** · **05-21-09, 10:22 PM**

One more question I have. I need to make two screens. One will be stretched over a frame and permanently mounted. The second screen will be a portable screen to be used while camping and outdoors. For the outdoor screen I was thinking of sewing pockets top and bottom to insert a 1" conduit in the top, then a 3" pvc pipe on the bottom. The top pipe would be hung on hooks and the 3" pipe would weigh down the screen. This could be hung on the side of the house, or our travel trailer. For transport, the screen would be rolled up around the 3" pipe to prevent creases etc. The smaller pipe could be slid into the larger pipe. I have read that you can roll up painted cloth if using the right base paint, and a reference to a Behr exterior latex as staying flexible, but not the specific base paint. I will get the Valspar Ultra Premium Enamel for the permanent screen, but can get a second base paint for the roll up screen. Do you have any recomendations for a base paint in this situation, or know which Behr exterior paint to use? Remembering that a perfect neutrality is not required for this screen.

Believe me, I really appreciate all of your time to answer my questions. Thanks - Z

**Harpmaker** · **05-22-09, 01:50 AM**

I have been tempted to build a portable screen such as you describe, but I just haven't found the time. From what I have read of others experiments there are still problems with such a screen curling at the vertical edges after a short time in use. This is why many new commercial roll-up (or pull-down) screens are "tab tensioned" on those edges.

Just pulling from memory, I think those building such screens are now advocating making the screen a bit wider than needed for the projected aspect ratio, that way the edges can curl or distort without it affecting the actual area where the movie is seen.

A outdoor portable screen is where I would start looking closer at commercial products. Lots of interesting stuff at http://www.backyardtheater.com/. Of special note is the inflatable screen sold by Wal-Mart for $169 http://www.walmart.com/catalog/produ...36122316697820, unfortunately, it's a 16:9 AR.

The exterior paint I have seen most recommended for making an outdoor screen is Behr #4850 which is the exterior version of their #1850. A similar paint from Lowe's is Valspar Duramax flat. Both are exterior latex enamels.

**NegativeEntropy** · **05-22-09, 08:15 AM**

Zeiggie,

Earlier you asked about the standards for screen size.

Screen width:
THX recommends 36 degrees from the back row for cinema, and no more than 40 degrees for an HDTV.

SMPTE says a minimum of 30 degrees for theaters.

Since brightness is not an issue for you, I say shoot for the 36.

I'm aiming for 36 in my planning, as long as the SDE/pixel structure is not visible from that distance. With HD resolutions this should not be an issue (barring very large spacing between "rows" of seating in your HT).

Remember to consider vertical angle (angle from eyes to top of screen). 15 degrees max is recommended here by THX for HDTVs. SMPTE says 35 degrees max for the front row in a theater.

**Zeiggie** · **05-22-09, 11:20 AM**

Quote:

NegativeEntropy wrote:

Zeiggie,
Screen width:
THX recommends 36 degrees from the back row for cinema, and no more than 40 degrees for an HDTV.

SMPTE says a minimum of 30 degrees for theaters.

Remember to consider vertical angle (angle from eyes to top of screen). 15 degrees max is recommended here by THX for HDTVs. SMPTE says 35 degrees max for the front row in a theater.

Awesome Negative Entropy. Thank you for those figures. If I remember my trig correctly, then at the 12' seating distance i will have, this would result in the following ...

Horizontal viewing angle
36 degree viewing cone = ~94" screen width (7'-10")
40 degree viewing cone = ~104" screen width (8'-10")

Vertical angle to top of screen
15 degrees above viewers eyes = ~38" (For those sitting down)
35 degrees above viewers eyes = ~91" (For when lounging on the floor)

From these figures, it sounds like the room I have to build the theater in is just about perfect. I will end up with about a 9' wide area for the screen. (13' wide wall, with 4' taken up with speakers on the sides of the screen.) If I build the screen with a 4" border, I am left with 8'-4" (or 100") clear for the screen - Dead center of the calculated viewing cones recomended by THX. When seated on the couch, the viewers eyes will be about 40"-48" height. So, (40" to 48") + 38" = 78" to 86" max height to the top of the screen.

Using these figures, I will plan on a 100" wide 4:3 screen with adjustable masks for 16:9 and 2.35:1 aspect ratios.

4:3 = 100" wide, 75" tall, 125" diagonal, (84" height for top of screen)
16:9 = 100" wide, 56" tall, 115" diagonal, (74" height for top of screen)
2.35:1 = 100" wide, 43" tall, 109" diagonal, (68" height for top of screen)

This puts the top of the screen within the limits you specified for THX for those seated.

Up until now, I have been designing everything by gut instinct. I am glad to see that I have not been too far off from ideal. Thank you very much for all of your help. - Z

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