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Discussion Starter · #1 ·
This is my first PJ setup project, so I'm just learning... it's all new to me. We currently have a 50" plasma which is just too dang small. You know it.


Our HT/living room is 23'8" long x 15ft wide x 12ft vaulted (11ft up to a log beam that runs the length). Even in summer the outside light is very subdued - usually too dark to read because of a long deck roof attached to the outside wall. We have window coverings (blinds) but rarely have need to use them.


All along one side is open to a dining & kitchen area where we still want to see the screen - somewhat, so the viewing angle needs to account for that (prime seating area is of course in the living room).


I want to have the PJ on the back wall up around 7ft on a shelf. My reasoning for the PJ location is 1) wiring convenience with my AV console stack immediately below it, 2) move any fan noise to the rear, and 3)aesthetics - not having a PJ hanging over our heads in the living room.


Our current seating is 12ft from the wall where I want to put a 120" (diag) screen, but we will be moving the seating back to 15ft from the screen. For the screen we want a motorized drop. Not sure of what gain rating (I'm thinking something between 1-2), screen color and I'm assuming 16x9 is the way to go (we view only widescreen format movies & broadcast (HD)? When do you choose a 2.35:1?


I'm considering a JVC RS40/X3, which has 1300 ansi lumens, a 2.0 lens and 3D. It's a pretty big unit, so I anticipate 20" depth from the back wall to the front of the lens, leaving close to a 22ft throw distance.


Can you help? The projector calculator doesn't have this PJ listed for their widget.


Is using a decent PJ like the RS40 recommended for fulltime TV use or is that going to kill it?
 

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The projector calculator for prior jvc models should be fairly close. 22' should work though. Noise shouldn't be an issue, I have an RS2 six feet from my head and it's not too loud You probably want a low gain screen if you need off-axis viewing from the dining and kitchen area. Post a floor plan and a few pics if you can.
 

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Discussion Starter · #3 ·














For scale reference, the couches shown are 7ft wide each. The pj screen shown is 105" x 58", but we will most likely get a motorized drop and mount that case up at around 8ft".
 

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Quote:
Originally Posted by coolplazma /forum/post/19628663



When do you choose a 2.35:1?

If you're bothered by black bars on some movies (that were shot in wider aspect ratio) you'd use a 2.35 screen. The tradeoff is that normal 16:9 content won't fill the full width of the screen - black bars on the sides instead. There's a topic for 2.35 - don't want to derail this thread!


Quote:
Originally Posted by coolplazma /forum/post/19628663



Is using a decent PJ like the RS40 recommended for fulltime TV use or is that going to kill it?

Daily use won't kill it, but be prepared to buy lamps fairly often. You could set up your screen to drop down in front of the LCD for movies, sports and worthwhile TV and just use the LCD run of the mill mindless drek.


Keep in mind that any ambient light will really hose the picture. If something is worth watching on a big projection screen, it's worth pulling a few curtains and killing the lights.
 

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Discussion Starter · #5 ·
Using the ProjectorCentral - Calculator Pro, I tried the RS35 as a substitute for not having a RS40 selection. Valid?


Setting the throw to 22ft and diag screen of 120", this results is a zoom of 1.09x. Optimal?


Upped the gain to 2.0 to get FL 28 (I chose this as a somewhat arbitrary value to fall within the "room with ambient light" range). Correct gain value? As mentioned above, we don't get harsh, direct light from the windows since there is a substantial deck roof outside which makes the inside quite subdude. What is the best value (quality & reasonable price) "+gain" screen that still has a good viewing angle?
 

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You probably won't be able to go with a screen gain about 1.5 without it having too limited a viewing angle. Higher screen gain (i.g., greater than 1.0) is achieved by focusing the reflected light into a narrower cone, so it's a trade off. In any case most screens with gains above 1.5 are more speciality products aimed at certain specific applications. Some of the most popular high gain screens are made by Dalite and it is any of their models that use their "High Power" screen material. This is offered in 2 versions with 2.4 and 2.8 peak gain but in order to get these gain values the projector must be mounted near eye-level (e.g. 50 inches above the floor) and the viewers must be located toward the centerline of the screen (due to the narrow viewing cone). Also in your case of have to use the projector's zoom for max. projector-to-screen throw distance, you will lose some of the light output from the projector. The 1300 lumens rating is for a too high 8500 deg. color temp and that mode is intended for 3D mode (where the 3D shutter glasses lose a lot of light). For normal 2D mode with a 6500 deg. color temperature the light output will be more like 900 to 1000 lumens and this is with a brand new bulb and with the zoom set for the shortest throw distance. With a just few hundred hours of use on the lamp with with the longer throw distance you need, the actual lumens will be more like 400 to 500, and I suggest that is what you need to be considering when deciding on a screen and the need for maximum light control in the room. It if were me I would consider mounting the projector using a ceiling mount and placing it toward the shortest throw distance for the selected screen size (for a 120" 16 x 9 screen would be just over 12 ft. from the front of the projector's lens to the screen. This would give max. lumens from the projector, but I realize that you may not be willing to consider that route with your high vaulted ceiling due to how it would look and perhaps also the complexity of getting power and signal cables to the projector.
 

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Discussion Starter · #8 ·

Quote:
Originally Posted by Pete /forum/post/19646530


Do you have enough lens shift to get the image down onto the screen?

Anticipated pj mount height was at around 7ft. With the screen bottom 24" from floor, the top of the screen display area (some 58" tall + the bottom mask & bar) should be near equal height to the pj. So I figured this should be within typical lens shift ranges.

Quote:
Originally Posted by Ron Jones /forum/post/19646485


You probably won't be able to go with a screen gain about 1.5 without it having too limited a viewing angle. Higher screen gain (i.g., greater than 1.0) is achieved by focusing the reflected light into a narrower cone, so it's a trade off. In any case most screens with gains above 1.5 are more speciality products aimed at certain specific applications. Some of the most popular high gain screens are made by Dalite and it is any of their models that use their "High Power" screen material. This is offered in 2 versions with 2.4 and 2.8 peak gain but in order to get these gain values the projector must be mounted near eye-level (e.g. 50 inches above the floor) and the viewers must be located toward the centerline of the screen (due to the narrow viewing cone). Also in your case of have to use the projector's zoom for max. projector-to-screen throw distance, you will lose some of the light output from the projector. The 1300 lumens rating is for a too high 8500 deg. color temp and that mode is intended for 3D mode (where the 3D shutter glasses lose a lot of light). For normal 2D mode with a 6500 deg. color temperature the light output will be more like 900 to 1000 lumens and this is with a brand new bulb and with the zoom set for the shortest throw distance. With a just few hundred hours of use on the lamp with with the longer throw distance you need, the actual lumens will be more like 400 to 500, and I suggest that is what you need to be considering when deciding on a screen and the need for maximum light control in the room. It if were me I would consider mounting the projector using a ceiling mount and placing it toward the shortest throw distance for the selected screen size (for a 120" 16 x 9 screen would be just over 12 ft. from the front of the projector's lens to the screen. This would give max. lumens from the projector, but I realize that you may not be willing to consider that route with your high vaulted ceiling due to how it would look and perhaps also the complexity of getting power and signal cables to the projector.

As far as pj light reflection to the viewer eye (pj -> screen -> viewer), I always thought this was something of a bankshot (billards speak) and otherwise not necessary to have the pj at eye level (I mean, how the hell do you mount a pj at eye level and not have the fan stuck in your ear?). Otherwise, yes - having the pj dangling in the middle of the living room, some 4 ft from the vault beam is probably not the asthetics we want.


For my application, Dalite HP seemed a bit too high a gain (more than I needed) and too narrow a view angle. Even at the brightest times, the room is too dark to read so when I started this project thinking it would be an easy task. ha. Well, now I am considering leaving the 50" plasma wall mounted and then dropping this pj screen in front for cinema/game time and saving the pj bulb life - though my wife won't get her wall art in place of the plasma
It's a tougher sell when trying to justify having both a pj & plasma taking up her precious wall space. A tech upside to this double setup is that I'd probably hang the screen off the wall using extention brackets, reducing the throw by maybe a foot (to 21ft), and pushing the pj away from the back wall another 6" gets me to 20.5ft throw which sets the zoom at 1.18 and a fairly acceptable 21FL with a 1.5 gain screen.


As far as good buys for 1.5 gain screens and >= 50 degree view angle, maybe something like the new Draper M2500 material is worth a look (I posted some M2500 product update info at http://www.avsforum.com/avs-vb/showthread.php?t=986832 ). What's the deal with the following screen size differences? Which do most people use? I would think the 1st one below is the more usual size, though I find it odd that the diagonal of 119" with a 58" height is less than the 2nd diagonal of 120" with a 56" height (same width on both screens). What am I missing here?

16:9 HDTV Format 119" 58" x 104"

1.85:1 WideScreen Format 120" 56" x 104"
 
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