CurtPalme.com Home Theater Forum

joatmon · Joined: 17 Mar 2009 Posts: 127 Location: Ottawa, Ontario

My Barco 708 (Runco with colored lenses) has a 113.5" projection distance for a 84" wide 16:9 screen. How similar is that to other compact projectors?

I'm limited by ductwork... just curious what else has a hope in h3ll of fitting years from now if (when?) I grow tired of my little toy. Smile

Reason for asking is that I'm at the framing / electrical stage of my dedicated HT room and now would be a great time to strategically place rigid mounting points behind the drywall were I could expect to have to place future projectors.

Beasts like a 1209 have no hope of ever fitting in this room, and anything much beyond 84" wide screens are as well.

E.

paw · Joined: 08 Mar 2006 Posts: 1176 Location: Arvada, CO

HMMM!!

DWIN's are pretty small.

Maybe a Sony D50 but that's probably a step down. Just checked, it's bigger

NEC PG, PG+ an PG Xtra are just a little larger. XGs just a little bigger but noiser.

Marquees are taller.

Here's a link to PJ specs. The physical sizes are at the bottom of each page

http://curtpalme.com/PJSpecs.shtm

Here's a link to PJ ranking.

http://curtpalme.com/Projector_Rankings.shtm

The colored lenses are a big plus. Really helps with the colors. I'd recommend looking for another PJ with those.

If you're open to digitals, quite a few of them have lens shift capabilities. That could resolve the ductwork issue. Plus them have zoom capability.

ecrabb · Posted: Wed Jan 20, 2010 9:47 pm Post subject:

Most CRT projectors are going to be at least the throw you have and longer for the same screen size. That's going to be true of most digitals, too... In fact, take a projector like the Panasonic AE4000... With a 113" throw, at the widest zoom setting, you'd just barely squeak by with the 84" wide screen. But, don't forget, that you can probably get at least a couple more feet of throw just because the projector is so much smaller. Just sliding the digital back the nearly 2' extra room that the 708 takes up gets to about 96"/110" diagonal - again at the projectors widest setting.

You can use the calculator at ProjectorCentral to pick some popular models and see how the pic size works with those projectors, and play around with different throw distances.

http://www.projectorcentral.com

SC

TheVerge · Joined: 19 Jul 2009 Posts: 928

joatmon · Joined: 17 Mar 2009 Posts: 127 Location: Ottawa, Ontario

cmjohnson · Joined: 03 Apr 2006 Posts: 5180 Location: Buried under G90s

It's safe to say that the general average throw ratio for CRT projectors is in the general range of 1.5 to 1. If the projector is 15 feet from the screen, the image will be 10 feet wide. If it's 12 feet from the screen, the image is 8 feet wide. Or 9 and 6. Or 6 and 4.

You get the idea.

Incidentally, you have that backwards: A Barco is not a Runco. Some Runcos are rebadged Barcos. Barco is an actual manufacturer,
Runco just rebadged Barcos and other brands and changed a few minor details.

Your Barco is a Barco.

CJ

ecrabb · Posted: Thu Jan 21, 2010 7:35 pm Post subject:

CJ,

It wasn't clear, but I think he knows his Runco is a rebadged Barco... I think his sentence "My Barco 708 (Runco with colored lenses) has a 113.5" projection distance..." really meant "My Barco 708 (to be precise, it's a Runco, and it has colored lenses) has a 113.5" projection distance..."

Isn't the throw a lot closer to 1.2-1.3x? My G70 is about 120 from my 96" wide screen, so about 1.2x. I know the 9" machines with HD-10's are a foot or two longer because of the larger tube, so maybe 1.3-1.4x, right?

SC

cmjohnson · Joined: 03 Apr 2006 Posts: 5180 Location: Buried under G90s

Sorry, I had a typo there. 1.25, not 1.5.

Dropped the 2.

My own machine is 120 inches away from a 96" screen. 10 feet away for an 8 foot wide picture, right at 1.25 throw ratio.

CJ

joatmon · Joined: 17 Mar 2009 Posts: 127 Location: Ottawa, Ontario

VideoGrabber · Joined: 09 Apr 2006 Posts: 933 Location: Michigan

CJ, glad Steve caught you on that 1.5 to 1, because I was going to have to rip you a new one. Wink

SC wrote:
> Isn't the throw a lot closer to 1.2-1.3x? My G70 is about 120 from my 96" wide screen, so about 1.2x. <

120" to where on your G70? If you want to calculate ratios in any meaningful way, it has to be to the plane of the CRT faces. Not, e.g., to the front of the lenses.

> I know the 9" machines with HD-10's are a foot or two longer because of the larger tube, so maybe 1.3-1.4x, right? <

It depends on both the lenses and the lens/PJ combination. It ranges from 1.2-1.4x, with values from 1.2-1.3 most common. That's if you set things up for proper phosphor utilization. "Book" values are more commonly in the 1.3-1.4 range. On that Barco LENSE program, it's at 1.35x, which is probably a bit too far back. Lastly, it will also vary somewhat depending on whether you're setting up a 4x3 screen vs. a 16:9.

A tip to the OP, make sure you actually test your throw distance, because even though Barco provides a program that gives you what looks like precise recommended results, they're really only an approximation. Unless you want to waste as much as 8% of potential phosphor use, and wind up having to drive the tubes harder to get an equivalent amount of light output from them. So if you do wind up putting it a little too far back, the only way you'll have to compensate, and fit things on an 84" wide screen, will be to drop the image size on the tubes. (Or perhaps, move your screen out from the wall, if that's possible.)

You didn't list your room dimensions, but it sounds like you may have decided the 84" maximum (which is a good size for that PJ), is because you needed the longer dimension of the room for adequate throw distance. However, there are tricks that can get you extra throw in constrained situations. I.e., mounting your PJ vertically on the back wall, and using a first surface mirror to bounce the image to the screen, can give you more throw range and wider possibilities for screen sizes, that would otherwise not be possible. Being able to adjust the PJ's vertical position on slides also lets you trim the image width fairly easily. Just a thought.

joatmon · Joined: 17 Mar 2009 Posts: 127 Location: Ottawa, Ontario

Tim,

I will be installing vertically placed Unistrut so that I can slide the PJ as needed. Thanks for the tips and the point about maximizing the phosphor use.

I've attached some SketchUp drawings of the room (drawn to scale) with the PJ-to-screen relationship as recommended by Barco. The projector cannot move backwards any further unless I go under the ductwork (which technically could be done if needed by tilting the top of the screen to fix the projection angle).

It just occurred to me that I could do this a little backwards. I am starting out with a 5' by 12' sheet of Wilsonart, instead of making the PJ fit the screen I could make the screen fit the phosphor after placing the PJ where I want it. Can I assume it shouldn't be too far off of 84" SW?

I'm also thinking of moving the projector up higher than recommended, and compensating for it by tilting the bottom of the screen outwards a little. SketchUp tells me the screen angle is only 4.9 degrees.

The screen will be picture framed (not sure if that is the correct term) by building a structure around it to house and hide the LCR and SW speakers. Probably will include a small stage as well. With only 10.5' of wall, and the duct work where it is, the 84" screen width wasn't so much a matter of choice for me.