CurtPalme.com Home Theater Forum

whats6x7 · Joined: 04 Oct 2006 Posts: 5924

This will make some of you cringe. Sorry.

A little background first. 1 Month ago if I could have found an 800x600 LCD projector, 450 lumens (or so) with a 350:1 contrast ratio on eBay for $300 or less i would have bought it in a heart-beat. All I wanted was a 60"-70" screen to watch Babylon 5 (I'm a geek) on while I rode an excercise bike. Then I found CRTs and started drooling.

I bought a VPH-1020 for $157 shipped to play with but I've found someone local to buy it for $200. Now I have this 1272 that I was given and I'm trying to set it up.

Problem is, my office is 17'x13'. If I max the rasters an 80"x60" (which is still a little large) screen requires the front of the 1272 projector to be 102" away from the wall. Either way this puts the thing in the middle of the stinkin room. I don't want to mount it on the ceiling because . . .

a. I'm not that strong
b. I don't have a block and tackle
c. My wife is NO HELP when it comes to my toys
d. I want to have it on the floor where I can get to it easily.
e. I don't want to spend the money on a long VGA to RGBHV cable

So here is my question. I have a 24" wide, 19.5" high, 36" long table that fits nicely against the back of the wall. Setting on that table the front of the projector will be 120" away from the opposing wall. The screen will be too big. Why can't I just use the horizontal and vertical shrink to make the screen the size I want. Won't it still be a much better picture than the $300 projector described above? Will this burn the tubes out that much faster? I will probably use this thing 300- 350 hours a year at most. If it lasts 2000 hours I'll get about 6 years.

I've seen the picture of the tube with the little rectangle burned into it so I know it will screw it up for doing a bigger picture later. But this is the only place I will ever use it.

Thanks!

GEBrown · Joined: 08 Mar 2006 Posts: 729 Location: Denver

Yes, that setup will burn the tubes faster. All the brightness comes from the phosphor in the CRT's. As you reduce the size of your rasters, you reduce the amount of phosphor used and you must increase your contrast and brightness settings to get the same illumination on the screen.

But I think you already realize all of this.

As you crank up the contrast, the beam size gets larger, so the overall sharpness of the picture is going to decrease as well.

But heck, try it, if it's watchable for you, then who else cares?!?!?!

Person99 · Joined: 09 Mar 2006 Posts: 4899 Location: Flower Mound, TX

Only thing GEBrown didn't say is that the smaller the raster, the less resolution you can do. But for a free or cheap PJ, I'm with him, who cares!

BTW, if you ever do want to ceiling mount it, I use 2 cheap block and tackles (1 front, 1 rear) like this:
http://www.northerntool.com/webapp/wcs/stores/servlet/product_6970_11839_11839

Dave

whats6x7 · Joined: 04 Oct 2006 Posts: 5924

Yes, I pretty much knew what it would do. What I don't know is how fast.

The CRTs have 5500 hours on them and seem to be in really good shape. If I can get 2000 hours out of them like that I will be very happy. Even 1000 hours would give me 3 years from a free projector. Then if I want to "do it right" I can buy a Marquee from Curt and build a room around it.

It won't be a massive resize and the room is in the basement and totally black. I shouldn't need to crank up the brightness too much.

**AnalogRocks** · Posted: Tue Oct 10, 2006 10:36 pm Post subject:

Do it. I run my 1252 very badly set up right now but it looks ok to me. I have small rasters with the wrong lens spacers and heavy electrical adjustments to fit on a 72inch 4:3 screen with a throw distance of about 7 feet.

One of these days I'll have time to set my living room up home theater style but for now this will do.

I have it on a projection cart that is directly behind my chair.

Here's a picture of the cart:http://www.curtpalme.com/forum/album_page.php?pic_id=293
so your table idea is a good one. To get more light out of mine I tilted the back of the PJ up to make the tubes parallel with the screen. I run my britness at 53 and my contrast at 67 everything looks fine.

the 12xx series is cheap. If it looks good to you do it.

whats6x7 · Joined: 04 Oct 2006 Posts: 5924

Yeah, I think thats what I'll do. Thanks AR. Can I call you AR? If I had any money invested in this thing I might be more careful. As it is, I'm up almost 50 bucks from the sale of the 1020.

Thanks for the tip about tilting the front of the projector to get more light. How long have you been runniung yours like that?

**AnalogRocks** · Posted: Wed Oct 11, 2006 1:03 am Post subject:

whats6x7 · Joined: 04 Oct 2006 Posts: 5924

Nice AR. If thats the image you can get from setting it up badly then I'm sold. That picture is 10 times better than what I could get out of a $300 used throw-away lcd projector. I may have to tweak it a little hot like GEBrown said but but at least it won't be out in the middle of the floor.

I was actually joking around about the block and tackle but its not a bad idea when I get ready to do this thing right. Do you just screw in a couple of temp I-bolts to attach them on the ceiling? No wait, scratch that. I just read Sonynuts experience in ceiling mounting. . . . I'm out. The floor is just fine for me.

**AnalogRocks** · Posted: Wed Oct 11, 2006 10:00 pm Post subject:

Joseph9298 · Joined: 15 Sep 2007 Posts: 2

Is it possible to buy a type of mirror or glass that one could place a foot in front of the projector that would reduce the image size without setting the rasters any different the standard settings?

The proper distance from the screen is 12.17', however, due to vaulted ceilings, I would like to be 18'.
Any Ideas?

Thanks

perisoft · Joined: 29 Aug 2007 Posts: 2920 Location: Ithaca, NY

The lenses determine throw distance - the size of the image at a given distance from the projector. Digitals usually have zoom lenses, which gives you some lattitude; the lenses on CRT PJs don't tend to be zoom lenses, because jesus, we've got enough to deal with as it is without three separate zooms Wink

(Seriously, I don't know why. I'm guessing it's because CRT PJs aren't portable, and the cost of and difficulty of making high quality, huge diameter zooms wasn't worth it for the market.)

That said, you could potentially dig up some long-throw special-purpose CRT PJ lenses. CRT PJs were used in a lot of odd applications and I know there were various lens packages made. But I don't know how readily interchangeable they are optically - and almost certainly unless you got lucky you'd need to do some mechanical work to get them to mount.

If you like messing with it it could be a lot of fun. I wouldn't hesitate. But I'm crazy, so take that with a grain of salt. Smile

Joseph9298 · Joined: 15 Sep 2007 Posts: 2

Hey Thanks
That does not really sound like something I want to get into very much, but I will look into it. I might just have to sell the projector. To put it a 12' I would have to hang it down from the ceiling 5' which is something that would just look hideous, and I would be in the way of the fan light.

draganm · Joined: 08 Mar 2006 Posts: 8990 Location: Colorado

jask · Joined: 17 Mar 2006 Posts: 10187 Location: kamloops BC

6x7 I was just wondering if you are close to any other members that might be willing to help hoist it up? do you have a ceiling mount for this projector? and as for long cable runs you can put a wall unit or shelf on the side wall the same distance from the screen and probably keep the run under 10 feet.
I was able to mount a 1208 on the ceiling alone using the chain and "s" hook method,as a bonus I have the mounting points and chain on hand if I ever need to pull the PJ down.

Fujifrontier · Joined: 20 Oct 2007 Posts: 354 Location: San Antonio, Texas

any info on the 1020 mounting?

Gino · Posted: Mon Dec 10, 2007 12:03 pm Post subject:

how much of a loss in ftL's would one have the further away you mount it from a screen? is there a mathematical relationship?

how about the loss of light output with a smaller raster?

garyfritz · Joined: 08 Apr 2006 Posts: 12088 Location: Fort Collins, CO

ftL = lumens / sq ft of screen. Presumably the screen would stay the same size in this example, so the ftL will be determined by the lumens thrown by the projector. Lumens are directly/linearly related to the area of raster being illuminated. (Assuming you ignore the current-limitation issues with CRTs, anyway, which are not generally an issue with normal video content.) So if you increase your raster area by 10%, you will increase the lumens emitted by 10%. Assuming you move the projector closer to illuminate the same size screen, then the ftL at the screen will also increase by 10%. If you reduce the raster by 10% and move the projector farther away, you'll reduce the ftL by 10%.

9kids · Joined: 25 Jun 2007 Posts: 138 Location: Manassas, VA

Here is a different idea. Put the projector where you what and move the screen closer. You can get a pull down and mount it suspended from the ceiling from some small chain or heavy fishing line. Real easy to do. Then you can set the projector up correctly and get really good picture quality.

**AnalogRocks** · Posted: Mon Dec 10, 2007 6:33 pm Post subject:

Yeah we came up with that one in another thread with losts of forehead slapping afterwards. JustGreg did that is I remember right.

nuttall_chris · Posted: Mon Dec 10, 2007 7:46 pm Post subject: