CurtPalme.com Home Theater Forum

J.man1503 · Joined: 28 Oct 2007 Posts: 19

Hello,
I am a complete newbie to CRT projectors. I have only seen 2 in operation (that were not home theater) and that is it. I have read the introductory material 'CRT Primer" that Curt Palme has provided. Also I read the forum post that was for begginers. Now I do not know what to do. I am interested in buying a CRT within the next six months and definitely want it to be 1080p capable. But I do not want to go over $3k. I know that is somewhat limited, but I can find a very good performing 1080p digital for that price. I have a completely dark room with black walls, ceiling, and dark carpet. I desire a 2.35 display as that is what I most normally watch. I guess my questions are as follows:

1. What <$3 CRT's do 1080p adequately? (I read in the for sale area about a Runco 991 Ultra that is "1080p" ready. Does that mean that it will fully resolve 1080p or just accept the signal?)

2. What special precautions do I need to make in order to have 2.35:1 aspect screen?

3. Where could I find a good calculator for my screen distance and screen size?

4. Is this type of set-up even possilbe with my budget?

Thanks, and I am sorry if these questions have been addressed already, I looked at the forum but it was over 100pp long! So if someone could either answer my question or just direct me to the correct material it would be much appreciated!

j.man1503

**kal** · Posted: Thu Apr 10, 2008 3:39 am Post subject:

Don't look for 1080p. 1080i is just as good. Both are 1920x1080 rez but 1080i only takes half the bandwidth so almost all CRT projectors will do this. You'll be able toget a reasonable one for $500-1000. You'll be able to get an extremely good one for $3K.

Kal

J.man1503 · Joined: 28 Oct 2007 Posts: 19

Okay I understand that 1080i and 1080p have the same amount of resolution. But will a $500-700 projector (or any 1080i projector for that matter) fully resolve all 1080 lines? Or will it scale it to 540p like some (if not most) digital displays.

ecrabb · Posted: Thu Apr 10, 2008 4:01 am Post subject:

Welcome to the forum!

No, the CRT won't do anything to the image like a digital. If you feed it 1080i, it will display all 1080 horizontal lines. The better the projector and bigger the screen, the more visible those lines will be. At the high end, the lines are so sharp and obvious, you have to deinterlace to 1080p to eliminate the scan lines.

1. We can discuss what your definition of "adequately" is, but there are several CRT projectors that if set up with great care and attention to detail, will display an excellent 1080p image.

2. There are two disadvantages to using CRT with a 2.35 screen. First, you sacrifice resolution on whatever narrower aspect ratio material you do watch. Second - and this is a biggie - you really need a scaler to do it right if you don't want to go all HTPC as your only source.

3. It depends on the projector (tube size) and lens. Some projectors have throw calculators, some do not. Even if one is available, it's quite conservative, and your actually installed throw would be much shorter - 10%, possibly 15% shorter.

4. The budget is a little tight for 1080p on a scope screen, but then I think it will be impossibly tight with a digital projector, too. I don't keep up on digital stuff - What 1080p digital projector and anamorph lens comes in under $3k?

Also, here's a thread from one of our regulars and long-time CRT user, where he's kicking around the move to a CIH scope screen
http://curtpalme.com/forum/viewtopic.php?t=9374

SC

J.man1503 · Joined: 28 Oct 2007 Posts: 19

Well when I speak of 2.35 (I probably should have clarified this), this is what I currently do with my 720p projector: I made a 2.35 screen and I just project (with out anamorphic lense) the image onto the screen. The black bars are still present, but they are off the screen, so they disappear into the black. This is commonly referred to as zooming 2.35. I suppose that I wouldn't require 1080p 2.35 as I would only need to resolve approx. 817 lines BUT in a 2.35 aspect ratio, so only using a limit area of the phosphurus. Approx 817 lines is only how much information is in the original source (in a 2.35:1 1080p source like Blu-ray) anyway, so that is all I would want. Not a true 2.35:1 setup I know, but it works very well. A projector that is awesome (in the digital world of course) that is under 3k is Epson 1080ub. So the resolution that I need the CRT to project is a 817x1920 image in a 2.35 ratio. Does this make sense?

thanks for your quick response.

MikeEby · Joined: 24 Jun 2007 Posts: 5237 Location: Osceola, Indiana

J.man1503 · Joined: 28 Oct 2007 Posts: 19

But will 817x1920 be fully resovled in a 2.35 aspect ratio? I realize that this would be a stupid question for digital projector, where the pixels are always the same size. But with a CRT, the pixels can change sizes correct? So I could very well get a 817x1920 on a 4:3 image, but what about 2.35 image? 2.35 is not using a very big part of the CRT correct? Perhaps I am not understand how a CRT projects a 2.35:1 image. Does it not just use a strip of phophurous in the center, no stretching or squeezing (or zooming in my case) like in the digital?

MikeEby · Joined: 24 Jun 2007 Posts: 5237 Location: Osceola, Indiana

Yes it does use a narrow strip but because a CRT is an analog device its limited by bandwidth of the electronics not the phophurous grain. By lowering the vertical resolution you are lowering the bandwidth requirements.

Mike

J.man1503 · Joined: 28 Oct 2007 Posts: 19

How would a 817x1920 be limiting the CRT bandwidth? Also I think all I would need is a projector to fully resolve 1080 lines in 16:9 format. Because when I watch a 2.35 movie, I would simply pull down my 2.35 screen. When I would watch a 16:9 movie I would pull that down. So any projector that says it is 1080i compatable, means that it is capable of resolving 1080 lines on the ENTIRE phosphurous correct? So that means only approx. an image of 1440 by 809 would be projected for a 16:9 image correct? Which WOULD be 16:9 but not fully resolve 1080 right? I apologize if I am making this more difficult than it needs to be.

ecrabb · Posted: Thu Apr 10, 2008 4:59 am Post subject:

You're asking all the right questions - you're obviously no newbie.

There are several constraining factors that determine what a given projector will or will not resolve. I'm generalizing big-time here, but the tube's spot size, the lenses, and the electronics all must be up to the task. You are correct that in one way, displaying 1920x817 on a scope screen will be no different than 1920x1080. Your idea that the spot size and lenses must still be up to the task and that it really isn't any different from the full 1080 signal is correct. Assuming that the tubes and lenses are up to the task, then it's only whether the electronics have the available bandwidth with which to faithfully reproduce the signal.

That's the part Mike was keying on. If you use a scaler or HTPC to send the projector only the 1920x817 portion of the full 1080p signal (instead of including black bars), that signal's bandwidth will require only approximately 75% of the bandwidth the full 1080p will. There are projectors where the full 1080p signal would exceed the projector's available bandwidth and would result in a softened image. On the other hand, sending only 817 lines might be much better resolved by the same projector because of the lower bandwidth.

Of course, if you're going to get into processors, then we can talk about doing things like 1920x817/96i. Same bandwidth as 48p, and an even multiple of 24fps film source for both silky-smooth motion and much lower bandwidth (and therefore sharper) than 60p or 72p.

SC

J.man1503 · Joined: 28 Oct 2007 Posts: 19

So as I am reading about these projectors that can (according to Curt Palme's comparison list) can fully resolve 1080i, that is not a question of how big the phosphurous is, but how willing the electronics are to pass the high badwidth? I do not think that I am quite following. If a projector is capable of display 1080i (assuming that is in 16:9) then I should have no problem? That would mean there are many projects in the intermediate level that would do the job, 817x1920 or even 1080x1920i correct? But if it were that easy then I some how think that there would be no need for the higher end projectors with 9" tubes ect. What am I missing?

**AnalogRocks** · Posted: Thu Apr 10, 2008 5:20 am Post subject:

Keep in mind a CRT projector paint's the phosphor with lines ( sweeps from the electron gun ). It's not a fixed pixel device like your digital. So if you send it 1920x817 and leave your image full tube top to bottom it would look vertically stretched and the scan lines would have obvious spaces between them (see Fig.1 below ).

Now when you have this signal going into your CRT projector you goto the projector's controls and squash the vertical size down until it's back to 2.35:1(Fig.2).
This brings your scan lines closer together. The empty black spaces get filled in as you draw the lines closer together and the picture looks better and brighter ( you're painting the phosphor closer together instead of having the voids between the lines )

J.man1503 · Joined: 28 Oct 2007 Posts: 19

I understand now with the sqeezing from the controls of the image. Now what kind of projector would I need to display a image like the one above? Namely a 817x1920 picture? Would anything that resolves 1080i be adequate? Or when a CRT projector states that it can resolve 1080i it means 1440 by 1080i? Translating that I would need a CRT that would resolve 1920 by 1080i (meaning a 9" CRT)? I know that this is probably too general of a question. If someone could go over to the Products for sale where the CRTs are for sale and tell me which ones could do this, maybe I would understand more. Thanks for all the responses to the newbie!

**AnalogRocks** · Posted: Thu Apr 10, 2008 5:41 am Post subject:

Most all of the projector's for sale here can do 1080i, some can't but those are few and far between now.

If you want to run 1080i, scaled to 1920 x 817, and want a great image go for one of the EM ( electro magnetic focus set's ) you'll be at that price point at $3000 easy. Say a Marquee 8500LC (8") , a Sony G70 (8"), Barco 808 (8"), NEC 9PG Xtra (8"), NEC XG 110 (8"), so yeah all 8" EM focus set's. The Marquee and the Sony are a little easier to setup for a first time CRT'er, but the NEC's really shine once you nail the setup.

What are you running for a screen? Many of use use Wilsonart counter top laminate ( seriously ) looks great. Inexpensive too.

J.man1503 · Joined: 28 Oct 2007 Posts: 19

My screen is a Phiefer 4500 acoutically tranparent screen with 15* tilt. It is a 2.35:1 aspect ratio screen. 88" wide. Will one of those projects be sharp and not blurred (because the pixels would be over lapping) when I fed it a 1920x1080i signal and speezed it to 16:9 ratio? Thanks for the response and all your help!

J.man1503 · Joined: 28 Oct 2007 Posts: 19

How would a Ampro 4200 compare to the NEC that was mentioned in the above recommendations? I notice that the Ampro is in the same price range, but has higher resolution, bandwitdth, and contrast than the NEC. Does the NEC have some hidden feature that I do not know of, or does the specs of the higher res, ect. just the manufacturer exaggereating specifications?

naughty_gal_123 · Joined: 10 Apr 2008 Posts: 1

ok so in my posesion i have a SONY MULTISCAN PROJECTOR VPH-G70, it is my fathers and he brought it a few years ago cause it was big and he thought it looked flash. well now im trying to sell it but ive no idea what its worth ive had an offer of $900 is that good? should iaccept it? ive checked the tubes according to a US website and it seems they are in good condition.

mike calcott · Joined: 18 May 2006 Posts: 307 Location: Australia

This projector is now sold seller has accepted offer

**kal** · Posted: Thu Apr 10, 2008 12:55 pm Post subject: Re: Newbie question...

**kal** · Posted: Thu Apr 10, 2008 1:36 pm Post subject:

j.man1503 :

You're obviously not a newbie as others have pointed out so I'd caution you to not look at some of the very entry level 1080i capable projectors - go up a few notches to at least an 8" EM. LC would be nice too. The later the model the better as it'll be more stable. While some of the projectors from the early to mid 90's still run perfectly well, the hours and age do affect the electronics (mostly the electrolytics caps) which cause image drift. You can replace caps yourself if you have the time and the patience and about $100 but it's not something everyone can do.

Where are you located? That would help.

See our "Best/Worst" list here for reference too: http://www.curtpalme.com/Projector_Rankings.shtm

Maybe I'm biased, but I would stick in the "High Performance" models. If you can find an 8" EM LC machine like the one I use they're extremely good. The only difference between the high end 8" and 9" models is resolving power. The 9" machines absolutely must be run at 1080p (assuming full height phosphor usage) as the scanlines would otherwise be too objectionable.

Kal