CRT Projectors - Advice needed

[mickeyjaw]

So I was thinking of replacing the bulb in my DLP when I got to think about the idea of buying a CRT projector with the money instead. Does anyone here have any experience with using CRT projectors and shutterglasses? I'm looking particularly in your direction martinlandau as I have heard you mention using them before.

What I particularly want to know is:

1) Does having a fast green phosphor tube really make all that much difference? By that, I mean will the ghosting with a normal green tube be any worse than on my desktop CRT (Iiama Vision Master Pro 514), which has the normal P22 green phosphor?

2) Will the low video bandwidth of these devices hurt the picture significantly more than my crt monitor, or have the DVI-VGA adapter, crap £5 3m long vga lead and oldskool e-dimensional dongle already done such irreparable damage to my video signal that I won't notice the difference anyway?

My monitor claims to have 390Mhz of input bandwidth, but I normally game at 1280x1024 and I have noticed that that the picture looks a lot clearer at 95-100hz than at 120 or 140hz, so I am guessing that my true bandwidth is probably ~180mhz or less ATM.


P.S. Projectors in my price range are:

BarcoGraphics 801s: hsync 15-94khz vsync 37-155hz Video Bandwidth 75Mhz
Seleco SVD 800 HD: hsync 15-72khz vsync 45-140hz Video Bandwidth 75Mhz

or I could save a while and get something more like

NEC XG75: 15-75khz 40-160hz 110Mhz
BarcoGraphics 808s: 15-110khz 37-155hz 120Mhz

The 808s is obviously the ideal solution but would take a lot of saving though.

[martinlandau]

GREAT! I am glaD to see someone else give this a go, avs forum and CURT Palme are a wealth of CRT projector info. MY crt projector has been dissassembled for a time now - originally to clean the CRT tubes - but I have just been too busy to reassmble lately and have been using the 73 inch MITS dlp. I am in a rush right now but have some quick thoughts, CRT tubes fade just like DLP bulbs, so if you buy used, make sure they are not too old. I would say at 6000 hours my sony 1272 is maybe half as bright as before, so I need a totally dark room for the best experienced. Do not even consider stereo3d unless you get the fast response green phosphor, you have to minimize ghosting every way you can, maybe andrew woods can chime in. Video signal - LOL! I used to think that silver serpent high grade cabling was so silly. Then I tried to drive a high bandwidth signal from my ATI radeon to the 1272 over a 9 foot cable, OOPS! A 3 foot silver serpent cable later and everything was looking nice. Also the 1272 CLAIMS a 1600x1200 resolution, that is not exactly correct, you will get 600P or maybe even 650P at best, depending on how good your calibration is. Still some like the softening effect of driving the higher resolutions, I do not, so in my case 800x600 was the maximum res, definitely if I was going with another CRT solution, I would get one of the higher end sony, nec's or barcos. The barco 808's are some of curt palme's favorites - do a search if you don't know of him or his website. But honestly, I am buying one of the new short throw DLP projectors as soon as I can get one, I loved my CRT, but I am tired of fighting with drivers, OS's, DRM, etc etc and have surrended my soul to the state - but I support anyone that wants to keep the analog world alive and keep big brother out of thier life and his digital rights control - UGG!

[cybereality]

I don't really know much about CRT projectors, but I thought I'd mention the Viewsonic PJD6220-3D is selling for under $650 these days.

[mickeyjaw]

Also the 1272 CLAIMS a 1600x1200 resolution, that is not exactly correct, you will get 600P or maybe even 650P at best, depending on how good your calibration is. Still some like the softening effect of driving the higher resolutions, I do not, so in my case 800x600 was the maximum res

Yeah that's why I made the point about video bandwidth. According to my calcs, 1600x1200 @ 60hz requires 176.7Mhz of video bandwidth, which is way out of band for your 1272 and that's only barely enough of a refresh for 2d. Curt Palme's site says your 1272 only has 85Mhz of bandwidth, 113hz is the best refresh you can get at 800x600 and 75hz at 1024x768.

I think my best bet is to try to get a BG808s if I can as you get 120Megs of bandwidth with them and i am led to believe that the tubes are higher res and brighter too. I am sure I have read about these being run at 1024x768@96hz for 3d somewhere, and that would seem to make sense as that requires 119.4Megs bw, right on the limit. Should be possible to do 1280x1024@60hz for 2d stuff and 1400x1050@110hz interlace sits nicely just inside the bandwidth limit (115Megs) too, if i can persuade my pc to output it.

Even the BarcoReality909 one of the last and best crts made by barco with it's supposed 3200x2500 resolution can only just handle 1600x1200@60hz within its bandwidth constraints (176Mhz out of 180Mhz Max).

I don't really know much about CRT projectors, but I thought I'd mention the Viewsonic PJD6220-3D is selling for under $650 these days.

Yes this and others like it (6211,6222) tempted me until i realised that they use checkerboarding. I'd rather just relamp my NOBO X20P (a rebadged EP7150) and continue to put up with 85hz. Now if they were true 1024x768@120hz i would be sorely tempted. I may be tempted by the HD65 3D if/when it ever comes out but I would have to see first hand how much the checkerboard bothers me before buying I guess.

The 3D plasmas also use checkerboard and ghost to boot, so they don't sound too appealing, and the only other option for big screen gaming is the DLP 3D RPTVs, but no-one sells them here in England. If I could buy one here for the US price I would have one already, but by the time I pay to have it shipped here and pay import tax on top of the combined item+shipping charge then VAT on top of that the price has more than doubled, which is waaay outside my budget.

This leads me back to the idea of a CRT - don't gain hugely in 3D res over my DLP, but gain more refresh and get the potential for higher res and a better contrast ratio for 2d stuff.

[martinlandau]

Contrast Ratio, the BANE for digital for so long, but that is quickly falling away. For years I was able to laugh at my digital brothers with their 1000:1 next to my roughly 20,000:1 - ahh -blade runner, tron, the matrix, star trek the wrath of khan, all those wonderful DARK movies they just couldn't match Some of the new LED and laser stuff has so much CR it makes my sony pale in comparison!

the only other option for big screen gaming is the DLP 3D RPTVs, but no-one sells them here in England. If I could buy one here for the US price I would have one already,

Wow, see there are some good reasons to live in the USA.

but by the time I pay to have it shipped here and pay import tax on top of the combined item+shipping charge then VAT on top of that the price has more than doubled, which is waaay outside my budget.

Good lord, didn't you brits ever study the benefits of free trade and how over taxation cost you the colonies! Budget? I am sure there are things you can do to fix that, give up your wife/girlfriend. sell your cars and ride bicycles, give up meat and only eat noodles. there are LOTS of sacrifices you can make, I know you can do it! This hobby is worth it! A big problem I have with the CRT stuff is that I am going to be projecting onto a dome to get a wide FOV, and ultimately plan to do a z-screen - polarization rotator to be able to use passive glasses, and they don't make them big enough to cover the 3 lenses of the CRT projectors. Have you not considered dual projectors like likay and friends have? I would have went that route, but same problem, projecting onto a dome that will just add complication. I am ecstatic you are seeking a big screen solution though, there is no way I could go back to serious gaming on a 22 inch monitor after a 10 foot screen, that is such a chump off.

[AWoods]

Given the ultra-sharp images we are now used to seeing with DLP projectors, I think you'll be disappointed by the lack of image sharpness provided by a CRT projector. It used to be the only way, but expectations change with advances in technology.
CRT projectors also ghost more than DLPs as others have mentioned.

[mickeyjaw]

Given the ultra-sharp images we are now used to seeing with DLP projectors, I think you'll be disappointed by the lack of image sharpness provided by a CRT projector.

That's fine it means that I don't have to turn AA on which means more FPS. The projector will be for gaming/TV not reading text on, and for the same price as one new DLP bulb but with about 10x the lifespan I think I can deal with that.

CRT projectors also ghost more than DLPs as others have mentioned.

Yes, but do they ghost more / less than CRT monitors? I find the level of ghosting on my Iiama CRT quite tolerable, surely with a fast phosphor tube projector it can't be any worse can it? (But please let me know if this is not the case)

The only 2 things I am really woried about are the level of light output and where I am going to put the damn thing (will need to rearrange living room therefore missus will complain).

[budda]

Hi,

There is always the possibility of going fully red with a CRT projector in 3D.

The red phosphor in a CRT works best for shutterglass applications, as previously described in the "Red Eye Shutterglasses Method".

Some unconventional viewing opportunities exist here.

It seems the red tube has the longest life in a CRT projector - possibly 20,000 hours. So if you have an old CRT projector with worn out Blue and Green tubes you can still put it to some use for 3D, by only using the red tube for the display.

Other interesting 3D options could be developed by replacing the Blue and/or Green tube with another Red tube.

For example - Red/Blue anaglyph could become Red/Red polarized from one projector.

Thanks.

[martinlandau]

Hi,

There is always the possibility of going fully red with a CRT projector in 3D.

Other interesting 3D options could be developed by replacing the Blue and/or Green tube with another Red tube.

For example - Red/Blue anaglyph could become Red/Red polarized from one projector.

Thanks.

Great stuff Budda, I remember curt talking about this years ago, and conceptually all I could think was Nintendo Virtual Boy Tennis in all it's red glory on a stereo3d projected solution. Has anyone actually seen one of these mutli red tube projector solutions? I would be curious to thier personal impressions. Where is the link to this other thread you are talking about Budda? Thanks dude.

[budda]

Hi,

The "Red Eye Shutterglasses" post is located at http://www.mtbs3d.com/phpBB/viewtopic.p ... 879#p10879" onclick="window.open(this.href);return false;


And more significantly in Wikipedia - http://en.wikipedia.org/wiki/Stereoscopy" onclick="window.open(this.href);return false;


Thanks.