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Discussion Starter · #1 ·
Is it possible to set up a CRT projector so that you can use the full resolution of the tubes in all three of the vital resolutions, ie 1.33:1, 1.78:1 and 2.35:1?


I was envisioning (dreaming about) a 2.35:1 screen on the wall and then viewing the other formats in their proper aspect ratio but with the same height (ie, not using the full screen width).


Would that make sense - and is it even possible to accomplish with a CRT projector?
 

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I'm no expert, but i think it would be possible if you have clean CRTs.


My CRTs have a 4:3 wear pattern. The max horizontal size i can set the projector to is about 44%, any value beyond that the wear pattern will become visible. So i use that width setting for my 2.35:1 screen. This means that i cannot set the width setting on the projector low enough to make a 16:9 or 4:3 width with the same height as the 2.35:1 :( (And yes, i'm ready to get these CRTs redone so i can use more surface area :) Now i'm squeezing the vertical size all the way down to 4, and that is with the mod that is necessary for the E'home Marquees to do widescreen :eek: ...)


I would think if you have clean CRTs where you can set the width to 95% without any wear showing up, you can use that for the 2.35:1 width and still have a big chance of being able to set the width low enough to reach 16:9 and even 4:3 widths.


If it makes sense is a different matter, and i'm not sure on that. There is such a thing as the beams coming too close together which may make your picture blurry / soft etc. This depends on what projector you'd get though i think. If you get a higher end projector you have a better chance of being able to pull it off than with a lower end projector. Also there's the matter of "ideal" resolution (i'm talking about a HTPC+CRT projector setup here) to match the aspect ratio of the source that you're projecting.


(update)


And after rereading your post :) - you don't need the projector to adapt the horizontal width to get the correct aspect ratio... if you're using a HTPC for example. I'm using a constant height setup. I have my projector set up for my 2.35:1 screen, and always feed it with 1696x720 pixels from my HTPC. On the HTPC i just use whatever piece of the resolution i need for the aspect ratio of the source. In other words, 2.35:1 movies use the entire 1696x720 resolution, but 16:9 movies use only 1280x720, and i have black bars on the sides to fill it up to 1696 pixels width. Same thing with 4:3 material - i only use 960 pizels width for that, and use blackness to fill up the other 1606 pixels. So my projector always gets a picture that's 1696x720 pixels, just a bunch of them are black depending on the AR of the source material.


Just my 2cts, i hope it is of any help :)


Gertjan
 

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Kimmo,

There have been a few on this forum who are doing this now. I'm not usually a name dropper but this is the only way I know to help you. Vern Dias is using (the last I heard) a Runco 991 CRT and constant height. Also Bjoern is using a different concept of constant area with the scope aspect ratio as the largest on down. I've thought about this myself including the possibility of a 144" wide scope aspect ratio down to 106" AT 1.85:1 etc.

Art
 

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Discussion Starter · #4 ·
Thanks for the input! The HTPC solution mentioned by Gertjan seems like a fairly simple way to achieve the effect I'm after.


I'm currently entirely without a projector and looking at what to get and how to set that up.


Hmm, in order to feed a CRT projector 1696x720 I would imagine one needs to fork over a fair bit of cash? Projectors here in my part of the world aren't that cheap to begin with. ;)
 

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Kimmo -


I think some of the dealers of used CRT projectors here on the forum ship internationally, i'm sure they can chime in here or contact you with details.


To do a 1696x720 resolution you'd need a decent projector. A HTPC can be cheap or expensive, depending on which route you want to go. You can build one yourself "from scratch" and do it pretty cheaply that way, or you can buy a completely preconfigured one. I imagine your choice will depend on how computer literate you are.


If you can specify your budget, people here might be able to give you some idea of what your possibilities are.


Gertjan
 

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Discussion Starter · #6 ·
The HTPC is the least of my worries, I work as a system administrator. Plan to build a system myself. One of the bigger problems I have though is figuring out how to silence it, and of course finding a nice looking case that will look good in the equipment rack. The viewing room will also be my living room, so it has to fit in with the sound equipment.


It's the projector that is confusing me. ;)


I'm tempted to go with a digital projector, but that would mean something in the Sony VPL-VW11HT price range (and that is pretty much the absolute maximum I'm going to permit myself to consider - I don't want to live on porridge for the next five years even for a nice projector ;) )


Meaning that my budget is pretty much about $6000 or $7000 on the outside. Not sure what that will buy me; locally (to stay at $6000 or below) it would mean something like a Seleco 420, which I believe won't go over 640x480. The HTPC solution wouldn't work with that machine, I would imagine.
 

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Quote:
Originally posted by Kimmo Jaskari
Not sure what that will buy me; locally (to stay at $6000 or below) it would mean something like a Seleco 420, which I believe won't go over 640x480. The HTPC solution wouldn't work with that machine, I would imagine.
The new Seleco 420 HB will do 800x600. I was thinking of buying one of those myself, but ended up with a used Sony 1270 with nearly mint tubes for the fraction of the price (under $2000). Never regretted.


I'm using Skyworth to feed the projector directly. With NTSC (480p) scanlines are somewhat visible, but with PAL (576p) the image is just beautiful. My screen is 67" (170cm) wide with an aspect ratio of 16:9.
 

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Kimmo -


Glad you got the HTPC side covered at least :)


I don't know if you have a preference for CRT vs digital projector...?


For that budget you should be able to get a used but very good CRT projector i would think. I think that here in the US one should expect to pay $3000-$5000 for a higher end one in a decent shape. In your case you'd have to add international shipping, and i have no idea how much that would run you. You should talk to the used CRT projector dealers on this forum to find out how much international shipping would be. At least it would give you a comparison vs local shopping. Check out this thread http://www.avsforum.com/avs-vb/showt...threadid=91181


Good luck :)


Gertjan
 

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Kimmo,


A 2.35:1 constant height screen is possible with every projector.


On a CRT there a 2 possibilities.


1) The CRT you use has enough latitude in the height/width adjustment to support a 2.35:1 resolution. My Nec XG does, as i just explained in this thread .


2) The CRT doesn't have the latitude. You can only lessen the height of the raster to a 16:9 ratio, if at all. With a HTPC, this doesn't really matter (although method 1 is prefered, see my post in the other thread), because you can build a custom 2.35:1 resolution with large vertical front and back porches.


Either way, with a HTPC you can then simply windowbox every ratio that is narrower (2:1, 1.85:1, 1.66:1, 1.33:1) within that 2.35:1 resolution. People use YXY or the upcomming TT player for that.


While a 2.35:1 screen is great, IMO a constant area screen is even better.


My preference is in this order:

- 4:3 screen (constant width)

- 16:9 screen

- 2.35:1 screen (constant height, except for 2.76:1 content)

- constant area screen


Since i have a large screen with variable 4-way masking (bottom, top, left, right), i can change between these methologies within seconds. This is possible through dozens of presets in YXY.


I don't consider a 4:3 screen to be a valid option in a HT at all. A 16:9 screen is much better. The 2.35:1 screen is another big step up in cinematic experience, but once i implemented my constant area screen, i find everything else lacking in comparison.


You can find more about my setup and the CA ideas on my HT page, see link in signature.


Best regards

Bjoern
 
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