[David A. Frattaroli]

If a projector is a native 800x600 device, how does that compare to a typical rear-projector television? Is this even a valid question? In other words, is a rear projectors native resolution closer 800x600 or 1024x768?


Thanks.

 

[Jason Turk]

Basically, a digital projector, whether it be LCD, DLP, or D-ila, has a fixed panel that is a certain resolution. Generally, when you input a source to that type of projector, if the signal does not match the native resolution, then the projector scales the signal to match the resolution of that projector. In contrast, a RPTV is a CRT based, analog system. They have the capability of scanning to certain frequencies, but the picture is more dependent on what you feed it. So if you fed a RPTV a 480i DVD signal, that is what you would get out. Most of the newer CRT based RPTV can scan higher than the older units and have built in doublers to improve picture quality. There are also digital RPTVs coming out, and they work by the same principal as the front projection units do.


Thanks!


------------------

Jason Turk

AV Science, Inc.
http://www.avscience.com

716-454-1460

[email protected]

 

[David A. Frattaroli]

Thanks, Jason. So it sounds like I'm comparing apples and oranges then, right? I'm trying to determine if an 800x600 projector will be good enough or if I need higher resolution.

 

[Jason Turk]

A good 800x600 projector can yield a better picture than a RPTV if the screen size isn't too large. We have a Seleco HT200 here in one of our showrooms and that projector looks incredible on a 8' wide screen. I'd say it would blow away just about any RPTV out there.


Thanks!


------------------

Jason Turk

AV Science, Inc.
http://www.avscience.com

716-454-1460

[email protected]

 

[camoura]

And how a 800x600 projector compare to a 1024x768 ? Is it worth the higher price ?


Thanks,


camoura

 

[Jason Turk]

A lot of that depends on the projector. I've seen 1024x768 presentation projectors that don't even compare to the Seleco HT200, which is a 800x600 unit. The design of the projector and its intended use (ie. home theater or presentation) makes a big difference on the result you get.


Thanks!


------------------

Jason Turk

AV Science, Inc.
http://www.avscience.com

716-454-1460

[email protected]

 

[camoura]

Jason,


Ok, but in theory 1024 is better than 800 because there are more pixels per sq inches, right ? So, is it worthy ? I mean am I going to notice any difference playing dvd's, watching TV, surfing the net ?


Thanks,


camoura

 

[David A. Frattaroli]

camoura, I think if you compare to otherwise identical units like the LP350 and LP340 that projected onto the same screen, the 350 would yeild a superior image due to the higher resolution. However, if you project an image of greater than 8' diagonal, the 350 would continue to display a sharp picture whereas the 340 would start to fail in comparison because 800x600 is not enough pixels for such a large image.


So is it worth it? That, I guess, depends on the size of the image you intend to project and also on your personal preference. So, you might not know till you see them.

 

[Morbius]

camoura,


You also have to consider the native resolution of the

material that you are going to project.


The 1024X768 resolution is greater than the native

resolution on a DVD, for example - which is what

Jason of AV Science pointed out.


Greg

 

[PeterF]

I have been trying to compare SVGA vs XGA. I am thinking about the InFocus LP260 (SVGA) vs the NEC LT150 (XGA). The largest my screen will be for the foreseeable future is 5 to 6 feet diagonal. Will there be much difference between SVGA and XGA at this distance? I only watch movies on DVD and I don't care what sports and news look like off of cable. All I care about is that DVD's look good (at an affordable price - $2000 - $3500).


Thanks for any and all input.

 

[davidahn]

David, regarding your original question, a typical rear-projection TV uses 7" CRT tubes, which in general have about 1000 to 1200 TV lines of resolution, which roughly corresponds to XGA. However, at such a resolution it is slightly fuzzy, whereas XGA at native resolution is razor-sharp (and with video, maybe even TOO sharp). The advantage of CRT technology is that at ANY resolution it is "native", not requiring scaling at all, giving you NO scaling artifact. Any digital technology will ALWAYS have to be scaled unless it's at PRECISELY the resolution of its panels (and currently, NOTHING is in the exact resolution of ANY of the panels: 480i/p (NTSC/DVD), 720p, 1080i, do NOT correspond to VGA, SVGA, XGA, SXGA, UXGA, or QXGA, and require scaling. The internal scalers vary widely in quality, though the later units are fairly decent as a general rule.


I think it would be worth the extra money to get at least XGA (1024x768) resolution in light of the growing availability of HDTV materials you can display on them. For DVD, SVGA may be fine, but for 720p or 1080i, you could DEFINITELY use the higher resolution (though it would be scaled down to XGA). Basically, I recommend the highest resolution you can get your hands on (that also support accurate colors, good contrast, and decent black level). The XGA projectors also have less visible pixel structure because at a given screen size you have a finer pixel grid.


David

 

[David A. Frattaroli]

Thanks davidahn. Excellent post.