[David Ellis]

Stupid question - are screens measured diagonally as with rear projectors and so on?

Yep.

I continue to use a nicely painted wall with very good results.  2 coats of Behr primer with 2 coats of Behr Ultra Premium White are very pleasing.  I sanded lightly between coats to remove the tall speckles from the roller.

Probably the only thing I might change is the size of my screen.  It's @ 106", and I think slightly smaller would be better.  It provided slightly better color saturation.

My Optoma H31 has dropped in price to @$600 via visual apex.  It might only be a 480p projector, but the picture quality remains excellent IMO.

I think Optoma recently released a 720p dlp projector for $1k. This would be my decision if purchased today.

Dave

[ctviggen]

Actually, who cares about 1080p?  I think 1080i is still a worth goal, unless I am really missing something - 1080i is going to look substantially better than 720p at these screen sizes, no?  But until one of the new formats wins (and maybe not then) 1080p is rather pointless.

My current 50" LCoS Sony does 1080i and looks amazing with a relatively cheap upscaling DVDP.

If I could get a decent 1080i PJ and 110" screen for under $2K I'd be there.

Paul, for some reason in front projectors, they don't make 1080i (at least none that I can think of).  It's either 720p or 1080p.  The cost difference between these has come down quite a bit, but it's still 3k plus for 1080p.  There's been a recent thrust to provide more light output, aka lumens, for the 720p projectors.  So the new Epson and Panasonic 720p projectors can get very bright.  The same thrust hasn't happened for 1080p, but should one of these days.  Thus, I'm thinking of going with a reasonably priced 720p projector for a while, to get my feet wet in this area without killing the bank. 

[PaulFolbrecht]

Paul, for some reason in front projectors, they don't make 1080i (at least none that I can think of).  It's either 720p or 1080p.  The cost difference between these has come down quite a bit, but it's still 3k plus for 1080p.  There's been a recent thrust to provide more light output, aka lumens, for the 720p projectors.  So the new Epson and Panasonic 720p projectors can get very bright.  The same thrust hasn't happened for 1080p, but should one of these days.  Thus, I'm thinking of going with a reasonably priced 720p projector for a while, to get my feet wet in this area without killing the bank. 

I'm thinking the same thing right now - Panny ax100u can be had on eBay for around $1500.

[Rob Babcock]

The Sanyo Z5 is another good option, down to about $1500 new.  There isn't much of anything for less than 2x or 3x it's price that can match it's sharpness.  The new Panny is a good deal, too.  I've lived with a PJ for years and wouldn't dream of going back to a big old hulking box tv.

When I get my bonus in Feb I'll be upgrading PJs, too.  I think I'm going with the Mitsubishi '1000U.  My thinking is I'll use it for a year or two, and by then 1080P ought to be about where the top 720P's are now, price wise.  $4000 is more than I want to drop on a PJ, but once good 1080 models are down around $2,500 or so I'll probably jump.

[wshuff]

Actually, who cares about 1080p?  I think 1080i is still a worth goal, unless I am really missing something . . .

Paul, for some reason in front projectors, they don't make 1080i (at least none that I can think of).  It's either 720p or 1080p.

You're confusing display resolution with input resolution.

All of these digital projectors, whether LCD, DLP, or LCoS (i.e., JVC's HD-ILA and Sony's SXRD) are fixed pixel displays, meaning that the image is produced by a chip with a specific number of pixels representing the display's native resolution.  In the case of a 720p projector, that means 1280X720 pixels.  For a 1080p projector, that's 1920X1080.  Unlike CRTs, all of these microdisplays are inherently progressive.  So, no matter what input resolution is received, be it 480i, 480p, 720p, 1080i (or, if it accepts it, 1080p) a 720p projector will display it at it's native rate, i.e., 720p, while a 1080p display will display everything as 1080p. So, for instance, Paul's Sony (which I presume is a 1080p display) does take 1080i as an input resolution, but the display is processing that input to display it as 1080p. 

[ctviggen]

I know exactly what input and output resolution is.  I think that when one transitions from the world of rear projection/regular TVs to front projection, it's a bit different.  For instance, my RPTV shows 1080i (as input and output) but does not show 720p (either input or output).  However, front projection only shows (as output) either 720p or 1080p.  The input doesn't really matter, as everything is scaled to 720p/1080p. 

[wshuff]

I know exactly what input and output resolution is.  I think that when one transitions from the world of rear projection/regular TVs to front projection, it's a bit different.  For instance, my RPTV shows 1080i (as input and output) but does not show 720p (either input or output).  However, front projection only shows (as output) either 720p or 1080p.  The input doesn't really matter, as everything is scaled to 720p/1080p.

I don't think its really a matter of front projection versus rear projection.  It is the type of display, CRT versus digital.  If your RPTV can display 1080i but not 720p, I'm guessing it is a CRT.  The digital displays like LCD, DLP, of LCoS, whether rear projection or front projection, are all fixed pixel displays that are only capable of displaying a progressive picture.  That's not true for a CRT, where the picture is created by a scanning electron beam.  I'm having trouble remembering the terminology, but with a CRT, what resolutions were available depended, I think, on the scan rate (?).   

It's been a while since I read this stuff in the projector reviews, but roughly, standard definition video was 525 lines @ 30 frames per second, interlaced.  That means that with a CRT, half the lines were displayed every 60th of a second, or 15750 lines per second.  Video grade CRT projectors therefore had a scan rate of 15.75khz (I think).  Now, for a CRT to display a standard definition, progressive signal, it had to be able to scan at twice the rate, or 31.5khz.  I don't recall if that was called data grade or what.  To get 1080i, the CRT would need a little higher scan rate (540 lines @ 60 = 32.4khz).  Now look at 720p.  That requires a jump up to 43.2khz.  I think that some CRT displays (including, possibly, my Toshiba) could accept either 1080i or 540p because the scan rate was essentially the same.  But mine wouldn't do 720p.  There were a few CRT RPTVs, though, that could do 720p, and there were CRT front projectors that had scan rates that could accommodate about anything you wanted to throw at them.  Those were the ones that cost big bucks, the 8" and 9" tubes, and were often paired with big buck line triplers and quadruplers.

Anyway, these days most projectors are digital, so while they'll accept 1080i as an input, as you say, they are going to scale everything to their native rate for output, so output is always going to be progressive.  That will be true whether you are talking about a digital front projector or a digital rear projector, and that's the reason that they don't make 1080i digital projectors.  But it isn't true for a CRT-based display.