I am new the digital forum and am considering a jvc rs1 but I have a few questions that I am confused about.

How do you change the aspect ratio on a fixed pixel projector and still have the standard 1080/1920 data being shown.

how can you switch from 4:3 or 2.35 or 16:9 without getting the stretch if each pixel is assigned a data bit/ square?

are there scalers that "fill" intelligently the non used areas of the chip so that resolution is not lost?

sorry for the ignorance but I am used to CRT where it molds itself to any aspect and resolution.


steve

Welcome to the dark side. :)

There are a couple of ways this can work.

The first and easiest is to not use pixel elements when the aspect ratio changes. If, for example, you have a native panel resolution of 1920x1080 (16:9 aspect), a 4:3 image would use 1440x1080 pixel elements and leave the other pixels black. This reduces complexity at the expense of resolution loss and larger aspect ratio images being "smaller" than smaller aspect ratio images. IE. 2.35:1 movies take less screen area than 1.85:1 movies.

The other way for this to work requires a scaler that electronically squishes or stretches the image to a 16:9 aspect (always presenting 1920x1080 to the projector's panel(s)) and have multiple lens elements that reverse the effect optically for each electronic squish/stretch. This would be REALLY expensive due to the number of lenses you would need. I don't know anyone who does this.

The most common way people try to strike a compromise is a constant image height (CIH) system where they use a scaler and single lens that makes 2.35:1 use all the native projector resolution. When displaying things of different aspect ratios, they move the scaler and lens in and out of the data path to get the desired result using as many pixels on the panel(s) as possible. There is a forum on this board dedicated to this subject. (http://www.avsforum.com/avs-vb/forumdisplay.php?f=117)

I hope this makes sense to you.

Thanks Huckster,

So if I am watching FOX at 720 over the air on a 16/9 screen it will leave 360 lines black on the top/bottom and fill each pixel square with one line (720)

So now if during a commercial it goes back to 480, does it shrink even more to 1/2 the screen size or does some processor automatically double the pixel count and fill the entire screen.

It seems this would look quite jaggedy if thats a word. Can the scaler fill in the spaces and make it look good?

I am running at least 2 and sometimes 3 different resolutions. I guess it wouldnt look any worse than on the CRT.

I have been to visit a few shops but they dont switch back and forth and I guess it is as you have stated. Pick the one you see the most

steve

Thanks Huckster,

So if I am watching FOX at 720 over the air on a 16/9 screen it will leave 360 lines black on the top/bottom and fill each pixel square with one line (720)

In that case the internal scaler of the RS-1 would fill the entire screen, unless you told it not to. This type of scaling is done very well in modern projectors.


So now if during a commercial it goes back to 480, does it shrink even more to 1/2 the screen size or does some processor automatically double the pixel count and fill the entire screen.


This generally won't happen, because even if the commercial was originally shot in 480, the station itself will scale it up to match the rest of the HD feed (720 in this case). Changing resolutions would require everything downstream in the signal chain to re-sync, causing havoc at every commercial break.


It seems this would look quite jaggedy if thats a word. Can the scaler fill in the spaces and make it look good?


Yes, modern scalers are all very good at simply interpolating between input resolution and display resolutions up to 1080p. The area of differentiation in modern processing is deinterlacing. The best processors are able to deinterlace 1080i film source content and 1080i video source content very well, while the less sophisticated ones loose substantial resolution. The RS-1 has a very good processing chip by Gennum.

See Greg Rogers' excellent reviews of the RS-1 and other projectors for Widescreen Review. It's worth the subscription price.

Also, secrets of home theater and Hi-Fi has an excellent primmer on 1080p scaling and deinterlacing. You can find it here. (http://www.hometheaterhifi.com/volume_14_1/feature-article-1080p-3-2007-part-1.html) Along with much more valuable info.

I hope that helps! Welcome to the wonderful and confusing world of digital displays!