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Sony Plasma Screen Resolution for Widescreen PC Output

Overview:
I am building a Media Center to be connected to a Sony KE32TS2 Plasma screen however after a bit of experimentation I found the plasma was displaying 1024x768 but stretching it to fit the 16:9 screen and hence distorting the picture. Not an ideal solution. I set out to find a way of display the proper native resolution of the screen from a PC. This took a considerable amount of time to research, my findings are documented here.

Setup:
I currently have the plasma screen connected to my PC using a 15pin VGA to 5x Phono cable which connect to the RGBHV sockets on the plasma screen.

Pixel Perfect :
After a quick search on Google I came across a company called Imagine Graphics that sells a graphics card with specially written drivers for displaying at several resolutions for plasma screens. It turns out this is what is used in many airport worldwide to display departure and arrivals information on their displays.

I found a lot of good information on the site, espeically about ALiS displays of which the KE32TS2 is one. This explains why the resolution of the display is 1024x852 which didn't make sense to me at first since this would not make up a widescreen picture. The key is that the pixels are rectangles and not squares and in actual fact the picture is interlaced. After reading this it became clear that the display is primarily meant for video, not displaying a windows desktop and displaying clear text may be an issue.

I was impressed by the card and its capabilities however I did not have the budget to spend the £250 that it costs. Therefore I continued my search to find an alternative solution.

ATI HDTV Adaptor:
I noticed this adaptor when looking at ATI's website. It enables some ATI graphics cards to output component video at HDTV resolutions. Outputting at 720p (1280x720) and then letting the plasma scale the image internally may produce a good result. Unfortunately for me the adaptor is only available in the US.

PowerStrip:
After more searching I came across a program called PowerStrip which enabled tweaking of many function of the graphics card. It allows selection of custom resolutions and even has a list of many widescreen HDTV resolutions. This is exactly what I was after. After installing I tried many different resolutions to find the best result for the KE32TS2.

Test Results:

Test Performed with ATI RADEON 9800 Pro Graphics Card:

Best result was recreating 720p with settings below:

RAMDAC:
Pixel Clock 74.160 MHz

Synchronization:
Horizontal: Positive
Vertical: Posititve

Non-interlaced, no composite sync, non sync on green

Horizontal:
Scan rate: 45.000 KHz
Active: 1280 pixels 17.260 us
Front porch: 72 pixels 0.971 us
Sync Width: 40 pixels 0.539 us
Back porch: 256 pixels 3.452 us
Total: 1648 pixels 22.222 us

Vertical:
Refresh Rate: 60.000 Hz
Active: 720 lines 16.000 ms
Front porch: 5 lines 0.111 ms
Sync width: 5 lines 0.111 ms
Back porch: 20 lines 0.444 ms
Total: 750 lines 16.667 ms

Notes: Image is overscanned, start bar etc... is half on-half off screen. This can be adjusted by screen adjustment menu on the tv. This allows all the windows desktop to be seen.

Important: Positive Horizontal and Vertical Synch

Other resultions:

Diffcult to get clear pixel for pixel reproduction from windows desktop to screen. ALiS display is not for this purpose, it is for video. This is why it is best to use 720p and let the display scale the image to obtain best performace and resoltion. Disadvange is text obviously not as clear and well defined due to the scaling process. However enabling cleartype fonts makes a big improvement.

Screen is constantly shifting to minimize burn in effect, therefore I guess you would have to oversive image slightly to get perfect pixel for pixel reproduction. Can be turned off but not advisable.

848 x 480 appears as 1080i display does not fill screen however could be adjusted on tv control
856 x 480 appears as 1080i display does not fill screen however could be adjusted on tv control

852 x 512 appears as 640*480/60 displayed as 4:3
852x1024 (interlaced) appears as "others" and displayed very brown in colour, basically not viewable!

1920 x 1080 (interlaced) displayed well, requires slight screen adjustment to fill screen.

Update 04/04/2005:
The new ATI graphics drivers provide support for HDTV resolutions. I have set the PC to output at 720p. I am using the Nebula digital tv card. Use of the bob deinterlacing method seems best as the line average method produces jerky motion when the camera is panned. Menus flicker slightly but this is probably due to the ALiS display scaling. Apparently according to this post, the ALiS display will down-convert 720p to 512 rows and each frame will displayed on alternate rows - probably the cause of the flickering. ALiS is obviously best for 1080i due to its interlaced nature. :(