Samsung 42 plasma HDMI DVI PRoblems

Question

I have a Samsung 42 inch Plasma which I have been using as the second monitor for some time now. I run nvidia Graphics card with two DVI ports. The plasma has a VGA port and HDMI.

I have up until now been using the VGA port with a DVI/VGA converter to connect with the graphics card using the analog pins in the DVI convertor; this works fine only the horizontal pixels are stretched to 16:9. With this analog setup I was unable to use the option within the Nvidia control panel to ‘scale the flat panel’. The stretched image was starting to annoy me so I decided to try HDMI>DVI. The option to scale the stretched image was available and I could get the desired resolution but the picture quality was very very poor. The only time that the quality looked ok on the plasma was when I had it set to unscaled and the lowest possible resolution (which looks plain stupid to be quite frank)

I have tried a program (which I have since forgotten the name) to resize the pixels when using analog but I was unable to get anywhere with this.I saw this post previously DVI to HDMI cable problem and do not believe it to be a cable problem as I have tried two different cables with the same result. I have since reverted to VGA.

Could this just be the resizing of the pixels causing problems? Or just the compatability of the TV..? Does anyone have suggestions? I either want to resize the analog or get the HDMI/DVI working at a reasonable quality.

Answer 1

This is usually down to a variety of problems.

Modern TVs are a lot better at displaying computers - but the older ones are simply, in no way, as good as computer monitors.

The main one is probably down to native resolution - You want your machine to output at the same resolution as the tv - failing that, you want it to be smaller AND turn off any setting that yor tv has such as "expand image", "fill image" or similar. This option usually expands the picture incorrectly. For a general movie or tv, this is fine - for doing something precise like you do with a computer monitor - it is awful.

To give a bit more information, imagine a 4x4 grid, If you said "Expand this" to a 8x8 grid, you may get some luck as it will make each block in to a 2x2 of the same image. If however you try to expand that in to a 8x6 grid, that is where it has to guess the colors and what to do. This is where you can get into a lot of problems as it depends on the intelligence of your tv - but even most modern ones still are rubbish at handling this - again, you are much better either using native resolution, a smaller resolution of the same aspect ratio (which can still lead to problems) or simply a smaller resolution and disable any sort of stretching.

Next, how good is the tv? Many older DVI ports on tv were simply there "because they could" not because they are good - the signal quality was lousy and there is simply nothing you can do about it.

Lastly, on a similar topic, what is the specification of your tv? I have seen a lot of problems on 1080i/720i (not p) monitors, the technology used to expand the image is just terrible. Again, there is nothing you can do.... You may get lucky if your tv has a "computer mode" option, this can usually help.

Modern TVs are a lot better, they are built for a computer - or, you can just output at 1080p through HDMI and get a rock solid image.

Sorry to give bad news - as I said, check for the option of a "computer mode", "fill options" or similar, but you may be out of luck.

Answer 2

PowerStrip is always worth trying when using rather 'exotic' displays on a computer.

PowerStrip provides advanced, multi-monitor, programmable hardware support to a wide range of graphics cards - from the venerable Matrox Millennium I to the recent ATI R7xx series. It is the only program of its type to support multiple graphics cards from multiple chipset vendors, simultaneously, under every Windows operating system from Windows 95 to the x64-bit edition of Vista. A simple menu that pops up from the system tray provides access to some 500 controls over your display hardware, including sophisticated color correction tools, period level adjustments over screen geometry, and driver independent clock controls

PowerStrip is shareware, fully functional and you can test it for free during a 30 days trial period.