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NFG Forums => RGB + Video Discussions => Topic started by: mr. newbie on November 28, 2005, 04:08:06 PM

Title: plasma tv's and 15mhz
Post by: mr. newbie on November 28, 2005, 04:08:06 PM
hi i believe Endymion said he had a plasma that did 15mhz. i know that if i want rgb i needsomething  that suports that. do a lot of plasmas support 15mhz? can i use them for rgb from my ps2 or xbox?    
Title: plasma tv's and 15mhz
Post by: NFG on November 28, 2005, 04:16:20 PM
You'll have to check the specs.  Many plasmas, especially the cheap ones, only do 31kHz through RGB ports.  The existance of a 21-pin SCART socket is a good clue.  If it only has a VGA port or a digital port you may be out of luck.

It'll look like ass regardless, the purity of RGB is wasted on plasma & LCD screens, sadly.
Title: plasma tv's and 15mhz
Post by: TJ_Kat on November 29, 2005, 03:32:45 AM
I'm sure you explained it before Lawrence, but could you re-explain why RBG is wasted on plasma and LCD? (something tells me I could use the search all day and not find where you mentionned it before).
Title: plasma tv's and 15mhz
Post by: Endymion on November 29, 2005, 03:44:00 AM
As was said--you need to look at the specs for the screen you are dealing with. Every manufacturer is different. Even the different models they make may do different things. In my case, the screen I have is really not a TV, rather it is a commercial "monitor," similar to the RGB monitors that a lot of us scour ebay for. The difference is that it is a plasma screen, it does VGA, and it can do HDTV resolutions. This particular monitor does not have SCART. It has Y-Pb-Pr via BNC and a VGA DB-15. But both of these connectors can accept 15KHz RGB. All I have to do is change a setting with the remote control and the Component adapter can switch to RGB or VGA.

I don't think it looks terrible either, the colour is as pure as you want it to be. It's as sharp as I've seen it on any CRT as well; it definitely does not look as nice as a VGA signal or an HDTV signal at 720 or 1080, but it looks as well as I would ever expect an RGB signal to look.
Title: plasma tv's and 15mhz
Post by: NFG on November 29, 2005, 09:08:37 AM
When an RGB monitor deals with a lower or higher resolution signal it spaces out or compresses the scanlines accordingly.

Fixed-resolution screens, like LCDs and plasmas, cannot stretch their scanlines.  It's fixed, and the only way to make the image slightly larger is to basically sample the image and stretch it using software to fill the space.  

This results in a much blurrier image than I'd prefer, and the additional processing can result in other undesirable artifacts, like excessive sharpening or contrast adjustments washing out some colours.  In extreme circumstances this capture-and-muck-with procedure can introduce significant delays between the signal source and the TV's output - irrelevent when you're watching a movie, but a 2/60th of a second delay for gaming throws your timing right off.  Some 100Hz Sony CRTs are known to do this.

Basically anything that fucks with your signal degrades it.  Sampling and resizing is a lot of fucking-with, so your signal runs the risk of being significantly degraded.
Title: plasma tv's and 15mhz
Post by: Guest on December 06, 2005, 03:29:01 PM
hmm thx for all the help. i dont think i'll get a plasma now since my neighbor is selling his arcadecab. that should be 15mhz.
Title: plasma tv's and 15mhz
Post by: Endymion on December 07, 2005, 12:29:57 AM
15KHz. ;)
Title: plasma tv's and 15mhz
Post by: Guest_Martin on December 09, 2005, 05:42:27 AM
QuoteWhen an RGB monitor deals with a lower or higher resolution signal it spaces out or compresses the scanlines accordingly.

Fixed-resolution screens, like LCDs and plasmas, cannot stretch their scanlines.  It's fixed, and the only way to make the image slightly larger is to basically sample the image and stretch it using software to fill the space.  

This results in a much blurrier image than I'd prefer, and the additional processing can result in other undesirable artifacts, like excessive sharpening or contrast adjustments washing out some colours.  In extreme circumstances this capture-and-muck-with procedure can introduce significant delays between the signal source and the TV's output - irrelevent when you're watching a movie, but a 2/60th of a second delay for gaming throws your timing right off.  Some 100Hz Sony CRTs are known to do this.

Basically anything that fucks with your signal degrades it.  Sampling and resizing is a lot of fucking-with, so your signal runs the risk of being significantly degraded.
CRTs can also fuck with your signal by the very method that they use to create the picture, with perfect geometry being impossible on ANY crt, and all CRTs "breath" sadly, meaning that the majority of films with dark scenes and flickering candles/lightening strikes, resize visibly before your eyes every time there is a small increase in brightness.
It all depends on what you preffer.
I personally would rather have the perfect geometry of a plasma as akthoiugh I am amazed by the perfect clarity of RGB on a CRT it does... get on my nerves when the HUD in games bends as fluctuations in brightness on screen occur. :huh:  
Title: plasma tv's and 15mhz
Post by: mr. newbie on December 14, 2005, 10:17:37 AM
well i went to look at the arcade cab again and it has very serious burn in issues. i'm gonna try with a commodore 1084.