vertical vibration in TFT screen around moving objects

[Marius]

Hi!

 

Sorry for starting another TFT television related topic.

I'm pretty unknown in this subject, and I don't know the right official words for certain issues/problems.

 

I could describe.

I have a 28" Samsung TFT screen. The Video Composite is medicare and I find the screen not very usable for atari 8bit, especially where fine scrolling is used (are there ANY TFT screens that give (almost) the same quality in fine scrolling like it is on CRT?)

 

Ok but now the question.

 

Next to the downsides with fine scrolling I found another -much more- annoying issue.

 

On a static screen there is NO problem. So the blue BASIC screen looks real crisp and is usable. Just like other screens like The Last Word or Chaos Music Composer. All great.

 

But as soon something moves on the screen the scan lines around that moving object do vibrate (!) (they move up and down very fast; it is hard to notice if you look from a distance, but when you are closer to the screen it is something that is seriously noticeable and extremely annoying).

 

This is not something related to output quality of the atari I guess. This atari has a brilliant screen output.

 

Is this a known issue? Is it fixable? Which TFT does not have this (is this something I can check on the specs of such a television) And I like to repeat my question: are there TFT screens that do the Fine Scroll really good (and again: what are the specs to check for?)

 

Lot of questions… I hope someone can help me -especially with that vibrating scan lines)

 

-> oh and it remarkable … not the entire screen vibrates, just the scan lines around the moving object.

 

[flashjazzcat]

It's lag in the analogue/digital converter. I have a few screens where this effect is evident. The effect is often much worse when you use a VGA upscaler or similar.

[Bryan]

CRT! CRT! CRT!

[Marius]

Yes CRT is the only choice for a8!

 

I am building a stock of small bedroom television sets, but man… even those small CRT's take a lot of space.

[Gunstar]

It's lag in the analogue/digital converter. I have a few screens where this effect is evident. The effect is often much worse when you use a VGA upscaler or similar.

This is a disappearing issue with newer converters and upscalers (both integrated and stand-alone), even many of the cheap Chinese products are finally getting better and faster silicon.

 

That being said, I still use CRT with upgraded chroma-luma circuits in my 8-bits. At least as long as my 1084 monitor works.

Edited April 18, 2015 by Gunstar

[phaeron]

This effect is caused by the TV not correctly recognizing non-interlaced video. Like many computers of the time, the Atari produces a non-interlaced picture of 262 scan lines at 60 frames per second instead of 525 scan lines at 60 fields per second. What modern TVs tend to do is just pretend that the video is interlaced. For static screens it's fine, because the deinterlacer in the TV undoes this fib, and you get the same picture. When stuff moves, you get the artifacts because then the TV is treating the frames as fields, causing jitter when the same graphics are displayed as even or odd fields.

 

Although it doesn't cause the vibration you're seeing, motion interpolation can also cause artifacts on moving graphics. It's known as Auto Motion Plus on Samsung TVs, and it can be turned down or disabled as long as you're not on one of the preset modes (Game, Cinema, Sports on the one I have).

[Faicuai]

The cure:

 

http://atariage.com/forums/topic/212422-my-800-looks-like-crap-on-my-viewsonic/?do=findComment&comment=2756165

 

Enjoy!