LCD/Plasma/CRT/DLP - more questions

[gIzzE]

They just show what is what, there is no upscaling as there is no fixed resolution.

However, CRT displays are adjusted for size and position for each frequency, so feed it 480i 15khz and set it up and then feed it 480p 30khz and you will need to adjust the size and position again.
But this is done at the factory for domestic displays.


In the case of games the developers simply fill the gaps between 480 and 576 with black, hence why you get the borders.
Sometimes developers add in the extra, but very rare until later systems.

480 is softer than 576 because you have thrown away 17.5% of the detail, nothing to do with being scaled.

[danstan21]

Right, okay, thanks. I think I understand that. Obviously I understood why 576i would have more detail than 480i; there's just more picture

Just to be sure, I'd like to put the question into context. Assuming identical connections, is there any difference in the picture quality between F-Zero GX running at 480i on a PAL CRT set compared to the same thing running on an NTSC set? When running on a PAL TV, there is no black border around the game as it entirely fills the screen, as is the case with all GC games to my knowledge (played around 75 and it's never come up).

I'm sorry if the above was easily answered in your above post - I don't believe I'm very good at picking this stuff up.

[gIzzE]

Right, okay, thanks. I think I understand that. Obviously I understood why 576i would have more detail than 480i; there's just more picture

Just to be sure, I'd like to put the question into context. Assuming identical connections, is there any difference in the picture quality between F-Zero GX running at 480i on a PAL CRT set compared to the same thing running on an NTSC set? When running on a PAL TV, there is no black border around the game as it entirely fills the screen, as is the case with all GC games to my knowledge (played around 75 and it's never come up).

I'm sorry if the above was easily answered in your above post - I don't believe I'm very good at picking this stuff up.

I think the quick answer is, there is no such thing as a PAL CRT.


Any CRT can take 50 or 60hz, some TVs can not take NTSC because the colour decoder is PAL only and/or it has not been set up for 60hz refresh and sync/timing.

So the answer is 'makes no difference what so ever.'

[gIzzE]

PAL and NTSC are colour decoders.

50hz and 60hz is the refresh rate.

480 and 576 is the amount of lines.

You can have any combo of the above, a Cathode Ray Tube is not pal or ntsc, it is the electronics that drive it that decide that.

[EvilBoris]

Does and HD CRT differ from a regular one then?

[danstan21]

Okay, thanks very much for persevering with me. Certainly splitting up the three main bits there has helped me grasp this a little better.

I just have one final question then: if all three of those things are completely separate, why were PAL SNES/N64 games forced to run at 576i and 50Hz, given all the drawbacks that came from that? If you can have a PAL 480i 60Hz signal on any CRT with a PAL colour decoder, why was that not chosen?

EDIT: Sorry, this really IS the final question, you've really just got me curious at this point - I know that RGB is neither PAL nor NTSC, so is that a third, superior colour decoder to both of them? And is that the same as what a device using component cable outputs (I think it's called YbYpR or something)?

[EvilBoris]

Because most TVs sold in the UK were only setup to accept a 50hz Signal at 576i in the PAL colour format.

When when you tried to give them anything else they wouldn't display a working image.

[gIzzE]

It has a higher dot pitch, not to be confused with pixels, although similar I guess.

The finer the dot pitch the higher the resolution. You can feed a CRT with a dot pitch designed for say 800x600 with 1080, but it will start to look soft, and you may find that it can't handle the refresh as well, so although 800x600 at 120hz is fine, go to 1080 and it needs to be dropped to 30hz, plus you don't see any real benefit as everything passed the 600 lines is just lost, so it can look softer.

But I would guess all CRT displays can take 640 lines at 60hz no problem at all, so for pal and ntsc it is not an issue.

[gIzzE]

Okay, thanks very much for persevering with me. Certainly splitting up the three main bits there has helped me grasp this a little better.

I just have one final question then: if all three of those things are completely separate, why were PAL SNES/N64 games forced to run at 576i and 50Hz, given all the drawbacks that came from that? If you can have a PAL 480i 60Hz signal on any CRT with a PAL colour decoder, why was that not chosen?

Because not many manufacturers back in the late 80s and early 90s felt the need to add an NTSC colour decoder and so there was no real need to set the displays up to accept 60hz either.
I don't suppose anyone could think why someone would want 60hz signal with pal colour.

EDIT: Sorry, this really IS the final question, you've really just got me curious at this point - I know that RGB is neither PAL nor NTSC, so is that a third, superior colour decoder to both of them? And is that the same as what a device using component cable outputs (I think it's called YbYpR or something)?

I'll answer that in a bit. Got to nip out for some lunch!

[gIzzE]

PAL and NTSC are purely the colour decoders.
The term is misused to describe 576i vs 480i all the time.


Displays get their image by showing a black and white picture and then overlaying colour, the three primary colours are all you need, RGB, mix those up and you have every colour you need.

NTSC was developed to allow broadcasters to send the colour info over the airways.

PAL was the system Europe developed to do the same, there are too many issues with NTSC, it is a very weak system.

So pal, ntsc, secam etc. are just ways to combine the RGB data and send it as a single stream.



Component video is simply seperating the parts that make up the signal to keep them pure.
s-video seperate luminance and chrominance.
RGB separates the red green and blue and then sends the sync signal separately too, either sync on green, horizontal and vertical sync or sync on composite (euro scart).
YPbPr is analogue 'component' where luminance (black and white) image is sent on the Y signal and then the differences between red and blue vs the luminance on Y is sent on the others, which builds up the image.

All the above are actually component video signals, just that we started to call YPbPr component as it was far easier.

YPbPr was used as it used far less bandwidth than RGBs, without any perceivable loss. And it is a far better connector than the rubbish 21 pin Scart.
You don't have to send green as it can work this out from the PbPr part of the signal.

Most media is coded in YPbPr any way, so using it is no loss, and going RGB from a DVD player or something may actually be worse as it has to be converted from the YPbPr stored on the disc.
When they say PAL or NTSC disc there is no PAL or NTSC stored on it at all, the player is what will kick out PAL or NTSC, if you are using composite of course.



Now there are various forms of 'component' as we know it today. YPbPr above is when we are talking analogue.
You then have YUV etc.
All they are doing is talking about different colour spaces really, as long as the source and the display know which one they are talking to it makes no real difference.

YCbCr is the digital version of the YPbPr component signal, again, simply a way of decoding RGB info the same as the analogue version.

[danstan21]

That's incredibly informative; I've definitely learned a few things today. Thanks very much!

[Lyris]

It's 50hz yes. Any way to change the refresh rate manually?

Some older Samsung PDPs internally convert 50hz signals to 60hz for output - at least the ones I tested did.

This relates to the fact that 50hz flickers too much when output natively from an impulse-type display like a PDP. Why Europe didn't just scrap this stupid format when they moved to HD...

(See "Picture Quality" section in the review I did years ago here: http://www.avforums.com/reviews/Sams...74/Review.html )

The artefacts are caused by the standards conversion. I made a test pattern to replicate it which I sent them. Is this running the latest firmware? I guess they didn't change the behavior until the next years.

[gIzzE]

Some older Samsung PDPs internally convert 50hz signals to 60hz for output - at least the ones I tested did.

Many NEC PDPs did as well, and the early Pioneers converted everything to 72hz.

[wakka]

Learned a lot from that post Gizze, ty. I feel like I actually know what 'composite' and 'component' are referring to now, other than types of cable!

[Matt~]

Great post gizze, very clear and helpful

I have a Sony PVM-1442QM, and the picture flickers horizontally from left to right if it's given a 60Hz signal. I've confirmed it's not just the one particular Japanese console it's unhappy with, as when I switch a pal game like psyvariar or r-type final to 60Hz mode the flickering begins also. I've tried adjusting the V-hold knob on the back and this doesn't solve the problem. The consoles are plugged in to a Holdan HSR-1000 SCART router, and then into the RGB and sync BNC thingies on the monitor (see below)



It's supposed to be cool with NTSC - it has PAL, SECAM, NTSC and NTSC 4.43 on the front panel next to little blobs (see below) that look like they should light up accordingly, although mine never do.



Does anyone know how I might solve this problem, if possible?

Help would be much appreciated!