NTSC Color Palette - CRT TV Default & Tuning Varieties

[Trebor]

Here's a good demonstration on the "warm-up" difference in palette colors. First three captures are taken with the console just powered on from cold and running less than 5 minutes. The next three that follow those are from the same console after the system has been running for about 15-20 minutes. Dials as always are in the neutral/middle/default position in all photos.

 

I have captures with two different sets of shots from two different console. First set is from Best Electronics which uses a very simple composite mod with a few bridges and resistors pieced together.

 

Second set is from Yurkie which is a modification of the composite mod from Longhorn. Any picture distortion blur is mostly from the nature of the device and trying to capture a photo from it.

 

Honestly though, while the Best Electronics mod is decent, Yurkie's mod is much brighter and cleaner. The Best Electronics mod has very noticeable color bleed and ghosting. Yurkie's looks near to S-Video in quality; seriously, it's awesome.

 

Regardless, you will notice that despite two totally different consoles the outcome is the same with just one console brighter and clearer than the other.

 

Best Electronics composite mod:

 

Yurkie composite mod:

 

I hope these captures and explanations helps people both with composite modifications and in understanding the palette I am striving for. Ideally MESS is best for this as you start with the RAW video output and fine tune until your heart is content. However, ProSystem is popular and used by many in the community, and I am striving to now provide a palette which best reflects a 7800 on a CRT when the console has "warmed-up".

[gorfcadet]

That is crazy how green turns brown once the system warms up! Is there a green that stays green or will all shades suffer some "warm up" effect?

[Trebor]

It's not even just a brown that leans green, but a brown that leans red...lol.

 

From the color chart, I believe the ones most noticeably impacted are the colors in the $1 & $F region (maybe even a little $E (?)).

Colors in $C & $D are likely fine though or the impact is not as obvious.

 

I don't have a CC2, but down the road with a Harmony 2, I'll be able to run the color demo ROM and have a more definitive answer.

 

Morale of the story is if you a running a 7800 on a modern TV for just a few minutes you are seeing the worst possible palette under the worst possible display conditions (A double whammy). Running a 7800 for a while on a CRT and the system palette really shines at its best.

[gorfcadet]

I'll keep that in mind as I get back to my projects! That is a huge help. I really want green to stay green after all!

I wonder if there is something that can be done to the 7800 itself to keep it from doing that.

Imagine porting a Teenage Mutant Ninja Turtle game to the 7800 and the turtles all turn brown in 20 minutes!

[Trebor]

While more CRT palettes are being worked on - I had to start work on an "LCD" one as well:.

 

Kevin, let me know what you think regarding the LCD colors below:

 

 

I should have everything complete later this week for this LCD palette and the CRT ones.

[KevinMos3]

From eyeballing it Treb... that looks pretty dead-on to me.

[Trebor]

For reference and archiving purposes linking THE END.

 

Even better and more direct...HAPPY EVER AFTER

[bigbacon]

what is the fix then on this?

 

my composite mod 7800 has browns being green on my LCD tv. the console is hooked up through dvd recorder and then that goes into the tv.

 

I can mess with the tint control on my TV but it is still never correct. closed but not. Games like fatal run look weird or things are all the same color when they souldn't be.

Edited January 13, 2016 by bigbacon

[Trebor]

what is the fix then on this?

 

my composite mod 7800 has browns being green on my LCD tv. the console is hooked up through dvd recorder and then that goes into the tv.

 

I can mess with the tint control on my TV but it is still never correct. closed but not. Games like fatal run look weird or things are all the same color when they souldn't be.

 

This was relatively recently brought up in another thread. For convenience, the details are re-posted below:

 

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Does this symptom only show on AV modded systems, for this game specifically?

 

There are two different items at play here without adding the quality or a possible issue of an A/V mod into the mix:

 

1. The aforementioned color phase shifting*. This does not affect "Commando", as that game uses a $1x value for its ground color. Color phase shifting has zero impact on the $1x values. Color phase shifting does significantly impact other titles though, such as "Choplifter" for its ground color and the enemy birds in "Joust"; both utilize a $Ex value. Color phase shifting biggest visual impact is on the $Ex and $Fx values.

 

2. Default hue/tint setting of various display screens. This directly impacts the $1x values (I.E. Commando ground).

 

Many NTSC CRT vs. many modern displays have a default setting that balances slightly differently compared to one another:

-NTSC CRT = ‘Slightly’ more red towards green, less red towards blue. 'Traditionally' interpret this as overall 'more red' with a tint/hue setting feature.

-LCD/LED/Plasma/Etc. = ‘Slightly’ more red towards blue, less red towards green. 'Traditionally' interpret this overall as 'more green'.

 

Additionally, there are some color palette values that are closer to transitioning to a ("significantly") noticeable different color than other ones.

 

The slightly changed hue/tint setting effect is seen on other platforms as well; for example, the sky in Super Mario Bros for the NES. Many displays, mostly CRT, will show it as a 'true' blue, while most other displays, modern ones, show the sky leaning more towards purple. The ground in Battletoads is another good NES example. Some displays, mostly CRT, show an abundance of brown clearly throughout, while other displays, particularly modern ones, display it more as a mostly green ground.

 

Various hard coded palettes for emulators try to either reflect and imitate the resulting CRT colors or the modern display colors, or some hybrid combo.

 

...I know with 100% certainty that both hue pots on my 7800 are properly calibrated, because I tweaked them myself.

 

The pots often referenced inside the Atari console adjust the degrees of color phase shift, instead of the hue.

 

A factory tuned console may be set to a color phase shift of ~25.7 degrees (Visual $1x matches $Fx); ideally reaching ~26.7 degrees (All unique colors - 128 for A2600 & 256 for A5200/A7800) when warmed up, but typically goes as high as ~27.7 degrees ($1x matches $Ex & $2x matches $Fx) when running consistently longer. When "cold" it's ~24.7 degrees.

------------------------------------------------------------------------------------------------------------------

 

*Edit added link to: 7800 Development Wiki Color Documentation.

[Andromeda Stardust]

Thanks for the write up. I've kind of accepted that Commando, while having great gameplay and the best soundtrack on the system (excluding homebrew), the muddy sprites and colors in this game just look like ass.

[Trebor]

Thanks for the write up. I've kind of accepted that Commando, while having great gameplay and the best soundtrack on the system (excluding homebrew), the muddy sprites and colors in this game just look like ass.

 

Shame that's the case for some (many?) modern displays. On a CRT though and under some modern displays it looks great.

 

Other examples - incorporating Composite Mod(s):

 

CRT

Not adjusted LCD

Same LCD Adjusted

 

EDIT: Here's my personal example from a few years back utilizing the same console in both scenarios.

 

First set on a CRT, then next on an LCD without making any adjustments:

 

[78001987]

I wish there was a way to hard-wire the 7800 board to be at the correct color shift right at power up. or develop an on-board tint/hue knob to help people who use LCD and other modern TVs so they don't have to adjust their set (and mess up other consoles and BD/DVD/Cable displays)

[Andromeda Stardust]

 

Shame that's the case for some (many?) modern displays. On a CRT though and under some modern displays it looks great.

 

Other examples - incorporating Composite Mod(s):

 

CRT

Not adjusted LCD

Same LCD Adjusted

 

EDIT: Here's my personal example from a few years back utilizing the same console in both scenarios.

 

First set on a CRT, then next on an LCD without making any adjustments:

 

CRT1.pngCRT2.pngCRT3.png

LCD1.pngLCD2.pngLCD3.png

Do you think it's possible the Best installed AV mod could be tampering with the signal in such a way that Commando looks like ass on my mom's CRT but all my other 7800 games (including Tower Toppler) look fine?

 

I really need to take photos...

[Trebor]

Do you think it's possible the Best installed AV mod could be tampering with the signal in such a way that Commando looks like ass on my mom's CRT but all my other 7800 games (including Tower Toppler) look fine?

 

I really need to take photos...

 

That's a strange scenario. One game (Commando) being 'off', would usually lead to believe there's an issue with the cart. However, not sure how possible that would be either in harmony with the results mentioned...It's very odd. Weirder things have happened though.

[bigbacon]

try fatal run. everything brown is green and everything yelllow is mostly green as well.

 

I didn't notice my issue with colors too much until this game. I'm on a LCD tv with my consoles going through a sony dvd recorder.

 

i can mess with both the pot and tint on the tv but it is never perfect.

 

Does this issue still happen if the console is modded for svideo? guessing not as my other 7800 using RF does the same thing.

 

EDIT Again:

 

KNow what....I adjusted the tint on my TV to -7 and on other consoles, including my Jaguar and TG16 the color difference is very small. I can barely tell in temptest 2000 or Neutopia. It might actually even be better.

 

It seems on my tv if I have tint at 0. All yellows seem to have a green hint to them.

Edited January 14, 2016 by bigbacon

[Trebor]

EDIT Again:

 

KNow what....I adjusted the tint on my TV to -7 and on other consoles, including my Jaguar and TG16 the color difference is very small. I can barely tell in temptest 2000 or Neutopia. It might actually even be better.

 

It seems on my tv if I have tint at 0. All yellows seem to have a green hint to them.

"Many NTSC CRT vs. many modern displays have a default setting that balances slightly differently compared to one another:

 

-NTSC CRT = ‘Slightly’ more red towards green, less red towards blue. 'Traditionally' interpret this as overall 'more red' with a tint/hue setting feature.

 

-LCD/LED/Plasma/Etc. = ‘Slightly’ more red towards blue, less red towards green. 'Traditionally' interpret this overall as 'more green'.

 

Additionally, there are some color palette values that are closer to transitioning to a ("significantly") noticeable different color than other ones.

 

The slightly changed hue/tint setting effect is seen on other platforms as well; for example, the sky in Super Mario Bros for the NES. Many displays, mostly CRT, will show it as a 'true' blue, while most other displays, modern ones, show the sky leaning more towards purple. The ground in Battletoads is another good NES example. Some displays, mostly CRT, show an abundance of brown clearly throughout, while other displays, particularly modern ones, display it more as a mostly green ground."

 

[bigbacon]

"Many NTSC CRT vs. many modern displays have a default setting that balances slightly differently compared to one another:

 

-NTSC CRT = ‘Slightly’ more red towards green, less red towards blue. 'Traditionally' interpret this as overall 'more red' with a tint/hue setting feature.

 

-LCD/LED/Plasma/Etc. = ‘Slightly’ more red towards blue, less red towards green. 'Traditionally' interpret this overall as 'more green'.

 

Additionally, there are some color palette values that are closer to transitioning to a ("significantly") noticeable different color than other ones.

 

The slightly changed hue/tint setting effect is seen on other platforms as well; for example, the sky in Super Mario Bros for the NES. Many displays, mostly CRT, will show it as a 'true' blue, while most other displays, modern ones, show the sky leaning more towards purple. The ground in Battletoads is another good NES example. Some displays, mostly CRT, show an abundance of brown clearly throughout, while other displays, particularly modern ones, display it more as a mostly green ground."

 

 

what is interesting is with the 7800 the change is VERY dramatic, every step in the tint setting shows a major change in the color. Everything else, even my NES, the change was very small and almost not noticable.

Edited January 14, 2016 by bigbacon