When NTSC filter is mandatory?

[Ranmori]

@alexb3d

Something similar happens in PC-98. Pixels blur and generate new colors, red and blue tones change.

Keep in mind that this is a camera shot of CRT. It will inevitably be bluish. Thus, the color will appear to change quite a bit.

This is how it looks without shaders in Neko Project Kai II, and how I customized the shaders to take into account the “PC-9801 hardware-specific output” and “PC-9801-specific CRT performance” to make it look similar, and this is the actual difference. The colors do indeed change… By the way, it is 8500K.

I remember that the CRT for PC-9801 was not only 9300K but also over 10000K, but when it came to PC-9821, it was adapted to Windows and settled down to 8500K.

[hunterk]

do you have a native-res, unshaded screenshot we can play with?

[Jamirus]

Ofc, here:

Or try this Atari shot. Ideally grass is green and water blue, though it’s also ok if it’s more brownish / purplish, real hardware has variance and I suppose it requires tweaking as well.

[hunterk]

Looks like artifact colors will work for borrowed time if you take off the pre-scaling passes:

and ultima 4 has some color if you double its horizontal res, though the water is magenta instead of blue…

[DariusG]

@DariusG

I believe every system created it’s own style of artifacts…

NTSC Apple II didn’t exhibit dot crawl so a generic NTSC/composite shader for everything is not entirely accurate. Or maybe even missing colors in this case, etc.

240V Platinum Apple IIe 50Hz NTSC colour demo

[alexb3d]

I’m leaving for a moment and everything happens here, with you people you can’t even sleep.

Recently Ranmori shared with me ruuupu1’s twitter which has good pictures of PC-98 monitors and some TVs. Looking for information on the models I got this article Pixels are not Square on the selectbutton forum with many detailed images.

I also got the minuszerodegrees page with technical information of all video modes (?), maybe it will be useful.

I have discovered some things…

Pretty sure I’m wrong, color is not produced from an MDA/Hercules adapter in B&W to a CGA monitor. It is a function of the CGA adapter to convert any B&W game to color. This is produced with composite mode.

When the CGA adapter is selected in PURE, an option to enable/disable composite mode is enabled.

@Jamirus

would guess that Mame HLSL is the most accurate

Apple also used artifact colors?
It has been impossible for me to get this effect with that shader, I have tried with DOS games in B&W. Did you do anything special?

@hunterk

Looks like artifact colors will work for borrowed time if you take off the pre-scaling passes:

I don’t understand this, how do I do it?

With the “artifact-colors” shader that @DariusG shared if I can get the effect. And by adjusting the HUE a bit (+/- 12), you can get a similar color.

original image / with CGA compositor activated
image with shader artifact / with HUE set.

The artifact colors effect can be achieved on B&W images, and on CGA images, which is what the PCJr, Tandy and tuned CGA mods do.

Composite output and off / composite on / shader.
RGB-CGA / composite activated / shader output.

I once saw a video of this game on a real monitor and the gentleman said, “that’s what it looks like in game not magente”. (the last image).

original image / with CGA compositor activated
image with shader artifact / with option F Col at 0.50

CGA has a two-color high definition mode, it is B&W similar to Hercules but is not compatible with composite mode.
The game Planet X3 es del 2018, seems to be a rather strange experiment, it supports several CGAs, including the 2 colors.
2 color / composite mode activated / shader with F Col at 0.50.

The output the PURE produces is good, the shader does a few more tricks, I think with some color adjustments it may be a better choice, at least on PC.

@Ranmori

Keep in mind that this is a camera shot of CRT. It will inevitably be bluish. Thus, the color will appear to change quite a bit.

I had not thought of this. The color is affected, but why blue?
Do you know what camera it has…if it is professional it has compensation, from the lens, I suspect it is a phone. Maybe it has some automatic adjustment because I was measuring the ambient levels and they seem correct.

I can’t do much with the temperature, if I don’t have the one the camera uses, it would be great to adjust the colors automatically. Or if I took the picture with grayscale guides. Or some simple visual reference to get the most true color. I’m going to ask him to see what he says, just one photo is enough.

[Ranmori]

@alexb3d

I had not thought of this. The color is affected, but why blue?

Recall that high color temperature is the standard for Japanese CRTs.
Since Japanese “retro games” are designed on the premise of high color temperature (like SMB on NES/FC), the Japanese are supposed to keep the bluish color when shooting with a camera.

I simply don’t believe that the camera automatically adjusts the color temperature (I should add that Japanese cameras also have a high color temperature).

I also think it is because Japanese people, like this Twitter(X) he, have this color temperature as their standard.

@alexb3d

Pixels are not Square

I remember the Sharp X68000 was that. The aspect ratio is 1:1 with a maximum of 1024 x 1024, but the sub-pixels are slightly extended horizontally to 4:3.

I’ve heard similar stories about this for MSX as well; the exact aspect ratio for MSX was taken by Screenshots with RA, imported into Photoshop, and the resolution with the margins cropped out does not match the resolution of the MSX standard.

[Jamirus]

Very interesting. Having trouble to get it to load without loading the stock passes, substituting them with something else or just loading the three last passes manually fails to load the preset.

Ultima IV is a bit tricky with HLSL also, if you use the NTSC-MD Rainbow preset and set scanline duration to 46.9, it will also look green/magenta like, but by decreasing "NTSC incoming Phase Pixel “Clock Scale” and/or raising NTSC B, you can get the water more to blue on one side, the grass also changes to a orange tone on the left. Pixel clock scale 20:

How to prevent this and get it to be consistent?

@alexb3d For PC, you need to set “scanline duration” to 44.7 in HLSL. NTSC Value A is 0, with NTSC Value B the colors change, though it doesn’t end up looking like Dosbox or the shot at Moby of Fooblitzky, needs more tweaking, e.g. try Outgoing Phase offset" parameter.

[c9f5fdda06]

it’s all nostalgia. It’s why some of us who obsess over shader accuracy don’t get that people just want what they remember as kids – like many things in life.

[alexb3d]

@Ranmori

the Japanese are supposed to keep the bluish color when shooting with a camera.

The cameras have 6500 as standard, it is the one that has the best balance with the lighting of the environment. If the camera of the photos has high temperature, and the monitor also, then the colors are not affected, it will affect the environment, the room, which should be around 6000.

If you have a 6500 camera and the monitor is 9000, it will look redder.

Anyway it is something easy to solve, the difference between 8500 and 9000/10000 is slight, and it will vary with any change of contrast in the LCD that emulates it. But, I’m still going to check the original palette against the images, to look for the best fidelity.

I’m more concerned that I have some filter on, or auto white balance, this defines the temperature. I am also concerned about how old and worn the monitor is, that affects the colors more.

Overall I think the images are fine, lowering the red tones is native to CRTs.

The Pixels are not Square post I haven’t read (I should), I shared it because there are many detailed images of CRTs.

@c9f5fdda06

it’s all nostalgia.

Nostalgia is the result of a process of ‘habit’. It has little to do with ‘retro’. Humans define memories by generating neurological patterns, these are built up over a long period of time and can last a lifetime.

It may have happened to you that, your favorite singer releases a new album, you love a song, 2 months later he starts his concerts and you go, when he sings the song he changes it, he interprets it in a different way and you think “it’s ok but it was not what I expected”.

It’s the same thing and the more time goes by the worse it gets. If you last 5 years watching this.

You open an emulator and see this, the brain naturally rejects it.

And of course the new shaders are much appreciated, but in some cases it is a reinterpretation, rather than a perfect rendering.

[hunterk]

OTOH, our memories can do weird stuff. We get tons of people who come here claiming CRTs don’t have visible scanlines, or that rolling scanlines are a thing.

My old creative writing professor used to say “nostalgia is less a way to remember and more a way to forget”. (I don’t think he came up with that, but I can’t recall who said it first)

[alexb3d]

Memories are inaccurate, they re-edit over time and are tied to our mood, plus we have a ‘retro fashion’ that blurs everything.

Of course, there are shaders of all types and CRTs could vary a lot for many reasons, but, my comment is for these cases in particular the difference is very noticeable.
There is a lot of contrast in a CRT slotmask, old and used, connected by RF to a PVM shader with the precision of a LCD/Led TV.

So why does it happen so much, they are not isolated cases, I can imagine that it is an effect of the inaccuracy of the memory, maybe some characteristics of the CRT cause people to think that the scanlines are rolling.

Now, thinking a little, I have a giant LG cinemaster (from 98), I’m trying and I can’t remember the scanlines with Sonic on this TV. I can’t test now, when I get a Genesis I will try.

A side note, on TVs and Monitors you can totally eliminate the scanline, VGA monitors have some user manipulable options and TVs have several internal knobs, especially the ones next to the flyback, that can be removed. If my memory does not fail (irony) it is something similar to what lottes-multipass hardScan does.

[DariusG]

That’s because mostly watching TV shows on regular 576i/480i, or having some 480i system like n64-Dreamcast lol. Or used some 288p like the Amiga on 13" low tvl. So they come up with “TVs have no scanlines”. If you use a 20" on a 224p/240p they are very very much visible, they are huge lol.

[hunterk]

I believe much/most of it is just: we understood what the image was supposed to be, and CRT technology was both ubiquitous and the only option around, so our brains saw what we expected: a solid, unbroken image.

I’ve seen people swear typical arcade monitors didn’t have scanline gaps, and I know that’s not true, since I own a monitor from the period, but in my memory, they’re not there, either. The images were solid in my mind.

I spent a lot of time in arcades as a kid and I was still baffled by the first “scanline” filters in early emus. I didn’t understand what they were trying to communicate.

[Drybonz]

That’s weird because, in my mind, the scanlines were an integral part of how I remember the arcade and console images from that time. If I set up a shader I can take out curvature, color distortion, bleed, etc… but if I cut out the scanlines I no longer have the feeling of the games from that time.

[JHorbach1]

I believe this perception is mainly due to the size of the TV each person uses. Here in Brazil, our TVs were rarely large, especially those that parents gave to their kids for gaming. So, I really don’t remember seeing scanlines. In fact, I still have my TV, and it doesn’t display scanlines at 240p because it’s too small.

[Drybonz]

Maybe… but arcade monitors were the same for each game, so that wouldn’t explain the polar opposite perception Hunter and I mentioned, above. Not to mention I played on a spectrum of monitor sizes for the console years. I, personally, think it’s just a matter of what you noticed when you were a kid playing those games… I’m sure there’s some science in it, but I’m not the guy to ask about that.

[hunterk]

Yeah, I’m the same way now

My point was really just that memories and nostalgia are poor guides, which is funny because that’s a large part of what brings us here in the first place.

[Drybonz]

Yeah, it’s a pretty personal thing.

[Jamirus]

Lol, I just found it out: the value of the second stock pass in the artifact color preset says 640, if you change it to an appropriate width of the source (here 560 for Apple and 672 for Atari) and then change the hue parameter, you can get appropriate color.

With HLSL things are really a good deal more complicated…as Atari apparently needs precise scanline duration of 46.93, which you can’t do from the gui, or /and modify the color carrier which is also not really recommended to do from the RA frontend shader parameters because it only shows you two decimals. The Atari 800 core thankfully has the basic artifacting options now integrated