Transparency effects in SNES and Genesis games via composite video artifacts
nerdlypleasures.blogspot.com
nerdlypleasures.blogspot.com
An emulator outputting 100% perfect RGB pixels onto an LCD screen is very different than running an analog RGB output to a CRT television.
I have a PVM-2530 CRT, and a hand-built Multi-AV to PVM-CMPTR adapter board ( http://i.imgur.com/EgCX2EJ.jpg ), and the colors still blend perfectly fine in his example of Kirby's Dream Land 3, as well as the more odious test case of Jurassic Park's translucent menus.
CRTs don't have an "official" horizontal resolution .. the number of RGB columns is dependent upon the tube and its size, and there's never an exact match against the analog nature of the RGB output from the SNES to the columns on a TV. So the colors naturally bleed together and produce the desired translucency. Maybe just a touch less severely than composite, but well more than enough to achieve the desired blending effects -- without all the horrific composite video artifacts.
Further, my SNES emulator simulates this effect as well, by choosing "Video Emulation -> Blurring." It doesn't quite work the same way as a CRT would, but it simulates the effect very nicely. It's not yet connected for my Genesis emulator, but that's only because it's very new and has more pressing issues to address, but it'll be there in time as well.
I can't speak for how these effects look on an XRGB-Mini (I haven't tested these types of translucency tricks on mine yet), but I would venture a guess that it would not even look close to as 'pristine' (striped) as the emulators output: it's still having to use an ADC on the RGB lines, and that's always going to be lossy to some degree.
I don't see the article suggesting otherwise. It suggests that some of the artefacts inherent to composite video encoding are not present in RGB.
I agree that the effect varies depending on the tube and the device, but in general I've found the blurring to be more pronounced in composite encoding, not to mention having a distinct quality.
Here are actual frame captures compared: http://www.chrismcovell.com/gotRGB/rgb_compare2.html
You also need to account for blooming, phosphor delay (different for each of red/green/blue), a "black" that is grey...
If you want faithful emulation, you need all these things. If you want performance, you want none. For the most attractive display, you need SOME of these things, and it varies from game to game. Probably some can be done in a GPU. You might want to let the user know if a real (not just MesaGL) GPU is available and able to handle something, if a GPU can do a half-good job, if something will just munch CPU time, etc.
The monitors looked grey even without being plugged in.
To be clear, this is tube technology, which was widely used right up to the end of the last century. Screens were often thicker front-to-back than they were wide. They were really heavy too, with thick leaded glass (to stop X-rays) at the front and big copper magnet coils at the back. There was a fine-pitch metal grid inside the glass, and some phosphors printed on inside of the glass. That stuff wasn't black. In operation the situation got slightly worse, from stray electrons probably, but fundamentally the displays just couldn't ever be black. It's the same as printing on brown paper: don't blame the settings of the printer when you don't get any white.
Are we to say that the black level of an OLED display isn't black because external light can raise it through reflection?
I'm jealous of your PVM-2530...I tried for years to get these in the late 90s/early 2000s and they just weren't obtainable near me and now they're mostly priced out of orbit in good condition. There are some other options, but they're all reasonably expensive for what they are.
The situation for real arcade monitors is looking even worse with the commonly available new stuff mostly being shit. Soon to be unobtainium, it looks like, and to me that's sad.
For now I have to settle for this tiny old Atari ST monitor...but hey, it'll sync down to 15.7Hz!
The first one shipped and had massive geometry and brightness problems. Every few minutes the entire screen would flicker -- like the image would zoom in by 5%, zoom out by 5%, repeat -- really disorienting. I took it to a local place that actually repaired them. Guy charged me $200 to replace some voltage regulators. It fixed the brightness but the image still flickered every few minutes. He wouldn't touch it again unless I paid him again.
Then I found a guy two states over selling two of them for local pick-up. Drove eight hours each way, got them loaded up and taken back. One of the two had the flyback transformer failing, and had a massive gauss problem at the top of the tube -- degauss only barely helped it, and it'd come right back every time. The other one seemed to be in good condition. I don't know how long it will last, and I always feel a bit guilty using it, knowing I'm wearing down its remaining life.
The 2530s set me back around $700 for all three plus the failed repair attempt.
I do also have a working 2030, and two 1390s. The 1390s are too small to be usable, but I can put them up on my plant ledge, so I'm keeping them for posterity.
If you don't have space, throw them away of course, no worldly possession is worth hassle in itself. But if you keep them, their value as cultural artifacts will continue to increase. Also with time, more people will be willing to pay the (high) cost of rebuilding them. I predict there will be at least one canonical company in the US which will spend many, many years rebuilding CRTs for collectors, enthusiasts and museums.
I listed them on eBay as defective along with a detailed description of their issues, and they were both purchased by some sort of museum place in New York I forgot the name of. They sent a truck out to my place to pick both of them up.
With 4k resolution you could probably have a really nice CRT emulation with dots like the phosphor on CRT.
The truly limiting quality issue is that the contrast of LCD monitors doesn't even come close to that of a CRT.
It's really quite amazing how much we acclimate to the inferior contrast of LCD displays. But if you ever run the output to both a CRT and LCD side-by-side ... it'll truly shock you what a difference there is.
I've yet to see an OLED PC monitor in person. Hopefully they're a lot closer.
In any case, it's unlikely that blurring was always intended. The article shows a screenshot from Chrono Trigger where a dithering-style checkerboard pattern is instead used to represent the keys of a typewriter. It would be difficult to tell what it was supposed to be if there was enough blur to hide dithering. Official artwork from NES-era Nintendo often showed characters drawn in a sharply pixelated style. And portable systems used LCD displays with no blurring, but dithering was still used extensively.
From what I recall (it's been a long, long, time since I've studied this) PC monitors were a typical square grid layout, much like how LCDs are. Where as TVs had the odd and even lines offset by half a pixel - a bit like a hexagon grid.
But I have to say, I don't think "designers" back then thought much about hardware setups different from their own!
It was different times and stuff had to ship fast, fast fast.
Great efforts were made to extend the Atari 2600 emulator, Stella, to deal with the imperfections of CRT displays that games of yesteryear depended on. Ian Bogost, co-author of "Racing the Beam" (https://mitpress.mit.edu/books/racing-beam), lead a team to make a code contribution to Stella that attempted to emulate the visual qualities that CRTs exhibited.
"...In Spring 2009, I tasked a Georgia Tech Computer Science capstone group to modify Stella, adding settings to simulate the CRT behaviors described above. The group consisted of five committed and talented CS seniors: Edward Booth, Michael Cook, Justin Dobbs, Will Rowland, and Prince Yang..."
The reasons portrayed in the article are exactly why I prefer this setup over RGB.
You're asking the wrong question. It's not blurrier in the RGB version. The point is that the graphics were designed for a blurry display method, so by not being blurry, the RGB version has a worse result.