480i on BVM vs. 480p on PC CRT

[Flea46]

Hi all,

Currently owning a Sony BVM-14F5E as my display for 240p consoles, I've recently bought a Dreamcast & learning this natively outputs 480p via VGA I'm debating whether to run this in 480i (the max my BVM can accept) or whether the difference in video quality would warrant acquiring a separate PC CRT for 480p content including the DC & GameCube.

Alternatively would a Framemeister & flatscreen setup prove a more versatile option in terms of performance (input display lag) & picture quality from an upscaler?

Ideally I would like all consoles hooked up to one screen, however I realise due to the varying resolutions between games & hardware a multi-screen setup maybe the preferred choice.

Being recently new to the Retro Gaming scene I would appreciate anyone's opinions & experiences with different setups.

Cheers,
Rob

[BazookaBen]

For 30fps games (Wii/GCN Zeldas, PS2 Final Fantasies, Super Mario Sunshine), 480i is fine, since you get to see the full frame over the course of two scans. For 60fps games (Metroid Prime, Gradius V, F-Zero GX, and Mario Galaxy), 480p will look way better because you only get one scan for each frame. With 480i, 60fps means half the vertical resolution.

I personally use a PVM for 480 line 30fps games and 240p games, and I have a PC CRT for 480 line 60fps games and above. Wipeout HD is a game that truly shines on a PC CRT, thanks to the clear motion you get from the scanning nature of the display.

[Ed Oscuro]

480i/30fps still can look busy due to the interlacing effect, though, especially during the frame transition.

Of course, there's nothing that can be done if that's the only way the game displays.

[Xan]

A Framemeister/flat panel setup is certainly inferior in terms of input lag compared to a CRT, and it can have some issues with region modded systems that you wouldn't notice on a CRT. The main advantage is really screen size and not being confined to 10+ year old displays.

[Flea46]

For 30fps games (Wii/GCN Zeldas, PS2 Final Fantasies, Super Mario Sunshine), 480i is fine, since you get to see the full frame over the course of two scans. For 60fps games (Metroid Prime, Gradius V, F-Zero GX, and Mario Galaxy), 480p will look way better because you only get one scan for each frame. With 480i, 60fps means half the vertical resolution.

I personally use a PVM for 480 line 30fps games and 240p games, and I have a PC CRT for 480 line 60fps games and above. Wipeout HD is a game that truly shines on a PC CRT, thanks to the clear motion you get from the scanning nature of the display.

You make a good point with 60fps content running on a 480i capable screen, I hadn't taken into consideration the issue of vertical screen resolution on my BVM so thanks for that

480i/30fps still can look busy due to the interlacing effect, though, especially during the frame transition.

Of course, there's nothing that can be done if that's the only way the game displays.

That was one of my main concerns, however with the quality of a BVM I wasn't sure if this would be less noticeable compared to a consumer grade CRT display.

A Framemeister/flat panel setup is certainly inferior in terms of input lag compared to a CRT, and it can have some issues with region modded systems that you wouldn't notice on a CRT. The main advantage is really screen size and not being confined to 10+ year old displays.

Thanks for the heads up with with region modded systems, I always aim to stick with NTSC though for the 60Hz speed difference. Living in the UK I grew up with PAL systems & wasn't aware of the difference between 50Hz & 60Hz until later on. Consequently, as far as I'm aware most PC montiors including older CRT's should support a 60Hz refresh rate as standard, so I'm leaning towards picking up a reasonably priced PC CRT.

Having a large screen size is not a deciding factor for me as I'm rather limited by a smaller room this will be setup in. What PC CRT would you guys recommend that is on par with a BVM in terms of colour reproduction & sharpness?

[BazookaBen]

480i/30fps still can look busy due to the interlacing effect, though, especially during the frame transition.

Of course, there's nothing that can be done if that's the only way the game displays.

That was one of my main concerns, however with the quality of a BVM I wasn't sure if this would be less noticeable compared to a consumer grade CRT display.

The thing is, and you'll notice this next time you play a 30fps game, is that all displays have some form of "ghosting" with 30fps, because the image is hitting your retina twice. You can see the effect on this website:

http://www.testufo.com/#test=framerates

The only difference with interlaced displays is that the "ghosted" image is in a sort of comb-pattern instead of solid.

Having a large screen size is not a deciding factor for me as I'm rather limited by a smaller room this will be setup in. What PC CRT would you guys recommend that is on par with a BVM in terms of colour reproduction & sharpness?

Well, PC CRT's are definitely sharper, since they can display very high resolutions, higher than 1080p in a lot of cases. Actually, they're so sharp that at 480p they have scanlines.

As far as color goes, there are many brands that have good picture. You can learn about some of them in this thread: http://hardforum.com/showthread.php?t=952788

From what I understand, the best of the best are the higher-end Sony Trinitron and Mitsubishi Diamondtron tubes, and they can sometimes be sold under other brands such as Dell, NEC, HP, LaCie, and so on. Higher-end Samsung tubes are also pretty good, but according to most people, not quite as good as Sony and Mitsubishi stuff.

But honestly, PC CRT's are becoming so hard to find that if you can spot one in the wild, and you're happy with the picture, you should pick it up. 17 inch is good if you're only playing 480p and 720p stuff, 19 or 21 inch if you're going 1080p and beyond.

[Xan]

It's pretty well known that Sony's GDM series is among the pinnacle of ever produced PC CRTs, although these are getting so ridiculously hard to find that it's almost pointless to look for a specific model. Unless it's literally some budget 1992 monitor that maxes out at a blurry 640x480 you should use whatever you can find and works.

Personally I've never consciously seen neither ghosting (apart from phosphor trails) nor motion combing on 480i games, though I might look out for it the next time. I feel like the listed GC titles aren't good examples of these effects as most of the library there ran with flicker filters, which would probably work well in blurring these effects away. I think if anything the worst offenders might be early PS2 field rendered titles, with the PAL versions being particularily hard on the eyes.

[Ed Oscuro]

The thing is, and you'll notice this next time you play a 30fps game, is that all displays have some form of "ghosting" with 30fps, because the image is hitting your retina twice. You can see the effect on this website:

http://www.testufo.com/#test=framerates

The only difference with interlaced displays is that the "ghosted" image is in a sort of comb-pattern instead of solid.

This is a kind of awkward explanation and the bit about ghosting is wrong. The TestUFO patterns are meant for picking up blur on LCDs at any refresh rate, but specifically at higher framerates (60Hz+), so what you see in your browser has little similarity to a CRT.

It's not hard to visualize what's going on at 30fps at 480i on a CRT: In one sweep of the screen, one set of alternating lines are painted. Even if looking at a perfectly still image, it's possible to see something like "shimmering" as lines immediately next to each other are being painted at different times (and thus at alternating brightness due to phosphor decay); "the image is hitting your retina" only once. This is not ghosting at all.

There's literally no difference between 60fps 480i and 30fps, except that 30fps content is going to have fewer frame transitions so combing effects should often be reduced (but, if you're turning a camera the same amount as in a 60fps game, elements onscreen may have traveled twice as far before the update, making edges show the combing artifact more harshly, but only during the frame transition, not during the 2/60s of a second one full frame is painted).

[BazookaBen]

There's literally no difference between 60fps 480i and 30fps, except that 30fps content is going to have fewer frame transitions so combing effects should often be reduced (but, if you're turning a camera the same amount as in a 60fps game, elements onscreen may have traveled twice as far before the update, making edges show the combing artifact more harshly, but only during the frame transition, not during the 2/60s of a second one full frame is painted).

The difference is that at 30fps 480i, you see 100% of the visual information compared to 480p, with 60fps you only get 50%. So in that sense, they're not that different. I think the combing is not a big deal since you get visual artifacts from 30fps at 480p too, demonstrated in the Test UFO thing. Maybe ghosting is the wrong term.

[Ed Oscuro]

The difference is that at 30fps 480i, you see 100% of the visual information compared to 480p

You mean 480i - but that's still not correct, technically or in terms of the qualities of that information.

The total amount of information displayed onsreen with 30fps or 60fps content running across a 480i60 signal is the same. It is important to keep in mind that the brain doesn't need to process a full frame of information, and two half-frames of information overlaid look more or less like a real one due to persistence of vision. Our prejudices towards "progressive" formats are misleading in another way here at the low end of consumer electronics. What content represents actually determines what is most fitting.

My original point is that 30fps content at 480i60 is not at all equivalent to a progressive display - it doesn't actually fix the issue to our liking. There's still the combing artifacts, especially on moving light/dark edges, but also the annoying shimmer due to the marginal 60Hz refresh rate. The camera is only being updated half as often, so combing effects at 30fps can stand out worse - the time difference between displayed scenes is double that of 60fps, so objects can have moved twice as far. There's still a region of confusion at the edge of 30fps combing artifacts - which should be twice as wide (for a camera panning horizontally) as the combing arfiacts for 60fps, which show up twice as often but are more muted.

Not only this, but 30fps is simply slower than 60fps, no matter the format. You have to wait twice as long for updated information. Quite often people prefer quicker scene updates over more complete but stale information. Our vision allows us to understand visual information even when it's imperfectly presented - like a flickering movie, or interlaced video - but it can't let us respond more quickly if the frame is delayed.

Was this technical design the right choice for 480i? This isn't just something that was considered acceptable only when people wanted faster video games. The original NTSC picture cameras were built before frame buffers were practical, but they still decided that the combing wasn't as bad as the reduced framerate and increased flickering they'd have gotten with a 480p30 design. It is a shame that we can't have true full frames of information, but the extra updates actually can give better understanding through interpolation. The brain is good at this but this is also generally true. Anyway, it's a kind of abstruse math problem.

I think the combing is not a big deal since you get visual artifacts from 30fps at 480p too, demonstrated in the Test UFO thing.

Those aren't combing artifacts and, again, what does a test for fast LCD screens have to do with this?

[BazookaBen]

Ed, try watching the UFO test on some sort of strobing display, either a Lightboost TN panel or a progressive CRT, and you'll see what I'm talking about. 30fps on a 60hz progressive display has a sort of double image thing going on, and it makes it hard to discern detail on stuff in motion. 30fps on a 60hz interlaced display looks very similar, except the double image has that combing pattern going through it. I feel that interlaced combing is only slightly more distracting than the plain double image you get at progressive 60hz. That's why I make the recommendation to just go with whatever monitor has better color for 30fps games.

To be clear, on the "amount of visual information" point, I'm comparing 30fps 480i to 30fps 480p. At 480i, two vertical refreshes gives you one image, at 480p 2 vertical refreshes gives also only give you one image, because the second is the same as the first. That part makes sense, right?

This is just the conclusion I came to after playing Pikmin 2 first on my Dell Trinitron PC CRT, then on my PVM. I enjoyed the game more overall on my PVM.

And you are correct about the shimmer on horizontal lines in 480i, I forgot to mention that.

[Ed Oscuro]

I'm pretty confused about what's at issue here.

I think the initial advice about having a 480i set for 480i content, and a 480p set for 480p content, is good stuff.

The bit about Pikmin is helpful, since it is helping me understand what kind of setup we're talking about. You're playing that at 30fps on the GameCube, right? Naturally, on a PVM you'll just get it output as normal - here as 30fps content on 480i60, as I suspected. And if you had a multisync PVM, 30fps at 480i60 will be displayed as 480i60, not 480p60.

Going to the PC monitor is where things start to get very unclear to me. What framerate and resolution is the monitor actually running when it's displaying the Pikmin 2 gameplay?

As for the "visual information" thing, you've pulled 60fps into that comparison, so I read you as comparing 30fps and 60fps content on 480i60. On 480p60 it is immediately clear that there is no benefit to 30fps for the gamer, due to the doubled framerate, but you can't ignore the temporal aspect for interlaced content either. I'll refrain from writing more since this looks like a story about actual technology implementations rather than just a theory, so I'd need to hear more .

[BazookaBen]

You've noticed that the bottom UFO on moving at 30fps and the top one is moving at 60, right?

On a 60hz strobing display, whether it is a lighboost monitor or a CRT, you will see that 30fps UFO appear as a sort of double image. Hopefully someone else who has a PC CRT or Lightboost monitor can come in and back me up on this.

So I'm not talking about running a lightboost monitor at 30hz, I'm talking about running it at 60, to simulate a 60hz progressive scan CRT. Displaying 30fps material on THAT will show you the effect I'm talking about. Because you're seeing one frame refreshed twice, AKA strobing multiple times per frame, like they're talking about at Blur Busters.

And just to clarify this quote.

The difference is that at 30fps 480i, you see 100% of the visual information compared to 480p, with 60fps you only get 50%.

I'm talking about 60fps 480i at that last part. When you're playing a 60fps game at 480i, you're missing half the vertical resolution you would get from 480p.

[Ed Oscuro]

Sorry, I just edited the post. Still not quite sure I get you; this is quite a journey. First I thought you were saying that 60fps/480i60 looked worse than 30fps/480i60, and now I think you're saying that a game programmed for 30fps/480p60 looked worse than running it at 30fps/480i60. It seems to come down, again, to screen refresh method. In the 60fps/480i60 example I think we identified the constant combing artifacts per 1/60th frame as the culprit, but we have to note that this isn't actually a problem for everyone. Here you're saying that a game (which I believe is going to be outputting the same frame twice) turned out worse at 480p60 than at 30fps/480i60. The difference there is going to be full frame flicker at a high rate, compared with jumbled flicker and shimmering along interlaced scanlines. I don't doubt you are seeing something at 30fps/480p60 but it should be noted that this is not simply strobing a backlight while a screen is held steady - with 480p60 the frame data is being drawn twice, but they're still different frames from the console. I can say this sounds like the "best" method might be to taste, though I'm having a hard time imagining that the method which only masks full-screen effects at the cost of combing effects (even during stable scenes, as I noted) is going to be worse than doing a full screen refresh. I'll have a look but this does seem like being very particular to me.

The Blur Busters / lightboost thing sounds interesting for asking some questions later, but I will say that traditional movie projection uses just this method you took issue with - so when Chief Blur Busters says it's "optimal" to have one strobe per frame and per refresh, this sounds rather more like a technical limitation of the current hardware rather than something inherently better with the cruder splitting of frames in this way. There's problems in that arena based on getting the right amount of illumination.

The difference is that at 30fps 480i, you see 100% of the visual information compared to 480p, with 60fps you only get 50%.

I'm talking about 60fps 480i at that last part. When you're playing a 60fps game at 480i, you're missing half the vertical resolution you would get from 480p.

I think we get it, but it's misleading - that's only half the story, and with many video games it's the less important half of the story.

Yes, 30fps 480i does indeed grunt out an "entire" frame, hypothetically appearing just as you'd get from a progressive source. But 480p is updating full frames at twice the rate.

60fps over 480i60 is trading off mostly redundant vertical lines of resolution so you can get more recent information. Generally speaking I think this is the appropriate tradeoff.

[BONKERS]

480i60 looks fine on a CRT imo.

30FPS is going to have a double image effect no matter what anyway.

[BazookaBen]

Ok, I think we're finally understanding each other.

My point isn't that 480i is superior to 480p for 30fps, just that it's not significantly inferior (as it is at 60fps). So in a situation where you have a 15hz and a 31hz monitor to choose from, and you're playing a 30fps game, you don't necessarily have to go with the 31hz. If the 15hz has better overall color or geometry or something, you can go with that and you won't be leaving any pixels on the table.

But for 60fps, I think progressive scan becomes a lot more important, since you would be missing a lot of pixels, and you should probably use the 31hz capable display.

I guess this discussion only really applies to Dreamcast/PS2/GCN/Xbox games that were 480p capable. And maybe also to people with 1080i WEGA displays and PS4's.

[Ed Oscuro]

After sleeping a little bit, I realized that indeed a double image (30fps on a 60fps set) could easily be more annoying than interlacing effects. Of course, if NTSC was designed for 30 progressive lines per second, that wouldn't be a problem (but instead there would be horrible flicker, so that's not a solution either). Ironically, a "blurry" type of set with persistent pixels (i.e., TFT or OLED) will not show this problem at all, demonstrating again the tradeoffs in place.

My guess is that CRTs and other strobing systems aren't implementing strobes like a movie projector would, so there's apparently still some problem here. I'll still have to ask about that.

[BazookaBen]

My guess is that CRTs and other strobing systems aren't implementing strobes like a movie projector would, so there's apparently still some problem here. I'll still have to ask about that.

On a typical CRT or other 60hz strobing display, you have two strobes for every frame when you're dealing with 30fps material. And you have a 2:3 cadence when watching 24fps material.

Of course, when you're making custom resolutions on a PC, you can have all sorts of configurations. My really weird setup for Titanfall was 129hz interlaced, with the game capped to 43 fps. So I got exactly 3 strobes per frame,when it was running at the cap. If it dropped to 40fps or something, it would be hard to notice because there were so many refreshes per second.

[Ed Oscuro]

Yes, that's obvious, but the point is that movie projectors have multiple strobes per frame and nobody notices a double image, despite having a flicker rate of 72 or even 48fps. (source)

For the PC side, I simply question statements like "the optimal strobe rate" as mentioned at Blur Busters. You were complaining about 30fps on 60Hz, but in your Titanfall example, using that simple math we discussed earlier, there should be a triple image. You haven't indicated whether you liked that setting or not, but it sounds like you did. And the movie projector example linked above shows that the flicker fusion phenomenon can take hold even as low as 48Hz, which is lower than 30fps on 60Hz.

[BazookaBen]

The thing about flicker-fusion threshold is that it all depends on you long the light-source is flicked on, right? If it's an even amount of light/dark time at 48 hz, you will notice flicker, probably. But if the light is on for a little bit longer than it is dark, then you won't notice the flicker.

And yeah, there is a lot of visual noise when I'm playing Titanfall at those settings. But it's a necessary tradeoff when my CPU couldn't maintain a solid 60fps, and my CRT would flicker like crazy if I tried to actually run it at progressive 43hz.

Yes, that's obvious, but the point is that movie projectors have multiple strobes per frame and nobody notices a double image, despite having a flicker rate of 72 or even 48fps. (source)

I think the reason you don't notice the double image is that there is natural motion blur in film that masks the effect. In Fantastic Mr. Fox, a stop-animation movie from a few years back, I notice double images like all the time in fast moving scenes. Actually made the movie a little hard to watch a couple times, because I wasn't used to seeing that in a theater.

So yeah, I think that's why you see motion blur used all the time in 30fps games on consoles, it does a decent job of hiding this effect, as well as just making frame transitions looks smoother overall.

[Ed Oscuro]

Yeah, Wikipedia isn't very clear about how long the light/dark pulses act, and of course with a traditional movie projector, it's not as simple as strobing a light source, due to the mechanical rotating shutter there's some math involved to figure out the actual result.

What you're saying about the motion blur does make sense, and I trust you on the Mr. Fox flicker too.

Interesting discussion, kind of reinforces that the "best" display tech will have to be flexible to support different uses. Constant-on displays seem like they'd be best for some content (at least for some users), but they need strobing too for reducing motion blur at higher framerates. That said, screw game companies that push out 30fps games

[BazookaBen]

I think the scanning method Sony is developing for OLED is pretty cool:

https://youtu.be/jTfvwOGu4EI

I imagine that would look really good in practice but I couldn't afford a monitor to see for myself.

And I think 30fps is fine for some games, especially slower paced ones. All the 3D Zeldas on console have been 30fps (or lower), and it's worked out ok.

[Xan]

Ironically enough the uploader of that video thinks it's not so cool?

[BazookaBen]

Haha, didn't notice that. It's probably a 60hz monitor, and he's probably doing photo work, so I could see how the flicker would wear on him. All they would really need to do is make the scanning area thicker.

[Xan]

Slightly related to this I suppose...

I was checking out this 480p footage of Metroid Prime and noticed how pixelated that scan zoom effect looks. It's been years since I played this last time, and that was in 480i composite, but I don't remember this effect sticking out that much... either it's due to the upscaling or the interlacing really somehow masked it a bit?

[BazookaBen]

Metroid Prime just has a lot of aliasing like any 640x480 game. That footage isn't great either, it's running at less than 30fps somehow, when the original game is 60fps.

[Josh128]

I played Prime at 480p from day 1 in 2002 on my Hitachi Ultravision. It is very crisp and does exhibit aliasing on edges, and the scan zoom effect is kind of like a non-interpolated zoom, so yes it does pixelate a bit. On the whole, Prime 480p looks incredible to me, far better and sharper than 480i IMHO. In any case Ben is right, that video is definitely bad footage to gauge it by. That looks like blurry garbage on the PC CRT Im currently viewing it on.

You have an F4500 right? Put it in 4:3 mode and run progressive scan at a sharpness of 40 to 50 and it looks essentially identical (probably at least 95% ) to how it does on an HDTV 480p CRT set.

[Xan]

Are you running this in Flash? You need to be running it in Firefox (or maybe Chrome too) with HTML5 and it works in 60 FPS. This is a pretty new feature on Youtube since last year or so. I think the footage this guy uploads is pretty good by Youtube standards, not sure what you guys are going by...

Agree about the aliasing, but I think this is probably from the lack of deflicker which tends to work as makeshift anti-aliasing on 480i. I think it looked smoother there, although I can see how 480p looks crisper and has more motion detail.

@Josh, Nintendo denied PAL users the option of 480p. The hardware is capable of it but the option was taken out from all the games.

[Josh128]

@Josh, Nintendo denied PAL users the option of 480p. The hardware is capable of it but the option was taken out from all the games.

Nintendo is so strange-- they actually gave that system pretty advanced hardware for the time, then proceeded to make it so difficult for most users to exploit its full capabilities via the denial of PAL users 480p and making the component cables almost inaccessible for all but the most jaded videophiles even in NTSC land, that probably less than 5% of GC owners worldwide actually got to experience it.

[Xan]

Yea, not sure what they achieved by telling the developers to do that. It was pretty irrelevant back when the GC was current as no displays were available to use it, practically no 4:3 CRT had component and same even for most flatscreens until HDTVs became mainstream, but would be a useful option today...