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Old 24 June 2017, 03:38   #1
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The real aspect ratio?

So Iím playing around with resolutions and filters on WinUAE and I was wondering what is the original aspect ratio (that being the one used back in the day.) I have narrowed down my options to three using Automatic scaling and scale2x.

The first is to use a 4:3 aspect ratio resolution and stretch the image for the resolution. The second is to use a 4:3 resolution and keep the games image aspect ratio using the option ďkeep autoscale aspectĒ. In this way the internal aspect ratio of the programming is kept in and shrunk down to fit in a 4:3 screen. The third option is to use a 16:9 resolution and use ďkeep autoscale aspectĒ to make the image bigger (and take up more of the screen) while keeping the internal aspect ratio which I geuss it not much different from the second option. I could also just starched the image to a 16:9 screen but I donít think these games were meant to be played like that.

The question is how did most people back in the day view their games. My understanding is that widescreen monitors didnít exist back then (or were really rare). So how was it done did Amiga user have special Amiga monitors that were sized just for that family of computers? If not then it must have been a 4:3 and if so was the image starched to 4:3 or was it shrunk down to fit while still maintaining the internal resolution of the game?
 
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Old 24 June 2017, 22:06   #2
Toni Wilen
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4:3 was the only aspect ratio. But note that TV pixel ratio was not exactly 1:1.
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Old 25 June 2017, 00:21   #3
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So if 4:3 is all they had was the image starched to 4:3 or shrunk down to fit in 4:3 while still maintaining its original ratio (with black bars)?

As for TV pixel ratio not exactly being 1:1 I donít think that matters much you could say that for any emulated device from the Atari 2600 to the Playstation. What matters is where the games meant to have black bars or be starched to fill the whole 4:3 screen.
 
Old 25 June 2017, 00:28   #4
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The Amiga screen size is programmable. So, a lot of games have black bars. Some bigger, some smaller. And a few are in PAL overscan which fills the whole screen (like The Settlers or some Team 17 games).
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Old 25 June 2017, 01:58   #5
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But after the programming was done what did the monitor itself do with the image starch or shrink down?

See with other system that connect to tvs like the SNES it was always meant to be starched to 4:3 (maybe with some tv overscanning but thats another thing altogether) even though it had aspect ratio 8:7.this is different from systems like the GBA that had its own screen specifically sized for its games at 3:2. So for GBA its batter to set the resolution to 16:9 and fit the image to scale as big as it can go within that 16:9 Resolution while still maintaining its ratio. If you starched the image either to either 4:3 or even 16:9 youíre distorting the image from what it was original intended to look like.

So regardless of what the programmer does with the image after its sent to the monitor was it meant to be starched or shrunk down to fit.
 
Old 25 June 2017, 02:44   #6
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The image was always stretched to 4:3, not matter what viewable screensize was programmed. With all the black bars intact (or not if in PAL overscan).

A lot of games are in 320x200 or pretty close to that resolution (which doesn't automatically means they were in NTSC). So, on NTSC screens it fills most of the screen while on PAL screens the image has bigger black bars. Well, monitors had of course knobs which that you could manually tweak the horizontal+vertical size to minimize the bars, TVs not.

Last edited by Retro-Nerd; 25 June 2017 at 03:01.
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Old 25 June 2017, 03:25   #7
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If itís starched to 4:3 there should be no black bars. When I say black bars Iím not talking about internal black bars in the program itself Iím talking about black bars on the monitor that result from the image not taking up the whole screen because it was shrunk down to fit. If the internal program has black bars and the image is not starched to 4:3 thatís double black bars but I donít care about that since internal black bars are meant to be a part of the game regardless. Letís assume the game image is a solid color all white every pixel. If you starch it to 4:3 then that 4:3 monitor should be all white as well. But if donít stretch the image it must be shrunk down to fit meaning there will be black boarders from the area the image wonít fit into because of ratio mismatch.
 
Old 25 June 2017, 05:28   #8
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I used my LG Widescreen monitor with my real A500, and I regret using it. Now I am using a 1084S monitor and I am happy with it.
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Old 26 June 2017, 10:17   #9
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It is normal to have border regions in every edge of screen and different programs can use different screen sizes. There is no "standard".

And as was replied previously, there are many "PAL" Amiga games that only use NTSC height and by design have big black bar at the bottom. (and run in wrong speed in NTSC mode)

Only exception is few full overscan programs (for example The Settlers) that fill the whole screen but they also can have slightly different horizontal positioning.

-> You can't have single perfect monitor (or emulator) size/position adjustment. Amiga is different (too flexible ) compared to most other computers or PC VGA etc.. (8-bit Ataris is one exception but it also does not have as flexible screen width configuration)
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Old 04 July 2017, 14:47   #10
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I wonder if it would be worth making a web page where this concept is explained in no uncertain terms. Perhaps even with a screenshot of a 1084 adjusted Properly (tm) so that the max overscan is visible, then various different games being started without touching the knobs. Gasp! The games don't fill the screen! Also, most will show up on the right edge of your properly adjusted monitor, some show up more centered.

Then perhaps the exact same settings/games on the Amiga end but with some old Scart TV to outline how they looked.

Perhaps go even further and show the same software with an Amiga that is forced into 60Hz NTSC mode. :-)

One of these days I'll see this discussion once again and be pressured into action. ;-)
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Old 04 July 2017, 23:26   #11
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I remember playing settlers through rf on an old 14 inch goldfish bowl tv.
The geologist's indicator in the bottom corner of the screen was barely visible - my first experience of overscan.
On amiga, games filling the screen was so rare you can name check them today.
When you play megadrive games via emulation today the opposite is true, they all have tonnes of overscan. I guess that's blast processing for you.
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Old 04 July 2017, 23:32   #12
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Quote:
Originally Posted by rare_j View Post
On amiga, games filling the screen was so rare you can name check them today.
When you play megadrive games via emulation today the opposite is true, they all have tonnes of overscan. I guess that's blast processing for you.
I guess that's emulation for you.
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Old 04 July 2017, 23:52   #13
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Ha ha, you know what I mean. On a tv megadrive games went edge to edge. The extent of the overscan is only fully visible via emulation.
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Old 04 July 2017, 23:57   #14
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I was just trying this stuff myself.

One thing that does bother me is how the aspect ratio on NTSC is particular broken on PAL machines. For example, NTSC interlaced (640x400) when stretched to the correct 4:3 aspect ratio isn't anywhere near as squashed looking as PAL interlaced.

The main way I've been getting around it is to use a 4:3 window resolution, such as 1600x1200 and then the default scaling seems to be more or less right without having to use any other settings.

I've had some problems with screen scrolling though when I use scaling. Sometimes the screen stretches vertically, sometimes it just breaks.
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Old 05 July 2017, 01:52   #15
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Ha ha, you know what I mean. On a tv megadrive games went edge to edge. The extent of the overscan is only fully visible via emulation.
Megadrive games were always letterboxed on PAL tvs.
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Old 05 July 2017, 02:15   #16
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Yes you're quite right. But not on 60hz sets.
I don't really know where I'm going with this thread hijack so I'll stop here.
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Old 05 July 2017, 08:13   #17
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Quote:
Originally Posted by teppic View Post
One thing that does bother me is how the aspect ratio on NTSC is particular broken on PAL machines. For example, NTSC interlaced (640x400) when stretched to the correct 4:3 aspect ratio isn't anywhere near as squashed looking as PAL interlaced.
Apparently Jim Sachs was mortified by this fact, his art was meant to be viewed on an NTSC machine in 4:3.

Us OCS guys in the late 80s didn't know any better, we'd never seen an NTSC machine so we saw the squashed 256 line versions of all those old pictures. :-)
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Old 17 July 2017, 02:20   #18
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How the Workbench looks on original Amiga with 1084 monitor is a good example. You can the typical image here:
[ Show youtube player ]

Here is another example:
[ Show youtube player ]
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Old 17 July 2017, 02:57   #19
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On my old CRT TV, 320x256 filled the screen (not taking overscan into account), but 320x200 had a single black bar at the bottom of the screen. Pixel size/aspect ratio remained the same regardless of screen height for those two resolutions.

Made NTSC games look a bit shit, tbh
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Old 17 July 2017, 18:00   #20
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Quote:
Originally Posted by rsn8887 View Post
How the Workbench looks on original Amiga with 1084 monitor is a good example.
Unless you have, like me, a 1084-D1, which at least on the EU version, will squash the NTSC image automatically to kinda make it look like the PAL image.
My old "square box" 1084 didn't do that.
Of course all is good with PAL.

But then again., you forget, everyone messed with their monitors'V and H size controls.
So all these videos actually show nothing to be determined as "truth"
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