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Old 17 July 2017, 19:00   #21
idrougge
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Exactly. A TV will more likely show the correct aspect ratio since they don't have accessible height controls.
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Old 17 July 2017, 20:06   #22
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Or a broadcast monitor, those should be the perfect measure.
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Old 17 July 2017, 20:30   #23
idrougge
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At least as long as it hasn't been used by gamers.
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Old 17 July 2017, 21:08   #24
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I mentioned what I think would be "correct" aspect ratios in this post.

For NTSC, the Amiga Hardware Reference Manual implies (or at least alludes to) the same NTSC pixel aspect ratio as mentioned there, 6:7. And a 4:3 visible region (centred on the default Intuition screen position) of 336◊216 low-res pixels. Which is a nice round 8 pixels on each edge past the non-overscan 320◊200 region.

For PAL, pixel aspect ratio of 26:25 is good enough, and at least in emulation my pixel aspect ratio OCD isn't bad enough to bother with trying to achieve that. [In other words, I just use 1:1 in emulation.]

Of course back in the day, probably like most people with a 1084 monitor I just adjusted image size to make it as large as possible with the default 640◊256 PAL Workbench still completely visible.
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Old 18 July 2017, 09:12   #25
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Quote:
Originally Posted by mark_k View Post
Of course back in the day, probably like most people with a 1084 monitor I just adjusted image size to make it as large as possible with the default 640◊256 PAL Workbench still completely visible.
I always ran my WB at max overscan with the monitor adjusted to show all of that. :-)

In 1.3 I used Johnathan Potter's PPrefs to adjust the overscan. http://amiga-fish.erkan.se/amiga-fis...ontent-PPrefs/
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Old 18 July 2017, 16:23   #26
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Did you guys not stretch the image up on certain games to attain full screen? I did. I unfortunately touched those controls more than I ever should :P
I can't remember exactly which game it was, but there was one where I stretched the vert so much the scanlines got reaaaally wide
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Old 18 July 2017, 18:07   #27
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Did you guys not stretch the image up on certain games to attain full screen? I did.
Yeah I did too, you had to with certain games.
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Old 18 July 2017, 23:20   #28
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Couldn't do that with your basic 14" Colour TV without opening it up and poking around inside, and I didn't know anyone with a monitor attached to their Amigas.
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Old 19 July 2017, 07:23   #29
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Did you guys not stretch the image up on certain games to attain full screen? I did. I unfortunately touched those controls more than I ever should :P
I can't remember exactly which game it was, but there was one where I stretched the vert so much the scanlines got reaaaally wide
I never touched them after the initial adjust. I found it really annoying to fiddle with the controls all the time.
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Old 19 July 2017, 09:50   #30
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Yes I forgot about the v and h controls.
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Old 19 July 2017, 15:56   #31
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I never touched them after the initial adjust. I found it really annoying to fiddle with the controls all the time.
It WAS annoying, but that extra screen space!
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Old 19 July 2017, 22:21   #32
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I didn't know back then that NTSC games were supposed to fill the screen. I guess I thought their screens were smaller or something

What's weird though is there are games that leave the PAL sized area unused that don't actually work on NTSC Amigas.
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Old 19 July 2017, 23:32   #33
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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?
Phew! You inspired me to write up a complete answer to all you need, in order to create and truly enjoy perfect aspect ratio graphics on Amiga!

It has a picture that I hope can be considered the truth at least.

And maybe there is one or two interesting details all of you Amigans in here don't already know.
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Old 20 July 2017, 00:25   #34
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Photon, what do you mean about 16 scanline skips?
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Old 20 July 2017, 00:52   #35
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And maybe there is one or two interesting details all of you Amigans in here don't already know.
Nice one!
One problem with the method though.
Not all versions of Deluxe Paint will draw a perfect square. Usually the tool will draw a Xpx by Xpx image, but if your screen is squished because it's NTSC, when it gets stretched, they will look tall.

I realized this while testing this same issue for a very troll-friendly thread here : http://eab.abime.net/showthread.php?t=82793
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Old 20 July 2017, 00:54   #36
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Photon, what do you mean about 16 scanline skips?
In 2011, the scaler chips in LCD TVs mentioned became decent and standardized. Before that, results varied. You could get a blurry picture even on RGB Scart, you could get a sharp picture with doubled lines, or if the LCD resolution was lower than 800x600 (such as on smaller 4:3 TVs), you could get a sharp picture, but it would squash 320x256 to 4:3 and skip 16 scanlines - every nth line. It was just a bunch of different chips that did things differently.

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Nice one!
One problem with the method though.
Not all versions of Deluxe Paint will draw a perfect square. Usually the tool will draw a Xpx by Xpx image, but if your screen is squished because it's NTSC, when it gets stretched, they will look tall.

I realized this while testing this same issue for a very troll-friendly thread here : http://eab.abime.net/showthread.php?t=82793
That chapter is for setting up 1:1 pixel aspect ratio on CRT displays. The article says to use the Grid or Coords tool to ensure that it's really square - in pixels - before whipping out the ruler.

I do go through graphics drawn on NTSC displays, and certainly all graphics drawn for PAL or square pixels will look stretched on NTSC - graphics drawn for square pixels slightly less so. Whether to draw specifically for NTSC CRT displays today is really up to the artist, but as I mention in the summary Amiga users will find a way

It's all a matter of practicality, and today it just has to be square pixels I think. I've had to abandon my fierce conviction that they should be PAL pixels on CRT only; I simply don't have as many arguments against square pixels as I have for PAL-squashed pillow-shaped ones.

Last edited by Photon; 20 July 2017 at 01:11.
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Old 20 July 2017, 00:58   #37
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I think that varies a lot more than that. All my LCDs will render my Amiga screen without scanline skipping. Do you mean yours would skip 16 rows in one go or distributed across the picture area?
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Old 20 July 2017, 01:03   #38
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That chapter is for setting up 1:1 pixel aspect ratio on CRT displays. The article says to use the Grid or Coords tool to ensure that it's really square - in pixels - before whipping out the ruler.
The problem is the pixels themselves, the aspect ratio changes when you change screenmodes, but most software is still doing what, as I said, is the same amount of pixels on X and Y. But if the pixels are shorter on Y...

I'm not sure which version of DP had this problem,. I'll just have to illustrate to you with an example so you don't think I am a crazy person I think this got fixed from DPIII on. Basically if you are in true NTSC mode, a square will not have X and Y being equal.

Do this quick test though: Grab your Deluxe Paint version, draw a 20x20 square, change screenmode to NTSC, and it should be squashed.
Now if your version of Deluxe Paint is the correct one, if you make a square in NTSC, it should look fine compared to the other one. If it looks the same, it's buggy.
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Old 20 July 2017, 01:27   #39
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I think that varies a lot more than that. All my LCDs will render my Amiga screen without scanline skipping. Do you mean yours would skip 16 rows in one go or distributed across the picture area?
Every nth line. (=distributed) And yes, I can't hope to cover all the variations.

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The problem is the pixels themselves, the aspect ratio changes when you change screenmodes, but most software is still doing what, as I said, is the same amount of pixels on X and Y. But if the pixels are shorter on Y...

I'm not sure which version of DP had this problem,. I'll just have to illustrate to you with an example so you don't think I am a crazy person I think this got fixed from DPIII on. Basically if you are in true NTSC mode, a square will not have X and Y being equal.

Do this quick test though: Grab your Deluxe Paint version, draw a 20x20 square, change screenmode to NTSC, and it should be squashed.
Now if your version of Deluxe Paint is the correct one, if you make a square in NTSC, it should look fine compared to the other one. If it looks the same, it's buggy.
I definitely want to know if you find any omissions or errors!

The article is meant as a final word on display and aspect ratio, with the specific goal of letting users set up their display and know what they're doing.

But you are probably talking about an option in the Prefs menu. I specifically did not mention it, to avoid this kind of confusion

And to do it correctly (not make the topic more complex than it is), you must eliminate variables, and there are too many variables in your example. I simply don't know what happened on your monitor in one version of DPaint when you went from one screenmode to the other. But it was probably the option. Or performing the wrong test, perhaps?
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Old 20 July 2017, 07:19   #40
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I'll explain by demonstrating, because I don't seem to be explaining myself properly.
No, it isn't an option.
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