# What times 1024 = 1.33333? (aspect ratio question) [Solved: It's 1350-ish]

Registered User regular
edited August 2008
Ok, I have two brand new monitors and I have run into an interesting aspect ratio problem.To better understand my plight, I have to explain how I have the monitors set up.

My primary display on the left is an 18 inch 4:3 Samsung running at 1600x1200 (max resolution)

My secondary display on the right is a 16 inch 4:3 HP running at 1280x1024 (I'll get to this is a second)

Now, the monitors sit side by side, but the right one is on a platform making it slightly higher than the left. It looks like this, and the display properties set up like the screenshot below.

Now my dilemma...

I spent about a half hour last night color balancing the two monitors. The left one was slightly warm, giving my windows a very light red hue. The monitor on the right gave off a slight blue one. Both monitors have color balancing options so I synced them using a myriad of color bars and now I'm happy that whatever color shows up on one is repeated on the other. There are some brightness/contrast issues, but because the monitors are different makes, I'm not too concerned with luminosity. It's just nice to have a window across both displays that glow the same color white.

After I was done color balancing I decided to sync up the resolutions. What is cool is at my current settings, the vertical resolutions match exactly. The right monitor, being two inches smaller, is running at a lower resolution. It turns out that going from 1200 to 1024 is a difference of ~2 inches of physical screen size. This means that my windows, when dragged from one display to another is not "blown up" or "magnified" when moved to the other, smaller display.

The issue I have, however, is that my horizontal resolution is a little wacky. My display properties window, for example, measures 3.5in x 4in on the big display, but 4in x4in on the smaller one. Doing some math I found out my aspect ratio is screwy on my smaller display. I'll do the math real quick for you to show you.

Control set = 1024x768 = 4:3 = 1.333333 aspect ratio with perfectly square pixels.

Primary display = 1600x1200 = 4:3 = 1.333333 aspect ratio with perfectly square pixels.
Secondary display = 1280x1024 = 5:4 = 1.25 aspect ratio, with pixels longer than they are high (!)

So I'm trying to find an aspect ratio that will match across displays. So I need a resolution that is nnnn x 1024 = 4:3 = 1.33333 aspect ratio. I don't know what nnnn is supposed to be I'll be damned if I can find the right number to give me 1.333333. The math doesn't work with any of the resolutions given to me by my graphics card. I'll probably just use one of those programs to tweak the display into a nonstandard resolution.

Now, before you guys thing I'm being kind of OCD about this, I am. I also play with 3D modeling a lot and I can notice when a prefect sphere on the one display gets flattened on the other.l It's bugging the heck out of me.

Some someone solve for nnnn?

halkun on

## Posts

• Registered User regular
edited August 2008
EDIT: nevermind

TM2 Rampage on
• Registered User regular
edited August 2008
Aha! You see! You see my dilemma now? (^_^). I thought it was going to be easy too.

halkun on
• Registered User regular
edited August 2008
Sounds like your primary issue is just that your graphics card won't offer the proper resolution (actually, I think most cards poll the monitor to figure out what resolutions it supports as well).

Anyway, obviously what you want is approximately 1365 pixels (doing the simple math).

On my monitor/card combo, I am offered 1360x1024 (not an entirely "standard" res, but not uncommon either), which would probably be close enough for you. But yeah, if your not being offered that resolution you'll have to find a way to force it.

mcdermott on
• Registered User regular
edited August 2008
Yeah you need about 1365 x 1024.

SirToasty on
• Registered User regular
edited August 2008
Two things:

First, the monitor with 1280x1024 native resolution will not truly support any resolution with horizontal component greater than 1280, so the suggestion of ~1365x1024 is not really meaningful. (Note: if this monitor is a CRT then you can probably ignore this.)

Second, and somewhat related to the first, the native resolution of a monitor -- assuming it is an LCD -- is the resolution that it displays properly. Any other resolution will have to be upscaled/downscaled to this resolution by the display, so if you were to switch it to, say, 1280x960, you would see some distortion if you used the entirety of the screen.

I'm sad to say there isn't really a "good" fix to your problem. You can possibly force a 4:3 resolution on your monitor by using letterboxing if your video card or monitor supports it; but this will still have the pixels-per-inch problem you noticed because the pixels on an LCD are immutable. Consequently this solution would just remove part of the working space on your monitor to no advantage. The other possibility (and I'm not sure how this would be implemented) is to run 1365x1024 and allow your monitor (assuming it is capable) to downscale the horizontal component to 1280. This would provide correct horizontal pixels-per-inch, but unfortunately would lead to significant degradation in image quality on the monitor due to the downscaling.

Clipse on
• Registered User regular
edited August 2008
Yeah, for whatever reason I just assumed he was talking about CRTs. Because if you're on an LCD, you pretty much just want to always run it at native resolution, period.
The other possibility (and I'm not sure how this would be implemented) is to run 1365x1024 and allow your monitor (assuming it is capable) to downscale the horizontal component to 1280. This would provide correct horizontal pixels-per-inch, but unfortunately would lead to significant degradation in image quality on the monitor due to the downscaling.

Translation: this will look like utter dogshit, and will probably bother any OCD tendancies you have even more than the aspect ratio issue.

mcdermott on
• Registered User regular
edited August 2008
Both displays are CRT monitors.

The magic number is 1350x1024. 1365 whacks out the card's clock cycle.

Thanks guys! It's now at an aspect ratio of 1.318 (1.32 rounded) , not 1.33, but I'll take the rounding error and being a hundredth off won't kill me. I can manually correct further by making with the stretchy-squeeze using the manual monitor knobs.

Side note: My contrast/brightness seems a little more in sync with the other monitor as well. The scanline frequencies are now the same on both displays. Bonus!

halkun on
• Registered User regular
edited August 2008
Excellent! Good to hear!

It's also good to hear that I'm not the last person on the planet with dual CRTs on his desk...though both of mine are the same model, and both were free! :P

mcdermott on
• Registered User regular
edited August 2008
Mine were free too. I kind of prefer CRTs in this case because you can feed them analog resolutions, and if the graphics card doesn't freak out, use them with no artifacts.

I just thinks it's cool to be able to drag a window between two different monitors at two different resolutions and maintain aspect ratio. As a side note 1280x1024 is a known whack resolution. It was designed because in the 80s you needed exactly 1.5MB of video memory to display it and ram chips were expensive back then. There is only one other 5:3 resolution that is "standard"

Also, 17" CRT monitors are most often physically 5:3, but mine is smaller. The max of the smaller one is 1600x1200 as well, but it's blurry as hell and it whacks out the coveted 1024 vertical resolution I was looking for.

EDIT:

Here is a screenshot showing how the aspect ratios match now.

halkun on
• Registered User regular
edited August 2008
I'm not quite anal enough to have measured the aspect ratio on mine, but they're both 19" CRTs, and both do 1600x1200 beautifully (75 Hz, and sharp). Plus of course they have those nice more-or-less flat tubes.

I got them when my CS department upgraded a few labs to LCDs, and gave all their old CRTs away. Pretty sweet. Though of course after next year when I start making actual money I'll probably replace them, if only to save on electricity.

That's actually pretty cool that you got the resolutions and sizes to work out that nicely. Also an interesting tidbit on the 1280x1024 resolution. I guess I never knew about that, because back when video RAM was horridly expensive I never had a monitor capable of it anyway (I think my best monitor then could only do 1024x768).

mcdermott on
• Registered User regular
edited August 2008
Weird, 1360x1024 is a supported resolution on my system (and is pretty close to the 1365 1/3 you get by dividing 1024 by three then multiplying it by four), and I used to use it until I decided that 1600x1200 wasn't too small after all. I hate that 1280x1024 is the only common resolution that's 5x4.

Transparent on
PAXtrain '10, let's do this!
• Registered User regular
edited August 2008
Oh, it is 1360x1024. I made a type-o

halkun on