Bigger screen, same resolution = how's text legibility?

[Core]

This question is so fundamental and basic that I am almost embarrassed to post it, but somehow I just can't wrap my head around it.

My grandfather has a 19" monitor that he uses with Windows 7 to mostly browse news sites, read PDFs, and that sort of thing. He uses the built-in zoom function because most of the time the text isn't quite large enough for him to comfortably read.

I got a new laptop and won't be using my PC with a dual-monitor setup anymore, so I am thinking about giving him my second monitor, a 24" TN panel. His 19" just looks so horribly small and uncomfortable. What I am wondering is, will the larger screen with the same resolution make text more, or less legible? Or precisely the same?

I prefer my font sizes very small, and have, surprisingly enough, never had to consider this before. I've always gone for the highest resolution no matter how tiny the text - the more stuff on the screen the better! But his needs differ.

He's in the hospital and I was thinking about putting the new monitor in as a surprise for him to come home to, but I don't want to do it if it makes it harder for him to read stuff online, because he really loves it.

 

[Ian]

That's a very nice thing for you to do

It depends, as if you're trying to force a monitor to a non-native (lower) resolution it has to stretch it across the screen and scale it as best it can. Depending on what the resolution is and the pixel count, then it could be about the same - but it's probably not going to be ideal. If the aspect ratio is different, then that's going to be another reduction in quality if the resolution is maintained and it's forced to stretch.

Is there a reason that you can't up the resolution to the recommended? You can always increase the text size through the OS, or use zoom in the browser?

edit: Actually, why don't you find out the resolution he uses and then just lower it on your PC to test it out

 

[Core]

Actually, he appears to use 1920x1080, and he uses the Magnifier or the browser's zoom to make the text bigger.

 

[Ian]

Sorry Core, I may have got my wires crossed - are the monitors max resolution the same?... I misunderstood and thought you meant they had to be set to the same resolution, with a different max because of the large size difference. What I said above will make no sense in that case!

If they're the same max res and the monitor is larger, then he should find it more legible and easier to read.