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The HTPC in my living room is the fastest/most modern PC I own. My current TV is a 24" tube TV, so I have to hook up a secondary monitor in order to read anything besides the menus in Windows Media Center, and that alone is kind of annoying. I'm also tired of having to sit on the floor to do any web browsing or reading on the PC, since there's no practical way to set up a computer desk over there.

I've seen charts on recommended TV sizes for various viewing distances, but those are all oriented toward home theater, not the ability to read web pages from a distance with little or no eye strain. I'm curious whether anyone has personally tried web browsing or coding on a 1080p TV from halfway across the room. If so, what size TV do you use, and how far away do you sit (from the screen to your eyeball)?

More specifically, is a 40" 1080p LCD HDTV adequate for web browsing, reading, and general-purpose computing while sitting 12-15 feet away? If not, do I need something bigger/need to move a little closer? What size and viewing distance should I be shooting for? Aside from resolution (I'm already settled on 1080p), are there any other factors that will make a noticeable difference in the TV's performance as a computer monitor?

I found a similar question, but it wasn't quite specific enough to answer my question: How functional/practical is it to use an hdtv as a computer monitor?

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rob
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  • Thanks for the help, everyone! FYI, in the end I decided to go with a 32" 1080p LCD TV for a computer screen/regular TV viewing (at a shorter distance), and a separate Epson PowerLite Home Cinema 720 projector for movies. The total cost was about the same price as a decent-quality 50" TV, which is what I would have needed from my originally-planned viewing distance. – rob Jan 18 '10 at 03:35
  • It turns out the 32" LCD TV only works well as a computer monitor from about 4 feet away. I usually have to zoom the text quite a bit to make it readable without squinting, but it's great for playing games at about 5 feet. Another drawback to using the TV as a monitor is that it doesn't seem to have a low-power mode when the signal is disconnected (e.g., when the computer goes to sleep). Instead of going into standby, the TV displays a "no signal" message. – rob Feb 02 '10 at 21:02

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If you're viewing 1080p (1080x1920) resolution on a 40'' TV, you should be fine. Especially when it's an LCD. Again, if it's too small, just bring down the resolution on the same ratio, it should make things a lot more viewable. I know that if you hook up a PC sometimes to a large display like that, you'll definitely get a lot higher native resolution, but to able to view that higher resolution, you have to be like 5 feet away from the screen in order to read the text.

Steven Lu
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  • I'm aiming to use the native 1920x1080 resolution because I don't think 720p would cut it for general-purpose computing and web browsing. But thanks for the pointer on minimum viewing distance. I hadn't really given that much though, since the primary goal is to use the screen as a computer monitor from across the room. – rob Jan 09 '10 at 21:43
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It would depend on your vision, but for me, 12 feet is way too far. I'm sitting about 2 feet from a "1080p" (OK, 1920x1200) 24-inch screen right now. Looks about right. So if the screen and pixels were twice as big, I could be twice as far back: 4 feet. To test it the other way, I also stood about 6 feet from this screen, and it was not comfortable reading at all.

That might even be a handy rule of thumb: for a 16:9-ish 1080p-ish screen, the viewing distance (for computer text like on a web page) is the same as the diagonal.

If you can't sit that close, some modern web browsers do a decent job zooming pages, and many programmers' editors allow you to choose the text size for the main editor (less so for the other on-screen tools). It seems counter-productive to reduce the desktop size to make the pixels larger: in this scenario, to double the viewing distance from 4 feet to 8 feet, you'd have to shrink the desktop from 1920x1080 to 960x540. Some dialog boxes get chopped off at 540.

You also want a TV that does (at least have the option for) "1:1 pixel mapping": i.e. each pixel generated by the video card -- connected digitally through DVI or HDMI or DisplayPort of course -- to be exactly one pixel on-screen. TVs are generally designed to crop off say 5% around the edges, called overscan, and zoom the picture slightly to fill the screen. That's because the edges are sometimes blank or have garbage pixels. Computers do not have this problem. Aside from the "slightly smudgy" pixels that result, the edges of a computer desktop often have critical things like taskbars and menus. To work around this, you can sometimes force the video card to shrink the desktop so that it fits inside the overscan, but that makes it even smaller.

Ken
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  • Thanks for the firsthand info. I knew about overscan, but I thought it was only used for tube TVs or analog inputs. Are you sure it's also used for HDMI? I checked the spec sheets on some Samsung TVs just now and didn't see 1:1 pixel mapping listed. Thanks again. – rob Jan 09 '10 at 20:02
  • Unfortunately, but not surprisingly, the feature has different names. I have seen garbage pixels on the edges of OTA ATSC, so it's not just for analog. – Ken Jan 10 '10 at 15:10
  • I think I've read elsewhere that the "garbage" pixels across the top of the screen are actually encoded information. Nonetheless, I'm marking yours best answer because of your personal observations on various screen sizes/viewing distances. – rob Jan 18 '10 at 03:29
  • Just posting another update; I did notice that there was a "Native" setting for my TV which does the 1:1 pixel mapping. – rob Feb 02 '10 at 20:58
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Someone posted me this link which has a graph of screen size, resolution and optimal viewing distance.

I haven't investigated it in great detail, but it looks like it might contain some useful information for you.

ChrisF
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  • Thanks; that looks like a good reference to figure out the viewing distances at which the level of detail drops off. Based on the charts, I might have to pull the couch up so it's only 5-7 feet away (about half the distance I was planning), in order to distinguish full 1080p detail on a 40-50" screen. – rob Jan 09 '10 at 21:38