Printer and Screen Resolution

A recurring theme in Edward Tufte's books is the massive difference in resolution between the printed page and computer displays. Printed pages lend themselves to vastly greater information density.


This is a companion discussion topic for the original blog entry at: http://www.codinghorror.com/blog/2006/12/printer-and-screen-resolution.html

OTOH, I can zoom in on screen…

There are zoom tools for printed materials too.

even with fabulous 2400 dpi output, offset-printing color reproduction uses screens

Here are some color sparklines from Beautiful Evidence scanned in at 1200 DPI.

There is a bit of dithering, but less than I expected.

Could printed resolution being higher than display resolution explain why I understand things I read in a book a lot better than things I read on wikipedia?[1]

[1] Dyson, Mary, and Haselgrove, Mark. “The effects of reading speed and reading patterns on the understanding of text read from the Screen.” Journal of Research in Reading 23.2 (2000): 210-23

Definitely there’s a point when even the best designed interface can hit information density overload if you keep cramming more smaller items in. But that’s exactly why a lot of comfotable-to-use systems will allow you to scale the font (or full page in the case of opera) sizes, which usually pushes elements away from each other, until people find their optimum mental breathing room.

Interesting stuff about ClearType…

http://www.grc.com/cleartype.htm

Another thing, the blurry ClearType text is harder on the eyes than crisp, well designed pixel-based screen fonts. I haven’t seen anything in OSX or XP that improves my ability and comfort in reading text or other information on a computer display.

Experimental data does not support your claim:

http://blogs.msdn.com/fontblog/archive/2005/12/13/503236.aspx

Eam wrote:
There are zoom tools for printed materials too.

Yes, I believe it’s called a “magnifying glass”. :smiley:

Have you correctly configured your ClearType? Every screen is different - it’s not as simple as checking the little box.

http://www.microsoft.com/typography/ClearTypePowerToy.mspx

In re the main post … I played around with one of the Sony Readers the other day, which is supposed to be really awesome. I thought it was just “meh”. They claim to have ~170dpi, and whatever they are using to antialias their fonts is impressive, but between the two it still isn’t perfect yet.

And, it may just be me, but the background color was off. The dirty grey you see in all the promo shots is right on. I know that a white would only highlight the dot pitch and eff with their antialiasing, but it feels like you are reading a cheap pulp novel. The flat tonality is just a little offputting. Maybe a small amount of noise would help?

(And oh yeah, the unit is slooooow. Annoyingly so.)

Roddy,

Yes, I know. The reason why it works on that monitor is the high DPI and small dot size, so there isn’t any visible colour-fringing. The text is just beautiful and definitely sharp. I’m seriously thinking of trying to find a used 22" CRT somewhere for cheap and running it at 2048x1536.

A friend of mine uses a 20" CRT at 1600x1200 with ClearType. I was surprised how neat it is with fonts of 12pt and higher, because, like steveth45, I find CT fonts very blurry and tiring on LCD monitors at the same resolution and very hard to read at 1280x1024 (actually, I can’t stand looking at LCD’s either way, though that’s a different story).

But, this was a beauty. Apart from the small size of just about everything in XP (is Vista better?), the fonts looked very natural. I imagine that 2048x1536 on a high-quality CRT with ClearType would be awesome. For those of you who are fortunate enough not to have their head explode from looking at LCD monitors, you’re probably there already, and for that I envy you.

I really should read the sites I link to… here’s a GREAT entry from the fontblog on the history of Windows and Mac monitor DPIs:

http://blogs.msdn.com/fontblog/archive/2005/11/08/490490.aspx

AC said - “A friend of mine uses a 20” CRT at 1600x1200 with ClearType."

Cleartype is primarily designed for LCD displays and takes explicit advantage of the color sub-pixel positions of those displays. However, Cleartype also improves the quality of text on CRTs because it anti-aliases the text, removing jaggies at the expense of some perceived “sharpness”. Even though the antialiasing is based on incorrect assumptions about positions of sub-pixels, it still helps.

Also, it’s worth thinking about good old NTSC video. According to my math, a 22" TV set has a resolution of a whopping 40 DPI, yet image quality can be remarkably good. So resolution isn’t everything…

The high contrast of my laptop screen allows for much easier reading and smaller text than printed material which is subject to lighting conditions, despite the higher resolution of the latter.

Regardless, I don’t know why Tufte or anyone is so obsessed with information density. If it is for the sole reason of being able to consume more information more easily, give me a webpage at 72 dpi any day. Given a computer made in the last 5 years, I can scan through the text and pick out the information I need much quicker than I could with any printed format, be it 600 or 24 million dpi. That’s not even counting searching for certain words or chapter headings.

Higher resolution displays are already hitting the point of diminishing returns. Size is more important than dpi. It’s more about traversing, and mining information than how much you can fit in a certain number of square inches.

Another thing, the blurry ClearType text is harder on the eyes than crisp, well designed pixel-based screen fonts. I haven’t seen anything in OSX or XP that improves my ability and comfort in reading text or other information on a computer display.

There are zoom tools for printed materials too.

magnifying glasses? reading glasses?

Although it may be representing a coarser data set, the scanned sparkline appears sharper than the pixelated solid-black-on-grey example. In the screenshot, it’s hard to tell whether a diagonal is supposed to be a straight line or a series of stepped data points.

Computer displays can simulate a finer line by anti-aliasing—using tonal values as a trade-off for resolution. But that is still not the same as glossy offset printing, where you can “zoom” in and out much more quickly without losing sight of the context, just by leaning closer to the book or picking it up, or stepping into good light. Readers seldom find a magnifying glass necessary.

Another thing, the blurry ClearType text is harder on the eyes than
crisp, well designed pixel-based screen fonts. I haven’t seen
anything in OSX or XP that improves my ability and comfort in
reading text or other information on a computer display.

Experimental data does not support your claim:

http://blogs.msdn.com/fontblog/archive/2005/12/13/503236.aspx

The data also reveal substantial individual differences in performance suggesting ClearType may not be universally beneficial to information workers. Dillon et al, 2006.

Not all studies have shown that Cleartype is easier to use, read, or understand. Nor has this been shown for all types of data (small paragraphs vs. lines of code vs. long texts). Moreover, screen size, dpi, and type of screen (LCD, CRT, etc…) have not all been compared. Nor have all fonts been compared (nor has font familiarity been considered). Finally, while some studies have shown Cleartype is better in certain situations, they also point out that individual preference is a far larger factor than the (small) gains produced by universal use of Cleartype. Amongst those who dislike Cleartype, speed and comprehension are much worse.

It is presumptuous to assume Cleartype is universally better. Studies are still relatively limited and preliminary, and those who extrapolate too much from them may suffer as a result. Is it worth improving legibility by 2% for 90% of readers if 10% of readers suffer a 30% loss of legibility? Those 10% will stop using the product, and the 90% won’t notice difference.

The resolution differences between on-screen visuals and print are often much less than it would seem, and computers have some theoretical compensating factors, namely temporal resolution (I say theoretical because animated data techniques are rarely executed effectively).

While computer system metrics may assume 96 dpi on a PC, the resolution on my little lappy is 142 dpi. Some new 1920x1080 laptop screens are closing in on 200 dpi. And I’ve seen 300 and 400 dpi LCDs used for medical and engineering imaging. Toshiba could have shipped 300 dpi laptop screens five years ago if there weren’t terrible usability and aesthetic problems with Windows at such high resolutions.

And then you need to keep in mind, even with fabulous 2400 dpi output, offset-printing color reproduction uses screens (a pre-computer geometric method of optical dithering), and ends up reproducing photos at the equivalent of 150 dpi (in printing terms, it’s 150 lines per inch). So if you are looking at a color photo in a magazine, you are actually seeing about the same amount of resolution that you do looking at a photo on a modern laptop screen.

Where paper-printing excels of course are typography, although the example you chose from Tufte is not persuasive, as the data represented would appear to be sparse, with the line graph giving the impression of more data points than are likely to be present. Ironically, the computer sparklines example appears to actually contain more data in each sparkline than the Tufte example.

If you were to go back to the early Tufte books and find the example of the Swiss geological map you’d see the true communicative, data rich power of line-art on paper. I doubt there is any computer map ever made that can compare. However, this is a special case, as most data is not this rich, or designed well enough to be interpreted effectively with this level of data density.