2006-03-01
Re: Computers are Interesting, Part Two
Oh no. I've reached the point where I'm commenting on other people's blog posts on my weblog. I was writing a comment to this post by Claire over at Urban Honking's Universe blog, but then I kept writing, and then, oh god, here I am.
Almost everything in the natural world that casts light does so from above; so, nearly everything we see has a shadow under it. Since it's an almost-universal feature, the visual cortex very likely processes this early in the pipeline to help distinguish separate objects and gauge size and distance. Adding a shadow to the bottom of a window is an easy and cheap way to make it stand out. But shadows can swing left or right depending on where the sun is; there's no natural direction there.
You're close when you suggest that the shadow placement on computer windows is due to the way we read, but I think there's really nothing psychological about it. Pixels in the window were indexed from the top-left corner of the window, so if you put the shadow on the bottom (which you would anyway) and to the right, you don't have to worry about a one-pixel offset: the origin point for the window is the same whether it has a shadow or not. As for why they chose the top-left corner for the origin: that's because pixels in a frame buffer are traditionally ordered in the same left-right, top-down style of CRT scan lines, which in turn follow the manner of Roman text we've inherited. (I suddenly feel like James Burke.)
My hunch is that the shadows on cheesy web buttons lean to the right only because the "sun" position on the Windows or Mac OS 9 desktop is up-left, so it seemed natural for the designers to orient them that way. I doubt it has any significant psychological effect whether they go left or right, or any effect on readability.
(Also, note that the shadow on the OS X aqua "candy" button you show above doesn't actually lean left or right—it goes straight down. The Apple designers decided that the imaginary light source doesn't need a left-right orientation since they've got these fancy new composited shadows that stretch out of both sides of the window and no longer need to rely on a single pixel border.)
Now, what I'd like to see is window "lighting" that matches the time of day: shadows go straight down at noon, and shift as the day goes by. Right before sunset you've got long, gorgeous shadows streaking across the desktop, and after everything has a golden-red hue.
Or, if you're in Portland and it's somewhere between October and May, everything's just kind of grey.
Almost everything in the natural world that casts light does so from above; so, nearly everything we see has a shadow under it. Since it's an almost-universal feature, the visual cortex very likely processes this early in the pipeline to help distinguish separate objects and gauge size and distance. Adding a shadow to the bottom of a window is an easy and cheap way to make it stand out. But shadows can swing left or right depending on where the sun is; there's no natural direction there.
You're close when you suggest that the shadow placement on computer windows is due to the way we read, but I think there's really nothing psychological about it. Pixels in the window were indexed from the top-left corner of the window, so if you put the shadow on the bottom (which you would anyway) and to the right, you don't have to worry about a one-pixel offset: the origin point for the window is the same whether it has a shadow or not. As for why they chose the top-left corner for the origin: that's because pixels in a frame buffer are traditionally ordered in the same left-right, top-down style of CRT scan lines, which in turn follow the manner of Roman text we've inherited. (I suddenly feel like James Burke.)
My hunch is that the shadows on cheesy web buttons lean to the right only because the "sun" position on the Windows or Mac OS 9 desktop is up-left, so it seemed natural for the designers to orient them that way. I doubt it has any significant psychological effect whether they go left or right, or any effect on readability.
(Also, note that the shadow on the OS X aqua "candy" button you show above doesn't actually lean left or right—it goes straight down. The Apple designers decided that the imaginary light source doesn't need a left-right orientation since they've got these fancy new composited shadows that stretch out of both sides of the window and no longer need to rely on a single pixel border.)
Now, what I'd like to see is window "lighting" that matches the time of day: shadows go straight down at noon, and shift as the day goes by. Right before sunset you've got long, gorgeous shadows streaking across the desktop, and after everything has a golden-red hue.
Or, if you're in Portland and it's somewhere between October and May, everything's just kind of grey.
# posted by Dave : 1:10 PM
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Does that mean your screen will be black or at least very low-contrast at night? Or maybe it will have multiple shadows cast by different spot light sources, like streetlamps?
I was thinking it'd be dark except for the front window, kind of like expose's window select mode. And the window's light would shine on the other windows.
Two things come to mind: first, flying over a city at night, I'm always surprised just how much light comes up from the streets to illuminate the buildings. From above, they look like they're glowing. Second, when I lived in Budapest most people didn't have cable TV so they watched one of the three channels broadcast over the air. At night, the giant Soviet-style concrete slab apartment buildings would flicker with three distinct random patterns.
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Two things come to mind: first, flying over a city at night, I'm always surprised just how much light comes up from the streets to illuminate the buildings. From above, they look like they're glowing. Second, when I lived in Budapest most people didn't have cable TV so they watched one of the three channels broadcast over the air. At night, the giant Soviet-style concrete slab apartment buildings would flicker with three distinct random patterns.
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