Do Not Adjust Your Sets

Here's something mildly diverting... although - at risk of sounding like I'm trying to get my excuses in early - whether it makes any real sense might depend on the characteristics of the screen on which you're reading it.

I'm currently in Edinburgh for the IAB, but took the opportunity to pootle off this morning to the SNGMA, where they've a Bridget Riley exhibition.  (It's small, but very good.  Well worth a visit, I'd say, though perhaps not if you've got a hangover.)  One of the paintings on show is this one:

It's called Rattle, and it's a touch over a metre and a half high, by almost four metres long.  It's a series of stripes, each of which is constituted by alternating sequences of diagonals in red bordered with green (which look a bit orange), and red bordered with blue (which look a bit pink).

But here's the thing: the intensity of the colour seems to depend on the direction of the diagonals.  To my eye, the bends sinisters (top right to bottom left, as we look at it) seem to have a much deeper and more vibrant hue than the bends dexters.  I wondered if it was just my eyes, but I asked a couple of other people who were there, and they agreed.  It's just occurred to me that maybe they were just being polite, but I'll take them at their word.

The picture I've just used is one I downloaded; here's a detail from the painting that I photographed myself.  The effect is lost a little in translation from reality to camera to blog, but I think it's just about visible in the two "pink" stripes; the lower one, to my eye, seems to be more intense than the upper one.  Oddly, the bends dexters in the "orange" rows now look to be the more intense to me here, which was not the case when I looked at the painting directly a couple of hours ago.  That in itself is possibly worth noting.

I wondered if the effect would be preserved in black-and-white; and I think it is.

Look at the top three rows in the reproduction on the right here; the top one, the third, and the fifth one down are pink-looing in real life, and the one between them is orange-looking.  But the top row and the third do look to be different even here - darker in the bend sinister than in the bend dexter.  Rows 4 and 5 look to be more similar to each other than rows 3 and 5.  Had I not seen the colour version, I think I'd be inclined to guess that 4 and 5 were the same colour in real life, and 3 different from both.

Or maybe I'm just trying to persuade myself now.  It's a bit hard to tell.

So that's mildly interesting.