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Seeing Octarine

Okay, this is something weird that I wonder if other people also see.

When I see a strong rainbow in person, (but not in photos) I see it as dark red, red, orange, yellow, green, cyan, blue, indigo, dark violet... and one more faint band of lighter color that I can only describe as sort-of-but-not-really pale yellow-green.

Does anyone else see that faint pale inner band on rainbows?



( 12 comments — Leave a comment )
Sep. 24th, 2007 02:05 am (UTC)
The color sounds like roughly the complement of the dark violet. Could it be some kind of psychophysical contrast artifact?

It doesn't rain much where I live, so unfortunately I can't recall whether I've seen anything similar myself.
Sep. 24th, 2007 02:52 am (UTC)
This... is a posible explanation. A trick of the eye, where any eye movement makes the eye see the color complement where it first saw the violet. I looked at this rainbow pretty thoroughly, and thought I saw the extra band seperately, but it was so faint, maybe I was fooling myself with persistence of vision.
Sep. 24th, 2007 02:34 am (UTC)
I have seen a faint, pale, inner band on rainbows... but to me, the band looks more reddish than yellow-green.

I'll have to look again.
Sep. 24th, 2007 02:35 am (UTC)
If I understand correctly, most rainbows are actually double-rainbows, with a fainter second bow with reversed colour order. Could this have been that?

Eye artifact suggestion does sound plausible too, as the eye works partly by looking for changes in intensity in both space and time (for better edge and motion detection/fixed noise rejection).

Sep. 24th, 2007 02:35 am (UTC)
Caveat is that both of these should show in up good-quality photographs of rainbows.
Sep. 24th, 2007 02:47 am (UTC)
Yeah, I considered this idea too, but I spent about 15 minutes watching this rainbow, and I didn't see any red or green between the violet and the last band.

I do see a different odd effect in rainbow photos, which is that the area inside of the rainbow arch is lighter in color than the outside of the arch. Even several degrees away from the bow itself.
Sep. 24th, 2007 02:49 am (UTC)
Oh, and yes, I did see a second reversed arch a number of degrees to the outside of the strong primary, if that's what you were thinking. That's not what I was referring to, though.
Sep. 24th, 2007 11:20 am (UTC)
Supernumiary Rainbows (as per wiki naming)

Yeahup, they appear when the light is very bright.

The outer rainbow is caused by a secondary reflection inside the raindrops.

Each reflection looses some of the luminance and the bands become wider spaced.

A good number of rainbow picture showing 2 rainbows will show ghosts that look like camera artifacts of purple and green inside the primary rainbow.

Those are the supernumiary rainbows overlapping with the primary and each other.

Wiki has a good writeup on it. And a really great picture showing the effect:

- krin
Sep. 29th, 2007 08:32 am (UTC)
Re: Supernumiary Rainbows (as per wiki naming)
That's it! I was seeing the first pale band of the supernumiary rainbow!
Sep. 24th, 2007 07:14 pm (UTC)
Secondary phase wave reflection?
You're not the only one that sees this -- I do, too, usually on very bright days when there's a chance of a double rainbow -- sometimes the 'double' will fade into the yellowish-green when the clouds intervene for a little bit.

Oct. 22nd, 2007 11:31 pm (UTC)
Happy birthday, batbat :) I hope your day was sweet *HUG*
Oct. 27th, 2007 10:55 pm (UTC)
Quite interesting post. Thanks for bringing it up. Also keep an eye out on other types of sky coloring. Many don't relieze how many times colors other than rainbows show up.

In fact on my web shots photos (http://community.webshots.com/user/mbridge1965), I'll be posting pictures of some I've got over the years.

- Shado
( 12 comments — Leave a comment )