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Comment by cryptoz | Hacker News Reader

There's a middle ground here. I saw the northern lights with my own eyes just days ago and it was mostly grey. I saw some color. But when I took a photo with a phone camera, the color absolutely popped. So it may be that you've seen more color than any photo, but the average viewer in Seattle this past weekend saw grey-er with their eyes and huge color in their phone photos.

(Edit: it was still super-cool even if grey-ish, and there was absolutely beautiful colors in there if you could find your way out of the direct city lights)

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The hubris of suggesting that your single experience of vaguely seeing the northern lights one time in Seattle has now led to a deep understanding of their true "color" and that the other person (perhaps all other people?) must be fooling themselves is... part of what makes HN so delightful to read.

I've also seen the northern lights with my own eyes. Way up in the arctic circle in Sweden. Their color changes along with activity. Grey looking sometimes? Sure. But also colors that are so vivid that it feels like it envelopes your body.

> The hubris of suggesting that your single experience of vaguely seeing the northern lights one time in Seattle has now led to a deep understanding of their true "color" and that the other person (perhaps all other people?) must be fooling themselves is... part of what makes HN so delightful to read.

The H in HN stands for Hubris.

They did say "the average viewer in Seattle this past weekend", not "all other viewers".

Then again, the average viewer in Seattle this past weekend is hardly representative of what the northern lights look like.

The person they were responding to was saying that the people reporting grays were wrong, and that they had seen it and it was colorful. If anything, you should be accusing that person of hubris, not GP. All GPS point was, is that it can differ in different situations. They used the example of Seattle to show that the person they were responding to is not correct that it is never gray and dull.

The human retina effectively combines a color sensor with a monochrome sensor. The monochrome channel is more light-sensitive. When the lights are dim, we'll dilate our pupils, but there's only so much we can do to increase exposure. So in dim light we see mostly in grayscale, even if that light is strongly colored in spectral terms.

Phone cameras have a Bayer filter which means they only have RGB color-sensing. The Bayer filter cuts out some incoming light and dims the received image, compared with what a monochrome camera would see. But that's how you get color photos.

To compensate for a lack of light, the phone boosts the gain and exposure time until it gets enough signal to make an image. When it eventually does get an image, it's getting a color image. This comes at the cost of some noise and motion-blur, but it's that or no image at all.

If phone cameras had a mix of RGB and monochrome sensors like the human eye does, low-light aurora photos might end up closer to matching our own perception.

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