For example, I’m sitting on my front porch which overlooks the town. Miles away I can see streetlights, signs, etc. How does the source project light to my location, yet doesn’t illuminate my location?
Holy moly friends, thanks for the awards and stuff. I didn’t think this question would spark so much interest, lol. I am thoroughly grateful for all your replies.
In: Physics
There are a lot of things going on, but here a few:
1) our perception of light is non-linear,
Meaning that something twice as bright (twice the light photons) appears just a “shade” lighter.
But it also means that something super dark just needs a little bit of light to visually become much brighter.
2) the sun is _really_ bright – just remember that street lights during the day are hardly noticeable when on, but at night they can be seen from miles away.
3) bouncing light (reflecting against walls etc) is actually also pretty bright, we just don’t think about it. Just remember your entire house is lit by sunlight bouncing around through a few windows during the day. You know those weird umbrellas at photo shoots? Those are only there to bounce light around that’s already there. Lots of outside shoots use bog white reflectors to just bounce sunlight around – don’t even need lamps!
Also remember seeing streetlights on during the day; they look super dim – almost everything around you is as bright as those lamps just from the sun reflecting on random surfaces.. You’re effectively as bright as a lamp yourself!
4) another perceptual thing: humans are really good at zooming in on details in the distance. making them look bigger in our head. just look up a model scale of earth and the moon. The moon is way smaller and way further away than you would think, it looks bigger in the sky.
——-
This all combined has the effect of making small lights in a relatively dark area to be bigger and light up stronger than you would think. Stuff like leds on an old stereo are actually pretty strong because they need to be visible in the daylight. In the dark those things can light up a room. You can see lights from a distance because they stand out and our eyes are really good of noticing small bright things. But also, you’d be surprised how much a small light actually does light up surroundings, during the day it is completely washed out by the sun, and we also just never notice it.
Tl;dr non linear perception, lights are pretty bright but the sun blows everything away during the day – and actually small lights are lighting up stuff more than you’d think
It’s a long rant but i think it’s a super interesting, phenomenon – I’ve had a decade of light rendering experience and one thing I’ve learned is that what we see, what we think about and what we notice are completely different things.
Latest Answers