My phone is normally worse for color gradients and contrasts than my eyes. Also, normally it has worse nightvision.
But when decreasing the shutter speed, for example in OpenCamera, I get crazy night pics.
I see that when its dark my FPS goes down, I see less frames automatically and totally cant control that.
Could this mechanism be altered, to have even less FPS but more photons in the soup to get brighter sight?
Yes, trying to hack my eyes here. “Getting used to darkness” is normally the pupils getting wider, there are quite some interesting plants to do that but I havent heard of anything altering the brains image processing.
Edit
I learned:
- in Nightsight we use the rod cells, which take longer to send a signal. That way they capture more photons, but the “FPS” is lower
- you can trick your iris naturally to stay open, like the Pirates did (some plants like nightshades also do this, applied locally)
Changing the FPS would not change your exposure. Changing the shutter angle/speed would. So does changing the aperture. We don’t have shutter speed in our eyes, but we do have an iris! Your eyes actually change your iris aperture naturally when in the dark.
You can even trick your body to change the iris on only one eye. Cover one eye for a few minutes (at least 15-20min) in a brightly lit environment then move to a rack room (not pitch black but very minimal light) and open your covered eye. Your covered eye’s iris is already wide open and you can see well from it. The other one needs time to adjust.
This is why pirates were wearing eye patches, to be able to enter the hull of the ship and see immediately without lighting up a candle. Fire is not a good idea inside a wooden ship filled with black powder.
This is why pirates were wearing eye patches, to be able to enter the hull of the ship and see immediately without lighting up a candle. Fire is not a good idea inside a wooden ship filled with black powder.
This is one theory for why pirates wore eyepatches. We haven’t found any historical evidence to confirm it. Meanwhile, we have at least a few documented cases of pirates wearing eyepatches for protecting a damaged eye.
Eyes don’t really have a concept of FPS because we don’t have shutters in the first place. The brain is just continuously interpreting what we see. And it fills in a lot of gaps: for example, we technically have a large blind spot right in the middle of the retina, and that’s why we’re more sensitive to movement in our side vision.
Cats see just fine in the dark, our eyes are just not sensitive enough to low light to be all that useful for us, but we could, if the eyes provided that input. Evolution just made it so we favored speedy and sharp vision in daylight rather than night vision, in part because we quickly developed technology (fire) to keep our areas lit as needed.
And by blind spot, you’re referring to the small portion of the vision that sees color and is much much much less sensitive to light (thus horrible at night vision) right?
No, we have a spot in each eye that is not sensitive to light at all because the space is used up by the optic nerves: https://www.scientificamerican.com/article/find-your-blind-spot/
That one does not sit in the center of the retina though, and doesn’t have anything to do with higher motion-sensitivity in your peripheral vision. The macula, which the other commenter describes, is what’s responsible for that, and it’s a different thing than the blind spot.
we technically have a large blind spot right in the middle of the retina, and that’s why we’re more sensitive to movement in our side vision.
You’re conflating the blind spot and the macula there.
We do not have a blind spot in the middle of the retina. If that were the case it would be pretty problematic for vision. What we do have is what’s called the Macula, an area of high concentration of cones and low concentration of rods. Cone cells give us highly detailed color vision, while rod cells only give us overall brightness, but are much more sensitive to light. That’s why, as you mention, we’re more sensitive to movement in our peripheral vision, and also why the center of our vision performs way worse in very low light situations. (Ever seen a faint star that seems to vanish when you try to look right at it? That’s why)
We do actually have a fully blind spot, but that one sits not at the center of the retina, but off to the side. It’s where the optic nerve enters the retina, and it doesn’t have anything to do with better/worse perception of movement, it’s just fully blind and always gets interpolated by the brain, it literally fills it up with what it thinks should be there. If you get a small object right into that spot for one eye and cover the other eye, it will just disappear.
They do. The eye doesn’t have “frames per second”, per se, because every neuron acts independently, instead of as a eye-wide “frame”. But the rod cells that your eye switches to for night vision have slower activation time than the cone cells, allowing them more time to capture photons, before telling the brain about what it saw. Just like how your camera switches to longer shutter times for night vision to capture more photons, before sending them to the SD card.
Rod cells also respond more slowly to light than cones and the stimuli they receive are added over roughly 100 milliseconds. While this makes rods more sensitive to smaller amounts of light, it also means that their ability to sense temporal changes, such as quickly changing images, is less accurate than that of cones.
Crazy! Thats it! Thanks a lot!
So its not the brain composing the image differently, but the actual chemical method the cells use to capture light. Will be hard to modify haha
Put another way conventional cameras work with cumulative sensors (at least for this conversation we can say they do) which record the total quantity of photons and their intensity being received in each spot. The shutter is the process of closing off light input and recording the data from the sensor. Technically there’s an upper limit to how much light cameras can take in, which they’d asymptotically approach I imagine.
Your eyes don’t work the same way. Each photodetector cell will send a signal when it reacts with a photon of sufficient energy (wavelength, intensity will increase the probability of reaction if im not mistaken) and send that signal to your brain. There’s a lot of other complicated stuff going on, but at the end of the day your photo receptor cells are only so sensitive, and if light is below the threshold that will activate them, you’ll mostly just get signal noise. This is true of conventional cameras too, but they are generally just tuned for a different purpose.
Animals with good night vision have highly reflective membranes behind their photo receptors to increase the probability of a photon interacting with a photo receptor, and often have different tuning on their whole eye optical systems that make them more sensitive, but also more likely to burn. There are always tradeoffs.
Eyes/the brain don’t have frames.
The way cameras work is that they expose multiple frames to create a series of still images. The slower those frames are going, the longer they are exposed to the ambient light, thus why lower FPS allows for better picture quality in low light environments.
The way to do this with vision would be to allow more light in to your eyes than normal. Larger eyes, more dilation, more rods in your eyes, and other adaptations could improve your night vision abilities. Your best bet is to look at nocturnal animals and understand how their vision is better than ours in the dark.
Hmm yes I think all of these animals simply have more rods and bigger eyes. But I also see how my brain takes longer to make single images, its not FPS but similar.
So even without improving the actual sight, having the tradeoff of less speedy sight for more ambient light per “image” would be really interesting
