ELI5- why is it so difficult to take a decent picture of the moon on your phone?


Edit: I forgot to add a message. It’s so pretty when you look at it with your eyes but when you take a picture of it through your phone, it is a pathetic white blob.

In: 33

The moon is far away, the moon is small compared with the whole area covered by the camera, your phone tries to be smart but it isn’t as smart as your brain.

Why is your brain smarter than a phone? When looking at the moon over the horizon your brain will enhance the moon and make you think it to be much bigger than what it actually received on your eyes. Kind of a funky zoom feature.

Your phone software tries to get the object it thinks is important to be non-blurred. It could be possible that when looking at the phone it looks very sharp and big. And when pressing the button the phone moves a bit and the phone tries to refocus. And then boom, your picture is taken sharp close by while the moon is far away.

So get a tripod, lock the phone, disable the smartness and zoom in.

Two reasons. The first is that digital devices store colors as numbers, with no way to display colors “between” two numbers. So if you have an object which is textured in many very close shades of white (or black, or whatever), the picture won’t be able to capture the gradients between those colors. It’s sort of like how a topological map would make a hill look like a series of steps instead of, you know, a hill.

The second is that our eyes see the moon as much larger than it actually is due to an optical illusion. I don’t remember quite how it works, but when we see bright objects against darkness they just look bigger to us, probably so we could pick out eyes reflecting light in the dark while hunting. When you just take a picture and look at that, the effect is lost, so the moon looks its actual size.

There are multiple problems. One is the moon is quite small and the phone has quire wide-angle lenses so you will always get a small moon.

The other is exposure. The moon is a lot brighter than the surrounding sky. The automatic exposure control of a camera has to in way guess what you intend to capture in the image. Capturing a single small bright area against something dark is not what is commonly done so the camera will likely set the exposure so the moon is to bright and the result is just a white blob.

So you need a camera app that is designed to capture the sky or have a manual setting to get the exposure right. If you do that you can capture the moon with correct exposure.

Another thing that is a good idea is to have something that holds the camera for you. The image quality in low light conditions is better with a long exposure time. If you hold it in your hand there will be some vibrations so the result is better if something holds the camera still for you.

You can look up tutorials online for how to do it. Just sear for “how to take pictures of the moon with a phone” and you will find one for your OS

So the moon will always be small with a phone image, you need a lens with more magnification to make it large. But you can take decent images of a larger part of the sky with stars with a phone.

The reason it’s harder on your phone versus another camera, is that phone cameras tend to have extremely wide lenses, 8mm. The professional photographers who take pictures of the Moon use extremely long lenses, over 200mm, and one effect of using a longer lens is it a compresses the images so things that are further away look less small than when you’re on a very short lens.

Try taking a photo tomorrow at sunset, as the moon rises. It’s a full moon so moonrise should be the same time as sunset. The moon is in direct sunlight, so it’s going to be way overexposed if you take a photo on auto settings at night.

The size of it in the photo is going to depend on the field of view of your phone’s camera. Unfortunately cell phone cameras are optimized for taking photos of much closer objects, so there’s not a whole lot you can do.