Edit title – 3,6 times bigger than visual of the Moon we see here on the Earth surface?
In: Mathematics
The pictures of the Earth from the Moon looks very large. You are probably mistaking how tiny the moon really appears. Take a picture of the moon with your phone, and you’ll see that it is really tiny.
At night, try holding your hand out at arm’s length, and use your thumb to measure the distance between two stars.
Now, bend your arm so that your hand is closer to your face, perhaps about half arm’s length. Now you use your thumb to measure the same distance between stars?
It seems like your thumb has changed size, relative to the stars, just because it’s nearer!
It is the same whenever you are using nearby objects to measure distant objects. You can’t just eyeball them and not know the distances to each.
Look at a picture on your phone. Look at that same picture on your computer. Now, look at it full screen on your computer.
It changes sizes. There is no ‘natural size’ for an image. As such, you need to normalize the size of objects in an image. You can do this with a reference object. Let’s say a lego figure held at arm’s reach from the camera. If we have two pictures and want to compare them, we can scale them bigger or smaller until the lego figures appear the same size.
Your brain sort of automatically does this when looking at pictures, but without a reference object, it’s basically impossible to get any real idea of relative sizes.
How do you know it is not?
What images with the same focal length of the same film size have you compared the images to? Or compared the same focal length equivalent on smaller film size.
How large the moon is in the frame depends on the focal length and film size. compare how the moon looks on a cellphone image compared to a camera with a lot of magification. It is a small dot vs a full-frame moon.
The 3.6x is only the radius difference. The area of the earth in the sky is the cube of that so 13.4x larger area.
3.6 times larger than what? And why should it be 3.6 times larger? How large something appears in a photograph depends on the distance to the object and the focal length. Change the focal length, get a different size – this is the principle behind zoom.
Latest Answers