Photo Hints Sun and Moon

Have you ever taken a picture of the moon and wondered why it looks so tiny?

When the moon is close to the horizon, it LOOKS like it is bigger than when it is up in the sky. However, this is just an optical illusion!

First a couple quick facts:

When you use a 100mm lens, the moon or sun will take up, typically, about 1mm on the film. A 200mm lens will use up about 2mm.

The sun & moon are moving relative to your position. This means you shouldn't use a long exposure. If you use too long an exposure, they stop looking like a circle and start looking like an smudged oval due to their movement. See table below

Lens focal length

Maximum exposure

Size on film

% of height of 35mm film

% of height of 4x5" film


3 seconds

0.35 mm




2 seconds

0.5 mm




1 second

1 mm





3 mm





6 mm





10 mm



Notice that for a 35mm film, if you want the sun or moon to be a significant object, you need a 300-600mm lens. On 4x5 film, you need a 1000mm+ lens to do the soon or moon justice. You could, of course, crop the 4x5 camera - if you crop it to the size of a 35mm camera, then your standard 210 lens will give the same size moon as a 210 lens on a 35mm camera. But that isn't why you use a 4x5 camera! The other "of course" is that, if you are going to make a 8'x10' enlargement, you aren't going to use a 35mm lens and have great quality. Instead, you will use a 4x5 or better camera. a 300mm lens will give you a 3" moon. A 1000mm lens will give you nearly a 10" moon.

Don't stare at the sun, even in an eclipse. Even in a sunset. Even hidden by cloud. You could permenantly damage your eyes. There are tricks to getting the sun in the picture - if you can see the settings the camera is picking without looking in the viewfinder, you can move the camera until the highest reading is shown, this places the sun in the center of the photo, or put on a welding helmet and look through that. Yes it's ackward, but you want to keep your eyes don't you? If neither of these work, there is a simple solution DON'T TAKE THE PICTURE. No picture is worth ruining your eyesight. Think about it. You work hard to get that picture, and then you can't see nice pictures properly the rest of your life! So, the only time to do this is when you are on your death bed and you want to take one last picture for posterity, and you have only seconds to live, not enough time to get a welding helmet! OK, then and only then it is OK.