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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!
You can prove it to yourself, take 2 pictures with the same lens, then compare
the size on film carefully.
First a couple quick facts:
-
35mm film is about 23mm by 36mm across the
long way (in normal view. Panoramic is wider.)
-
4x5 film (my favorite though I use 35mm
most of the time) is about 95x120mm. (the rest is a small boarder)
-
If you are using a different size, measure
one of your existing negatives to see the size.
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 for a guide
as to maximum exposures that will leave the sun & moon looking like
circles.
|
Lens focal length
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Maximum exposure
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Size on film
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% of height of 35mm film
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% of height of 4x5" film
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35mm
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3 seconds
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0.35 mm
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1.5%
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0.37%
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50mm
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2 seconds
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0.5 mm
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2%
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0.5%
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100
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1 second
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1 mm
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4%
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1%
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300
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1/4
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3 mm
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13%
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3%
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600
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1/8th
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6 mm
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26%
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6%
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1000
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1/15th
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10 mm
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43%
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10%
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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. And even there it is only going to be "significant",
it's not going to be huge. 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. In general, those shots
that show a "huge" moon beside a tree or rock are typically taken (on 35mm
film) with a 800-1000mm lens.
Don't EVER look at the sun, especially with a telephoto lens, 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 they are 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
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