Shooting the Moon
Unlike the sun, the moon rises in a different azimuth (direction) every evening.
The azimuth can vary as much as 15 degrees from night to night. Also there is
only one or two nights a lunar month when the moon is near the horizon and there
is enough light in the sky to record as deep blue and not black or too bright
The moon rises about 51 minutes later each night. (24 hours x 60 minutes / 28
days) and it travels about 14 degrees per hour. You definitely need a moon program
to determine where it will rise if you have to line up things in your shot with
the moon rising or low on the horizon. You may get only one chance at it a month
when there is the right sky color. The sky will be much darker or black for
the same moon height over the horizon on a following night.
If you can use the moon higher in the sky you have more days to get the moon
with good sky color. If you can matte in the moon in post production, you have
even more latitude. Shoot the moon against black and matte it in. It will have
better detail few days from exactly full. Moon transparencies are available
from Cal Tech in Pasadena and NASA.
Exposure. The moon is pretty bright. A 1 degree spot meter would not read a
whole moon which is only 1/2 degree in diameter, the same as the sun. Reading
the moon with a 1 degree spot meter would over expose the 1/2 degree moon by
two stops which would be a start for exposure tests if you want detail. If you
just want a white disk you can over-expose it a lot.
Also consider that the moon will rise at an angle to the horizon similar to
the sun (90 minus your lattitude), but not exactly because of its more erratic
motions. (See Sunrise
and Sunset Position)
As with all unusual problems I suggest some tests before hand if possible. Video
camera tests would be helpful if shooting film.
For a great moon and sun position program, see SKY for Windows Abbey Information
Systems http://LAbbey.com/SkyDemo/ or
404-633-7446 or LAbbey@LAbbey.com
Here is some great information from Duraid Munajin of Montreal Canada. Thanks.
The exposure of the moon is similar to exposure of the earth in daytime. The
same light source is hitting it. You can use the "sunny 16" rule as a basis
for exposing a full moon on a clear night. Keep in mind the moon is very light
and a "sunny 22" rule might be more appropriate. For a narrative film where
the moon appears in the shot as a light source it should be over exposed by
a stop or two. (This is not moon light on the earth which is very little film
and video exposure wise.)
When thin clouds pass the moon this exposure is still OK.
Shooting the moon on the horizon is a different story. You can determine exposure
by comparing something else in the scene with a spot meter and judging what
brightness the moon should be in comparison. (Remember the 1/2 degree moon size
and 1-degree spot meter acceptance angle problem.)
Ron says, don't expect good results without testing your procedures before a
critical shoot. Practice. Exposure of sun balls and sunsets also takes practice.
The "sunny 16" rule says. For a bright sun lit scene, set the lens at F 16 and
set the shutter speed equal to your film ASA. To determine the "ASA" of your
camcorder or digital camera, you need a light meter and know how to use it.
Make sure the video camera is set at "0" dB gain. This is time and effort well
spent because there is a lot of great material out there about still photography
applicable to video and motion picture work.
© Copyright 1999-2004 Ron Dexter. All Rights Reserved.