7

CHAPTER
NIGHT AND LOW-LIGHT PHOTOGRAPHY / The Nighttime Sky

1. Set the camera to manual mode.


2. Set the ISO to 1600.


3. Set the aperture to f/5.6.


4. Compose the image through the viewfinder.


5. Set the shutter speed to bulb.


6. Use the cable release to take a 90-second
   exposure.


7. Check the exposure on the back of the
   camera. If the image is underexposed, try
   twice as long. If the image is overexposed,
   halve the shutter speed and try again.
   Once you have determined the proper exposure
   using a high ISO of 1600, you can start to work
   out what the exposure settings need to be for ISO
   100, and in doing so this will give you a lot slower
   shutter speed which will allow for the movement
   needed to capture the star trails.

There are two methods used to capture the very
long exposures needed to produce star trails. The
first is to just set the camera up, open the shutter
with a cable release, and leave it open for the
length of the capture. The problem is to deter-
mine exactly how long to keep the shutter open
and what aperture and ISO to use to get a proper
exposure. A good method is to use equivalent
exposure math to your advantage. By using a fast
shutter speed, a middle aperture, and a high ISO,
you can get a good starting exposure. From there,
you can change the shutter speed and ISO until
you have the length of the exposure you want.
Here are the basic steps (but keep in mind that
your starting numbers will be different from mine):

ABOUT THIS FIGURE A screen capture of the time-lapse movie playing.

7-17

Equivalent exposures are discussed

in Chapter 2.

x-ref