- cable release
- Photoshop (or similar editing program)
Step 1: Exposing
In order to get the proper exposure for all three areas of the photograph, the background, mid ground and foreground, you actually have to take three separate photos. The easiest way to do this is to use a tripod and cable release for your camera.
Once you have figured out the crop you want, first expose for the sky, or background. This is where the cable release will come in handy. Because the exposure time is going to be longer than a simple snapshot to capture all the details in the stars, you're not going to want your camera to move at all, and the cable release will prevent any vibrations or camera shake that might be caused by the user. Don't worry about the rest of the photograph being underexposed, just concentrate on the exposure you want for the sky.
After you've exposed for the sky, get ready to take a separate photo for the mid ground. Be sure not to move the tripod or lens in any way, the photographs need to be from the exact same positioning and crop for this to work.
*In this particular example that I am showing, I actually created some of the light on the mountain to lessen the exposure time for the mid ground. To do this, I had a friend standing behind the van out of view with a flashlight shining it back and forth on the mountain to give it some shadows and brighten up the exposure.
Once the exposure for the mid ground is taken, continue on with exposing the foreground in the same way. Be sure to expose for your main subject, which in this case, is the van.
*To make the tents in the background look like they are glowing, I had someone sit in each tent and flash a portable strobe a few times for each.
Final result: 3 separately exposed photographs.
**Unfortunately I was unable to find my original "mid ground" photo, which is why there are only two exposures shown above. :/