Friday, September 10, 2010

Photographing stars and star trails...

The east coast of Florida is one of my favorite locations to photograph. As often as I've shot there, I have never photographed it at night. It's more beautiful than I ever could imagine. It's amazing how many stars there are out there, and how many more can be appreciated by just taking a photograph.

You can make a photo like the one above by using a fisheye or wide-angle lens to capture as many stars as possible. You can also take many consecutive photos and stack them to create a single photo  to create star trails as shown below.

I used a 16mm fisheye lens, f/4 and a 30 second exposure. For consecutive exposures to create the star trails, I used the interval timer feature in my camera (Nikon D3s). Your camera may have this feature, or you can use an intervalometer. The interval timer on my camera is set to record one exposure (30 seconds) every 33 seconds for as many shots as my battery will allow. Noise reduction is turned off to allow for consecutive shots, and image review is turned off to save battery life. I focus manually and find it helpful to make several test shots to determine ISO, and verify the overall exposure.  Experiment with longer exposures, however keep the interval between exposures consistent, or there will be gaps in the star trails.

Here's what you will need for star trails...  A clear night, tripod, interval timer, flashlight, a location without a lot of noise pollution and a compass. You can look for Polaris, the north star, or just use a compass to locate north (or south)  if you wish to shoot circular trails. I use my iPhone compass, it works great!

If you want to experiment, you may be able to do this in your own backyard, as I did with the images below. This is good practice for any clear night.

Star trails don't always have to be recorded as circular, there are no rules! The photo below was taken with an 8mm circular fisheye with the camera facing up in my driveway.  I had to rescue both cameras as it started to rain. Even on this "clear" night, clouds rolled in quickly, so keep an eye on the weather!

You can use a script in Photoshop to stack the images. If you are using Photoshop extended, choose File>Scripts>Statistics, and set the stack mode to Maximum. I make any tweaks and adjustments to the stars in camera raw and convert the images to tif files. You might want to experiment with other software stacking programs, PC users can look into Startrails. You can also blend the images in Photoshop by stacking and using a blend mode of Lighten. (However this will take a while if you have a lot of images)!

I'm just getting started with stars and star trails, and I'm very excited about it! I like the way the stars look in the first image, but the star trail images are so interesting too! Don't forget to consider an interesting foreground element. I used HDR for the foreground in the last two images to create a better balanced image. Have fun shooting!