Shooting Stars: How to Photograph Meteor Showers
By Stan Sholik
Photographing meteors during a meteor shower isn’t as difficult as you may think. All it requires is a little advance planning, a little preparation, a little luck and the camera gear that you already own.
This is a composite of five captures: four meteor streaks and the foreground hillside. The image shows the meteors radiating from a point that lies close to the constellation Perseus. Nikon D800E, ISO 1600, 25mm f/2.8 Zeiss ZF, 20 seconds at f/2.8 each capture. ©Stan Sholik
Meteor showers occur for a number of reasons, but the predictable showers happen when the Earth passes through the remnants of a comet or through its tail. Knowing when these meteor showers occur is the easiest part. There are three major events visible in the US: the Perseid shower in August; the Leonid in November and the Geminid in December. The International Meteor Organization publishes detailed information and dates on its website, www.imo.net.
These events are named for the closest constellation from which they seem to radiate: Perseus for the Perseid, Leo for the Leonid and Gemini for the Geminid. Picking out these constellations from a dark sky full of stars can be tricky. There are laptop and smartphone apps to help, but my favorite astronomy app is StarMap 3D Plus on my iPad. Not only does it have all of the needed astronomical visuals and information, there is a setting that displays the information in red on the screen. The red display preserves your night vision far better than the bright white of a laptop or smartphone screen.
Most meteors during the night are faint streaks in the sky. The darker the sky, the more visible the meteors. That means finding a place where the sky is dark. The best website I have found for this is cleardarksky.com. It lists thousands of locations in the US, Canada, and Mexico and updates conditions daily for cloud cover, atmospheric transparency, darkness and several other factors. It’s a good resource to check before you head out hoping to see meteors. And of course, the presence of the moon, combined with other atmospheric factors, can severely limit your ability to see meteors.
I prepare my camera gear before I leave to save myself the struggle and the possibility of mistakes trying to load film cameras and adjust settings on digital cameras in the dark. I take as many cameras as I have tripods and fast manual-focus wide angle lenses.
Although you know the point of origin of the meteor shower, it’s impossible to predict where in the sky the meteorite will strike the atmosphere. Fast f/1.4 to f/2.8 wide angle lenses with focal lengths from fisheye to 28mm are the best choices. I prefer manual-focus lenses because the infinity setting is at one end of the focus scale and is easy to set in the dark. The infinity position on an autofocus lens is never obvious.
Because the Earth is rotating, after a certain exposure time the stars are no longer points. I use film cameras for long exposures on Bulb (with a locking cable release) or T (if your camera has this) settings to capture circular star trails and straight meteor streaks. Faster film captures fainter streaks, but results in larger grain. I compromise on ISO 100 transparency film, pushed two stops to ISO 400, and don’t even think about reciprocity.
I prefer film cameras for doing long exposures that show circular star trails with a straight meteor trail (circled). The larger the lens field of view the more likely you are to capture a meteor trail somewhere in the sky. This is taken with a Nikkor 16mm f2.8 fisheye lens at f2.8 and an unrecorded exposure time using a Nikon F100 camera and ISO 100 film pushed to ISO 400. ©Stan Sholik
I use my digital cameras for photos of stars without streaks and hopefully with a meteor. There are precise formulas for determining the optimum exposure based on the focal length of the lens and the height (azimuth) of the star in the sky. But there is an easier, although less precise, method that I use. I divide the lens focal length into the number 500 to determine the number of seconds to expose the image. For example, with a 25mm lens that is 500/25=20 seconds. Close enough.
As with film, the higher the ISO setting on your digital camera, the better the chance of catching a faint meteor streak, but the greater the noise. With my Nikon D3S I use ISO 1600 and turn off Long Exposure Noise Reduction, since the camera’s noise is low enough at that setting and I can keep shooting without waiting for the dark exposure. With the D800E, I also use ISO 1600, but with Long Exposure Noise Reduction turned on.
The less you handle the camera controls, the less the chance of disappointment later. These Nikon cameras make the exposure process easy. Both have a built in intervalometer. The intervalometer allows me to set up the cameras (before I leave) to make unattended exposures for a specific duration (20 seconds with a 25mm lens) every 25 seconds on the D3S for as many hours as I choose. For cameras without a built in intervalometer, the Promote Control unit from Promote Systems includes an intervalometer and adapts to many digital SLRs.
If I’ve planned well and prepared my equipment properly, and luck is on my side, the actual meteor shower is a time to relax and enjoy the show. I try to choose a location where I have an unobstructed view of a large area of the sky, but with a foreground object in the frame to give a sense of depth and scale. The foreground object could be a tree, hillside or distant mountain. Any moonlight will expose it during a long exposure, or it will silhouette against the stars on a moonless night.
I could have used a little more luck for this year’s Perseid event on August 12. The Clear Dark Sky website predicted a 20-percent cloud cover around 2 to 3 a.m. and clearing as morning approached, with average transparency. Unfortunately the cloud cover reflected a lot of light from the crescent moon and the viewing wasn’t as good as it had been in years past. But there were meteors and I was lucky enough to capture them both on film and digitally.
With exposures of 30 minutes to 2 hours with the film cameras, there aren’t many frames to edit looking for meteor streaks. If your luck holds, there will be a few good frames.
With the digital captures, at approximately two captures per minute for four to five hours, there will be hundreds. Again, with luck, there will be several with meteor streaks. With a lot of luck you will have captured a few very bright meteor trails, but most will be faint. The bright ones are usable with minimal processing, and there are a few tricks to enhance the faint ones.
A particularly bright meteor trail from this year’s Leonid meteor shower. The image is a composite of the meteor trail with another capture from the same camera in which I had painted in the foreground hillside with a flashlight. Nikon D800E, ISO 1600, 24mm f2 Nikkor, 20 seconds at f/2. ©Stan Sholik
After doing what I can to enhance an image with a faint meteor trail in Lightroom, I bring the image into Photoshop, duplicate the layer and try different Blending modes. Overlay mode seems to work best most of the time, along with a curves adjustment.
I have yet to be lucky enough to capture more than one meteor trail in an image, but that doesn’t mean that your final meteor shower photo should only include one. Since your digital camera was locked down on a tripod, the only movement was that of the Earth itself. With one image as your base image, stack other captures with meteor trails from the same camera setup on separate layers above it. Work on these layers from the bottom up.
Adjust the layer opacity of a layer to see the layers below, rotate the upper layer to align the stars over the stars on the lower layer, then mask out everything except the meteor trail on the upper layer. When you are done with the topmost layer, you will have a sky full of meteor trails that radiate from the origin point of the meteor shower. A wondrous image to create and all it took was a little advance planning, a little preparation, a little luck and the camera gear that you already own.
Stan Sholik is a commercial/advertising photographer in Santa Ana, CA, specializing in still life and macro photography. His latest book, Lightroom 4 FAQz, published by Wiley Publishing, is available this fall.