Digital After Dark
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Photography After Dark Online Photo Course for Perfect Picture School of Photography Instructors: Kevin Adams and Donna Eaton Lesson 4 Night Sky Text and Photos © Kevin Adams (All rights reserved) We’ve been having fun over the past three weeks photographing all kinds of subjects at night and trying out some cool techniques. For our last week together, the fun is going to continue and we’re going to push our cameras and ourselves to the limit. My definition of night photography is taking pictures of anything outdoors while the sun is below the horizon, but my first thought is always toward the sky. I remember well all those clear nights spent outdoors when I was shooting film. I’d gaze up at the night sky in awe of the view, but irritated that I could not photograph it. Sure, I could shoot star trails, but what I really wanted to do was take a picture of the sky full of stars, just like I saw with my eyes. You just couldn’t do that with film. With today’s digital cameras, we can have our night sky and photograph it, too! Stars as pinpoints of light: ISO 1600, f/2.8-f/4, 25-30 seconds with a wide-angle lens at a dark site. Star trails: ISO 200-400, f/4, multiple exposures of 4 minutes at a dark site. Adjust settings for both according to light pollution (more pollution requires lower ISOs or shorter shutter speeds), temperature (warmer temps cause more noise in the image), and focal length (with speeds longer than 30 seconds, lenses longer than 17mm will show obvious trailing in the stars). If the lesson ended here, I’ve given you enough information to explore the world of night-sky photography. I love to see the excitement on people’s faces when they learn for the first time that they can point their digital cameras at a dark sky and make a good photograph at ISO 1600, f/4, and 30 seconds. Nothing special required. Of course, we won’t be satisfied with a good photograph, will we? We want our images to be great. So unless you are striving for mediocrity, read on. I’m going to do something a little different in this lesson. The lesson covers five main categories: Star trails, stars as pinpoints of light, planets, Moon, and meteors. However, I’m only going to discuss the last four here in the actual lesson. The reason is because I recently wrote a very detailed treatment about shooting star trails for another project and rather than condense it to fit the lesson, I thought it would be better to provide it for you in its entirety. It is included it as a supplemental document. Some of the information in it is redundant to material we’ve already covered in the lessons or other supplemental documents, but I left in in place so you would have a comprehensive guide for star trails that you can refer to as needed from now on. Stars as Pinpoints When I refer to stars as pinpoints of light (or static stars), I mean they do not show any streaking, as with star trails. In other words, we’re talking about a night photograph that approximates what we see with our eyes. This is where the new digital cameras really shine. As I mentioned in the opening statement, all my photographic life I’ve marveled at the night sky filled with stars and wished there was some way to record it in a photograph. With film, it was simply impossible. When I first started shooting digitally, noise made the image look terrible. But with the new digital cameras and their low-noise sensors, we’re finally was able to capture those awe-inspiring skies. Compositionally, shooting stars as pinpoints is the same as shooting star trails. You want to use a wide-angle lens to show as much sky as possible and you want something interesting going on in the foreground. Look for something that projects into the sky that you can silhouette, such as bridges, trees, or towers. A jagged mountain horizon line can also work well. If there is nothing interesting to silhouette against the sky, you’re going to have to find something that is already lit or that you can light paint. City skylines and most any kind of manmade lighting can make great foregrounds, but remember that the more artificial light you have, the less the sky is going to show up. If you are anywhere near a big city you can probably forget about shooting a night- sky scene. Photo 1 Nikon D800, Nikon 14-24mm f/2.8 lens, f/2.8, ISO 3200, 20 seconds Photo 2 Nikon D800, Nikon 14-24mm f/2.8 lens. Exposure for sky: f/3.5, ISO 2000, 25 seconds. Exposure for waterfall: f/5.6, ISO 200, 15 seconds (multiple exposures using LED flashlight and orange gel filter). Exposure for pool: f/4, ISO 800, 15 seconds (multiple exposures using dive light and orange gel filter). Among my favorite foregrounds for night-sky scenes are waterfalls and lighthouses. Photo 1 captures Orion and the planet Jupiter in the sky behind a lighthouse on the North Carolina coast, while Photo 2 shows a waterfall in the North Carolina mountains. You should recognize the waterfall; it’s the same one as Photo 9 and Photo 10 in Lesson 2. I shot it on the same night that I shot those. A huge advantage of shooting lighthouses over many other types of foregrounds, especially waterfalls, is that you often have the ability to move closer or farther away from the lighthouse, and sometimes even walk all the way around it. This provides tremendous flexibility with the composition. By changing your position, you can place the stars, planets, Moon, and other objects of the night sky wherever you want, relative to the lighthouse. The classic night-sky scene shows the Milky Way arching across the sky or projecting above a desert landscape. Where I live, in the mountains of North Carolina, we do not have the opportunity to shoot scenes like this because of the topography and light pollution. However, we can photograph the Milky Way and you can, too, if you go to a relatively dark site. The Milky Way might not look like it does in the middle of the Sahara, but it still looks good. And when you are shooting the Milky Way, you can often get by with a less-interesting foreground, as in Photo 3. The Milky Way creates a strong compositional element all by itself. Whenever I can, though, I try to find an exciting foreground to go with the Milky Way. Old houses, like the one in Photo 4, are one of my favorite types of foregrounds. I light painted this old house using the techniques discussed in Lesson 2. As with star trails, I like to set up camp scenes for pinpoint- star photography. Photo 5 is a blend of two exposures, one for the sky and one for the tent. For the tent exposure, I Photo 3 used a yellow gel on a camera flash and manually fired it at half power in each section of the tent. I tried it at full power Nikon D700, Nikon 14-24mm f/2.8 lens, f/2.8, first, but that made it too bright. I had a friend pose with ISO 1600, 30 seconds binoculars during the flashes so she would appear as a silhouette against the tent. Shutter speed and aperture are primary concerns when shooting stars as pinpoints. Unlike with star trails, we have to shoot exposures that are short enough to keep the stars from recording as streaks. An often-quoted formula for determining at which shutter speed a star will begin to streak according to focal length is to divide the focal length into 600. Using this rule, if you divide a 100mm lens into 600, you get a maximum shutter speed of 6 seconds before streaking shows up. My tests show that using 500 as the divider gives more accurate results. So with a 100mm lens, you could only shoot as long as five seconds before obvious trailing occurs and with a 500mm lens, you’d see trailing after only one second! With the 14mm lens that I often use, the maximum shutter speed is 35 seconds. Keep in mind that this is just a general guideline and is designed for obvious trailing. If you magnify the image, you’ll see trailing at faster shutter speeds. Also, stars that occur on the edges of the frame and the farther away from the pole will appear to trail more than others will. The best approach is to shoot a test exposure to determine the longest shutter speed you can use. Photo 4 Nikon D800, Nikon 14-24mm f/2.8 lens. Exposure for sky: f/2.8, ISO 1600, 30 seconds. On separate exposures, I Iight painted exterior of house with flashlight and interior with camera flash and yellow gel filter. Photo 5 Nikon D700, Nikon 17-35mm f/2.8 lens. Exposure for sky: f/4, ISO 1600, 30 seconds. Exposure for tent: f5.6, ISO 200, yellow gel filter on camera flash at half power. Aperture is a concern because of a lens aberration called coma. Ideally, you’d shoot with the widest aperture on the lens to allow in as much light in as possible. However, when shooting wide open, coma causes pinpoints of light at the edges of the frame to bloat and not record as points.