So I’ve gotten a lot of positive response to the star trails article, although curiously not in the Comments Section!! Aside from asking about details about star trails photography, the most common question has been: “how do you take photos of the stars”?
Title: Trinity Stars
Info: Nikon D7000, Tokina 11-16mm f/2.8 lens, Dorcy LED flashlight for “light painting” the rocks and the trees. 30 second exposure, f/4, ISO 500.
Photographer: Ken Lee
Location: Joshua Tree National Park, CA USA
FOCUSING AT NIGHT: First, we’ll discuss focusing. That’s the hardest part of night photography, so I’ll start off with this and scare off the timid. 😀
There’s going to be some variability depending on the camera and lens you use, so it’s not just a simple matter of saying, “Do this, then do that.”
I focus on the stars by setting my lens to “infinity”. But wait….it may not be quite as easy as that. Why? Because not all lens indicate “infinity” in the same manner. The easiest way to do this is to go out some time when there’s some daylight and focus on something extremely far away, like some mountains or the clouds or something and see where your lens perceives “infinity” to be. It may be right at the lens’ Infinity marking. Or slightly to the right. Or slightly to the left. With one photographer’s Pentax lens, it was between 11-14 ft.!!! Now, I’m rather lucky because the “infinity” setting on my Tokina 11-16mm is right in the MIDDLE of the infinity symbol. Beautiful. Regardless of where it is, mark that setting.
Title: The Guardian of Forever
Info: Nikon D7000, Tokina 11-16mm f/2.8 lens, Feisol tripod. Exposure time 25 seconds at f/8, ISO 200. Light painted with flashlight and red headlamp. That is the moon peaking through the middle of the arch!
Photographer: Ken Lee
Location: Arch Rock, Joshua Tree National Park, California, USA.
If you are shooting at night and haven’t tested for infinity yet, try and focus on the shots as best you can, setting it to where you believe infinity is based on the markings on your lens or, if you can, manually.. Then take test photos of the stars and view ’em in your LED, zooming in on the stars. Then adjust your lens accordingly, zeroing in on where the stars look the sharpest. This may take a while. Be patient. You want the stars to be as sharp as possible. It looks great. After the first time you do this, it gets much faster and easier. Using a flashlight, or better yet, a small headlamp with red light so you don’t constantly zap your eyeballs with white light, is the easiest way to view your lens and camera settings.
When you find your focus, switch your lens and camera off “auto focus” and on to “manual” so it won’t get moved again. This is your infinity focus that you’re going to use from now on. Some people use gaffer’s tape or blue painters’ tape to hold the lens in place, a good idea I picked up from Dennis Mammana, a night photographer.
If you can nail focusing at night, everything else is comparatively easy.
EXPOSURE: Since you want the stars to be pinpoints, you need a relatively short exposure…at least, by night sky photography standards. And that means keeping it under 20-30 seconds, depending on what lens you have. A wide angle lens tends to show trails less than a telephoto lens. I’ll let you figure out why. 😀 Much longer than 30 seconds, and your photo will likely show your stars as a very short line and not a pinpoint of light.
Use a lens at a fairly wide aperture, something like f/2.8 is nice. Something that is good and wide to let as much light in as possible since stars don’t give off all that much light. You can set it to smaller apertures but then you won’t let in as much light, and you’ll have to kick up your ISO.
Title: Hidden Valley Nights
Geek Stuff: Nikon D90 with Tokina 11-16mm f/2.8 lens, Feisol tripod; 30-second exposure, f/2.8, ISO 800. 26 March 2012. Everything is lit solely by moonlight.
Photographer: Ken Lee
Location: Hidden Valley, Joshua Tree National Park, California, USA
Now, set your camera to the lowest ISO you can get away with while still having your stars show nice and bright. Why the lowest ISO you can get away with? Because higher ISOs, while more light sensitive, also introduces more noise.
On my camera/lens combination, my widest aperture was f/2.8, good and wide, and with that wide of an aperture, I could get away with an ISO as low as ISO 800 for a 30-second exposure, which is quite good. ISO 800 on a relatively modern digital camera doesn’t introduce too much noise. If I wanted, I could have probably used a higher ISO such as 1600 if I wanted a 20-second exposure, which would have had less star trails, but I was satisfied with the lack of star trails on my 30-second exposure and chose to keep those settings.
If your image is too dark, make it brighter. Widen the aperture. Kick up the ISO. Or if you must, lengthen the exposure time, but remember that past 30 seconds, the stars may start to appear as very short lines, although I’ve seen people do exposures of 40 seconds that still looked like pinpoints because the used an extremely wide angle lens or just managed to get away with it somehow.
If your image is too bright, make it darker. That’s easy. Lower the ISO. Make your aperture smaller.
Exposure is fairly simple. Darken or brighten using the same tools you do during the day. Focusing is a greater challenge, but if you’re patient and take some test shots, you’ll nail those too.