If you’re in a hurry you can ignore the discussion and skip straight to the summary
Back in the olden days, when cameras were carved out of stone and didn’t have whizbang light meters and dozens of confusing exposure dials, photographers had to choose their settings manually. In fact, my first 35mm camera, a Kodak Pony IV, had printed inserts that went into a slot in the back of the camera to help you pick your settings. For bright sunlight you used this, for cloudy bright you used that, etc. And horror of horrors, there was no Photoshop– if you screwed up the exposure, you had to try to fix it in a (gasp) darkroom. And that was if you were lucky– most people just lived with whatever bad photos they took.
Back in these dark, dark days, photographers often relied on rules of thumb to help them choose their exposures. The most common of these was called the Sunny f/16 Rule. The rule went like this: for objects that are brightly lit by the sun, set your aperture to f/16. Set your shutter speed to 1/ISO of the film. (Film? Do you remember that?) So if you were shooting with ISO 100 film, you’d set the camera to f/16 and 1/100 sec, or as close to that as you could get. At ISO 200, it was f/16 and 1/200 sec.
I know what you’re thinking. That’s great, Patti. Thanks for your little stroll down memory lane, but someone has been spiking your Geritol. I want to photograph the moon, and I want to do it at night when it’s dark out. Why would I care about sunny days?
Here’s a little secret. The moon is nothing more than a bright object lit by the sun. Sure, it’s in a dark sky and everything around you is dark, but the moon is surprisingly bright. However, it’s also pretty far away, and that makes it look pretty small in the sky and even smaller through your camera’s lens. Unless you have a very long telephoto lens, your camera’s meter just won’t know what to do with the shot. If you’ve tried to take a picture of the moon in automatic mode, you probably got a small white dot on a dark but washed-out background. We can fix that, but it will mean putting your camera in manual mode. I hope that’s not as scary to you as it would have been before you started reading this blog.
Let’s go back to that telephoto lens thing for a moment. The first thing you want is the longest telephoto lens you can get, so that the moon looks like something other than a white dot. 200mm is about the shortest, 300mm is better, and 500+ is even better than that. If you don’t have a long lens, a teleconverter is a useful accessory to have. In a nutshell, a teleconverter is kind of like a magnifying glass added to your lens. With a 1.4x teleconverter, a 200mm lens acts like a 280mm lens, and with a 2x teleconverter, a 200mm lens acts like a 400mm lens. There are some serious downsides to using teleconverters, but they can also be useful tools.
[Update: I've recently added an article titled What lens should I use to take a picture of the moon? It has examples of moon shots at focal lengths from 200mm to 2240mm.]
First off, use manual focus. Because the moon is pretty small in your viewfinder, many cameras have trouble focusing on it. If yours works in autofocus that’s great, but if not just switch to manual focus and do it the old-fashioned way.
In my experience, the Sunny 16 Rule is close but not quite right for the moon. The best settings I’ve found seem to be around ISO 100, f/11, and 1/100 sec. However, sometimes something a little slower or faster does a better job. Because of this, I recommend doing something called bracketing. Bracketing is just a fancy term for taking a bunch of shots at slightly different exposures so that you can pick out the best one.
Set your camera for manual mode, ISO 100, f/11, and 1/100 of a second. Take a picture. Now without changing any other settings, set the shutter speed to 1/200 and take another picture. Do the same thing at 1/400. When you’ve done those three, go the other way. Set the shutter speed to 1/50 and take a picture, then 1/25. If you aren’t using a tripod, don’t forget to brace the camera against something solid like a wall or a pole, so you don’t get camera shake. And voila! One of those is probably a pretty good shot of the moon.
- Manual mode, at f/11 and ISO 100
- Focus manually
- Use a tripod or stabilize your camera against a sturdy object like a wall
- Start at 1/100 sec and take a shot
- Bracket a couple of shutter speeds faster and slower (e.g., 1/60, 1/30, 1/200, 1/400, or whatever speeds are closest to those on your camera)
- Look at the images on your computer and pick out the best one
The next time you have a clear, dry night and the moon is in the sky, try it yourself.
And here are a few products that may be useful in shooting the moon:
The Tamron pro series of teleconverters are optically quite excellent. Their physical geometry makes them work with most telephoto lenses (at least on Canon… I’m less familiar with Nikons), and they give you a fair bit of extra focal length to bring the shot in closer.
This little gizmo is amazing. It lives on the strap of your camera, completely out of your way, but just waiting until you need it. When you do, pop it off and voila– you have a wireless infrared remote. It works with most Canon dSLRs, it’s inexpensive, and it’s incredibly useful.