Photographing the moon -- a tutorial

Here's a shot of the nearly full moon at twilight taken a couple of days ago, on February 12th. Every now and then I post a photo of the moon here on the blog, and when I read the comments there's always someone who says they wish they knew how to get a good moon shot. I think people don't realize how bright the moon actually is, and that's why they fail to get a decent shot of it. I'll try and explain here how to do it with better success.

First of all, it's important to understand that the moon is very bright. Day or night, have you ever noticed that the moon is always exactly the same luminance? Even if the sky is completely dark, the moon is as bright as it always is, and that never, ever changes. If you don't believe me, just go outstide tonight and stare at it for a few seconds, and you'll notice that it's burning your retinas! So to get a good exposure of the moon with all its detail intact, your exposure for it would be the same as if you're taking a picture in broad daylight, even if you're actually doing it in the dark of night.

The other thing you'll need to understand is that everything else in the picture (in other words, the landscape) is probably an ENTIRELY different exposure value than the moon. This creates a problem:  if you expose correctly for the moon in all its brightness, chances are the rest of your photo will be vastly underexposed. If you expose for the rest of the stuff in the picture (much darker than the moon), the moon will be vastly overexposed.  In fact, it's practically impossible to get a good nighttime shot of the moon and the landscape together. The solution is to take two different exposures. What I'm basically trying to explain is, the photo above is actually TWO pictures put together: one photo in which I exposed solely for the landscape (the trees in the foreground), and a second photo in which I exposed solely for the moon. If you want to try this, you'll need a camera that will allow you to shoot in manual mode. A tripod, while not strictly necessary, will help you keep the framing consistent with the different shots you're going to take. Also, it goes without saying that a long lens (I used a 200mm here) would be helpful. And finally, you need to have some basic Photoshop skills to do the editing.

Take a look at the images below. In picture #1, the trees are in focus and are perfectly exposed. The sky is too bright, however, and the moon is blurry and completely blown out with almost no detail. In picture #2, I've exposed for and focused on the moon (and you can see all its lovely detail), but the trees are completely black and out of focus. That's how vast the difference is, exposure/lighting-wise, between the moon and the landscape. If you scroll up to the picture at the top of this post, you'll recognize those nice, sharp, perfectly exposed trees from picture #1, and that nice, sharp, full-of-detail moon from picture #2. I used picture #1 as my "base" photo, photoshopped out the blurry moon, then simply lassoed and dragged ONLY the moon from picture #2 onto the space where the blurry moon had been on picture #1. Also, since the sky in picture #1 was too bright, I fiddled with the blue channel to make it darker and give it the right amount of saturation to match the sky in picture #2, because I preferred the darker sky. In the finished picture, I enlarged the moon just a tiny amount, maybe 2-3%. Of course you could probably make the moon unrealistically huge and everyone will say "wow!", but I prefer things to look as natural as possible -- that's just my style!

That's it! In the "old days", this would have required a lot of expertise and know-how in the darkroom -- what we used to call dodging and burning. In Photoshop it's a little easier and a lot less sloppy ;^)

A final note:  if you want to take a picture of ONLY the moon with no landscape, just remember that it's as bright as daylight, no matter how dark the sky is. Expose for the moon's bright surface. You won't need to take a second exposure for the night sky, because if you expose correctly for the moon's bright surface, the sky should go a nice deep black in your shot.

If you have any questions, just leave them for me in the comments section and I'll do my best to answer them quickly!