The Sunny 16 and Moony 11 rules

I remember my photographer teacher talking about the ‘Sunny 16 Rule’ when I was shooting an old Canon A1. It’s one of those pieces of information you kind of forgot when you make the move to the digital world, where automation rules, and manual exposure tricks are resigned to becoming problem solving tricks. Why remember tricks when matrix metering is so smart?

Well, recently I was asked about taking pictures of the moon, which is when that buried information struck me again. Because of the way a DSLR meter measures light, by trying its best to find a balance of light and dark, you’ll find it’s difficult (even with a spot meter) to properly expose something like the moon. The ‘Sunny 16 Rule’, or more appropriate to this particular question, the ‘Moony 11 Rule’ – is perfect for this type of problem.

The Sunny 16 Rule

The Sunny 16 Rule goes like this. If in bright sunny conditions, if you set the aperture to f/16 and your shutter speed to the ISO you’re shooting at, you’ll get a proper exposure. So, if you’re ISO is at 200, set your camera to shoot f/16 @ 1/200sec.

If the scene is slightly overcast, you can modify the Sunny 16 Rule by opening the aperture to f/11. Heavily overcast, set it to f/8… and so on, depending on the level of light you’ve got.

The Moony 11 Rule

The Moony 11 Rule is useful for taking pictures of the moon. Because the moon reflects sunlight, it’s a similar exposure situation as a slightly overcast day. The rule works the same way. Set your aperture to f/11 and your shutter speed to the ISO of the camera.

Because the lighting won’t always fall squarely into these exposure rules, some tweaking may be required – but they’ll definitely get you in the neighborhood.