Photo Tip 2: Shoot the Moon
Calculating the exposure for shooting the moon is easy. The moon is in direct sunlight so we can use the “Sunny 16 rule”. If you are not familiar with this rule of thumb, the digital equivalent goes like this: set camera’s time to one over the sensor’s speed and aperture to 16 using manual mode. Check this against what you in camera light meter suggest and you might be very surprised.
Here is an example.
Shutter Speed: 1/100
Aperture: F16
Sensor ISO Equiv: 100
Now it will be hard to hold a camera steady, especially with a telephoto lens on it and use such a slow shutter speed. We can make adjustments to the aperture and the ISO to increase the shutter speed while maintaining the same overall exposure value (EV). Link to article with detail exposure calculation information in it.
Same exposure (EV) as above.
Shutter Speed: 1/2000
Aperture: F8
Sensor ISO Equiv: 400
These two different exposures are the same. You may have wondered why your camera has the various values for the shutter speed, aperture, ISO. The reason is to make this type of calculation easy. One click of the aperture ring doubles or halves the light, one click of the shutter speed dial doubles or halves the light, and one level increase in the ISO doubles or halves the light. If you want more speed, you’ll have to increase the light (Aperture) or increase the light sensitivity (ISO). Each increase is roughly equivalent to 2 clicks on the Aperture and 2 levels on the ISO equals 4 clicks on the shutter speed. Cool ah.
Of course with life there are compromises and here is no different. Higher ISO means more grain (noise in digital terms) and with a wider aperture, the depth of field narrows. So watch out for the extremes of any of these settings.
Have fun with this and by using digital you can check your success in the field and bracket several exposures to ensure you capture what you envision. Just remember that the moon is in full sun even at night!
Today’s photography link is the fantastic “Astronomy Picture of the Day” sponsored by NASA. “The universe is really big and contains stuff. No really! I seen da pictures!”
It is snowing and I’m headed out to go snowshoeing on the mountain. I hope to come up with a good photo tip for you.
