On Saturday, I couldn’t help but go outside and watch the “supermoon” for a while. For those who don’t know, supermoon has become the fashionable term to refer to a full moon that coincides with the closest approach the moon makes to Earth in its orbit (also called the moon’s perigee). Saturday’s supermoon was about 30 percent brighter than the average full moon, and as I stood outside my apartment building at around 10pm, the light from the moon seemed to overwhelm the LA streetlights.
I figured this would be a good opportunity to get some images of the moon’s disk, so I brought out my camera and my biggest telephoto lens, a 500mm. As many photographers know, you can use a modern SLR’s “live view” function to help you manually focus on small or distant objects; by magnifying the sensor’s image, on the camera’s LCD screen, you can see minute details and focus more precisely than you can by looking through the viewfinder.
As it turns out, this is a pretty cool way to see some amazing details on the Moon, too! With a decent telephoto lens and magnified Live View, your camera isn’t half-bad as a telescope. My wife Liz was looking at the highly-magnified moon image on my camera’s LCD screen, and she asked “why does it keep moving?” I wasn’t sure what she meant at first; it’s hard to keep the camera steady at extreme magnification levels, but the motion Liz noticed was smooth and consistent. We both realized at the same time what we were seeing: the moon’s apparent motion across the night sky! We were seeing the Moon with so much magnification that we could actually watch it “move” as the Earth rotated beneath it! Pretty darn cool, if you ask me!
Here’s how you can observe this effect yourself:
- Attach your camera and your longest telephoto lens (mine was a 500mm + 1.4x teleconverter, but a shorter combination should also work) to a sturdy tripod.
- Aim at the moon, focus through the viewfinder, and lock down the tripod.
- Switch to Manual exposure mode to maximize your control over the Live View image. If your camera allows “exposure simulation” in Live View mode, that’s the option you want.
- Activate Live View and adjust your aperture and shutter speed settings to get an image of the moon on your screen that’s not overexposed.
- Zoom in as far as you can on the Live View image. Fine-tune your focus on the moon.
- If your lens has Image Stabilization / Vibration Reduction, turn it OFF. By attempting to correct for random camera movement, your lens’s IS will obscure the subtle movement of the moon.
- Enjoy watching the moon move across your LCD screen!
Let us know if you try this for yourself. How did it work? (You don’t need a supermoon to make this work — try it out on any moon, any phase, super- or not-so-super!)