Lunar eclipses are one of the Solar System’s most enigmatic events. The great thing about them is that there is no need for any optical equipment to fully appreciate them. Just look skyward and you can enjoy the moment that the Sun, Earth andd Moon perfectly align. One such eclipse of the Moon occurs on April 15th bringing a great opportunity to try and capture one of these events on camera.
Capturing any picture of the Moon on camera is actually surprisingly difficult. I have spoken to many people over the years who have seen a beautiful moonrise and tried to capture it only to be disappointed with the result; the Moon is invariably too small and usually over exposed.
The trick to getting good lunar shots during eclipses or not lies in increasing the focal length of the lens. For satisfactorily large image scale I will only ever shoot the Moon with at least 200mm lens for scenic shots or for really closeup images of the full lunar disk then I use a 300mm lens with a x2 converter so I am working at about 600mm. Getting the exposure right is also somewhat challenging and usually the problem stems from the small size of the Moon in the frame. A camera will calculate exposure based on the entire scene so with a small image of the Moon, it will expose for a darker scene leaving the Moon far too bright. Increasing the size of the Moon in the frame means the camera has a better chance of getting the exposure right.
Lunar eclipses increase the challenge a little more because the brightness of the Moon varies significantly from the early stages to the moment of full totality. It is best to set the camera to manual mode if you have one, then set the ISO setting to about 100, followed by an f/ratio of f/8 and then experiment with the exposure settings. For an un-eclipsed Moon then try an exposure of about 1/250th of a second but do not be afraid to experiment if it is not quite right. Then as the eclipse progresses, slowly increase the exposure time. If the eclipse is particularly dark then you may need to increase the ISO setting as it progresses so do not be afraid to try different settings.
If you want to learn more about the causes of lunar eclipses and the details of this one in particular then you can learn more in my article In the March edition of Science Uncovered. There is a great opportunity for a FREE trial subscription for 3 issues right here.