Photographing A Total Lunar Eclipse
May 15, 2003
There's a full moon every month. If the Moon's orbit wasn't inclined 5 degrees we would also have a lunar eclipse every month. But it is, so we don't. Consequently lunar eclipses are rare.
A lunar eclipse happens when the moon passes into the shadow of the earth. This makes the moon grow dark, and only sunlight filtered though our atmosphere reaches the moon and illuminates it with a ruddy crimson glow. It is a strikingly beautiful sight. The last time I saw one was in 1989 and I still remember it vividly.
The next lunar eclipse will take place on May 15th, 2003. It will be visible throughout North and South America as well as extreme Western Europe. In North America it will occur not long after sunset on the west coast, around midnight on the east coast, and at sunrise in the U. K. and western Europe.
A Lunar Eclipse in Three Exposures
Credit & Copyright: Stephen Barnes
Used with permission
From the point of view of the casual observer or amateur astronomer the whole night is available, and regardless of where you live as long as you have clear skies you should have a wonderful experience. But likely the best photographic opportunities for landscape photographers will occur in the desert areas of the western U.S. The reason for this is twofold. First, the desert has the highest likelihood of clear skies that day, and secondly, the western quarter of the continent will have the eclipsed moon rising shortly after sunset. (Folks in the U. K., and other countries in western Europe will have a great opportunity to shoot the eclipsed moon setting at sunrise on the 16th — if they have clear skies). Whether at dawn or dusk, for the landscape photographer the moon low in the sky while eclipsed will be sensational.
Photographing The Rising Moon
Photographed with a Rollei 6008 and 300mm Schneider Apo-Tele-Xenar
On Fuji Provia 100
I took this photograph in Death Valley in the Fall of 1999. The full moon was rising shortly after sunset, just as it will on May 15th, 2003. But this time it will be in eclipse as it rises and it could make for some extraordinary photographic possibilities.
One thing to remember is that the moon, like the earth, gets its illumination from the sun, and therefore since it is gray needs an exposure pretty much the same as a sunlight scene on earth. The Sunny 16 rule; 1 / ISO @ f/16 — but with about 1 stop + compensation because you want it to appear light gray not medium gray. When its closer to the horizon though, and the light has to pass though more dirty air, it is one to two stops dimmer. There are a lot of variables. For this reason bracketing is well worthwhile, and if you're shooting digital check your LCD and histograms often. And of course while in eclipse it will be much dimmer, making it possible to shoot it much longer after sunset without it burning out.
You need to keep this in mind when shooting the full moon at sunrise or sunset. If the dynamic range between the moon and the surrounding sky and foreground is too great then you'll either burn out the moon or underexpose the foreground. But the cardinal sin of doing this sort of photography is burning out the moon. You need to hold detail there and let the sky and foreground fall where they may, as seen below.
Canon EOS 1Ds with 300mm f/2.8L and 1.4X @ ISO 250
For this reason there is just a narrow band of time when the moon and the sky and the foreground are in balance. Be aware that with a long lens there is the potential for problems with the moon moving during exposure. This normally isn't a problem but since the moon will be quite dark during totality be sure to keep the exposure shorter than about 1/30 second. This may require ISO 400 or 800, so be prepared.
Since this article first appeared a couple of readers have pointed me to a page with a free Astrophotography Calculator (Windows only). I highly recommend this program as it will allow you to calculate a starting point for your exposures for this as well as other events.
I was a bit surprised at the results and they have caused me to rethink my plans. For example, I am planning on using a 500mm f/4 lens to photograph the landscape and eclipse. The program shows that if I use ISO 800 and the moon at totality is relatively light (which is the forecast) then I will need an exposure of about .5 seconds. This is just fast enough to avoid blurring due to moon motion with a 500mm lens. ISO 800 is faster than I would like to use, but appears to be what's needed.
One of the critical things that you will need to know in preparing to photograph the eclipse, especially from the West Coast where you'll want to be able to shoot it as it rises in eclipse, is — exactly where is it going to rise? For example, from Death Valley it will be at 123 degrees east of north. But, if you're using a compass, the magnetic declination is about 13 degrees so a reading of about 109 degrees will be needed. (I know it's complicted, but this is what it takes to get it right).
There are a large number of programs available for all computer platforms, including PDAs. Bill Arnett publishes a very comprehensive list of freeware, shareware and commercial programs for all platforms, where you will be able to find something that meets your needs and budget. Bill recommends Starry Night.
Where to Shoot
May 15th is a Thursday. For most people the choice of where to shoot the moon in eclipse that day will be determined by personal factors, like jobs and family obligations. But, if you have the time, and means, and the desire, where out west and what kind of foreground subject would you want to shoot this remarkable event? I gave this some thought and came to the conclusion that the desert and mountains of California and Nevada would be best. As mentioned above, the desert has the best chance of clear skies. Also, the clear air and long vistas will allow using something like sand dunes or a mountain range as foreground.
In Death Valley, for example (not far from Las Vegas — a convenient place to fly into) sunset that day is at 7:40pm. Moonrise is just minutes before at 7:32pm, and the moon will already be in partial eclipse as it rises. By the time of greatest eclipse, at 8:40pm, the sky will be too dark. But in the time between sunset and moonrise, and an hour later, there will be terrific photographic opportunities. At about 8pm the moon will be 4 degrees above the horizon, and by 8:30pm it will be 9 degrees. Somewhere in between, depending on altitude and how high any mountains in the foreground might be, the moon will be at its best. As noted, these times are for Death Valley and will vary depending on where you may be. A check of a good almanac will provide local data for where you might find yourself on May 15th.
What Lens to Use
This largely depends on where you'll be shooting and what the foreground might be like. My 1999 Death Valley shot above was taken with a 300mm lens in 120 format. This is the same as a 150mm lens on 35mm. The Quebec moonrise above was done at the equivalent of 420mm. It takes about a 1,200 millimeter lens to fill the frame. Somewhere in there is your best bet. Too wide and the moon will be unimpressive. Too large and it will look like a shot from Sky and Telescope magazine. I expect to use either a 400mm or 500mm lens that night.
I am planning a workshop for Death Valley that week specifically to shoot the eclipse. The probability of clear skies there is very high, and the open vistas lend themselves to the kind of set-up that I think will work best. In addition to the eclipse this workshop will also spend 4 days shooting in and around the remarkable locations found in Death Valley.
If you can't make it on this workshop, do try and find a spot somewhere to view and photograph this lunar eclipse. If you get a good shot, let me know. I might publish it here as a follow-up to this article.