Not Eclipsed!

I was crestfallen to see the weather reports. The last total eclipse of the moon visible from North America until 2014… and the weather everywhere within a reasonable 3-4 hour drive was predicted to be 90% clouds and worse. It seemed my eclipse was going to be eclipsed by cloud cover.

At about 9:15 PM, PST, however, I looked up and saw… THE MOON!  Sure, it was scintillating in a little sucker hole playing with me. But I decided to play along. I hastily hauled out the Canon 5D Mark II, the 70-200mm f/4 IS L lens, the 1.4x Telextender, and the Gitzo carbon fiber tripod. Why those? Because that’s what I found first.

My equipment was scattered about in my office still recovering from the wet weather we have had here in San Jose. Indeed, I did not find the batteries for my Canon 50D camera.

Photo 1: A Hole in the Sky

By the time I got set up, I realized that the moon would very soon be contacting the earth’s umbra (darkest part of the shadow). So I quickly got to shooting what I could. Never mind that it was cold and I was not dressed properly.  Soon enough the clouds would come and I could dart into the house to hurriedly collect what I was missing.  The first shot I got was with the moon in the earth’s penumbra (Photo 2).

Photo 2: Moon in Earth's Penumbra

Through various breaks in the clouds I was able to get photos from first umbra contact all the way up to totality. Including a serendipitous shot of an airplane headed, probably, to the San Francisco airport or some other place to the north west.

Photo 3: Airplane transits the partially eclipsed moon.

What settings did I use for these shots? f/7.1, ISO 200, and 1/400 of a second exposures. Why so fast? Because, my friends, the moon is BRIGHT. Even partially eclipsed, even already in earths penumbra it is a big bright object. Shooting the moon is a definitive case where your camera absolutely cannot get the right exposure if left to itself. A good exposure must be manually set. I arrived at my settings by a few quick trials. I started at about 1/200th at f/5.6 and noticed that I was getting some over exposed areas (on my LCD screen the overexposed pixels blink white). I then decreased the aperture and continued to tweak the focus.

I wanted the moon images to be as well exposed as possible – especially knowing that the thin clouds were going to dim the image. My goal was to get detail in the moon, I did not care about the clouds or stars. In fact it is impossible – except at a very slender crescent or during a total eclipse to get detail in the moon AND also show stars in the sky. Why? Because the moon is so, SO bright.

I definitely made a slew of mistakes. The most significant one is that I should have put the telephoto lens on my 50D body which is a 1.6 crop camera. Had I done that all my moon images would have been about twice the size of what I actually got. Not having my camera all packed away in my bag meant some lost opportunities here.

I also thought  that perhaps the 5D would have been a good choice to get a sequence of shots showing the progression of the eclipse. The idea was to get the moon in the bottom corner of the frame and take a series of shots as it moved to the upper left of the frame. This also did not work for several reasons. The first problem was that the cloud “holes” came at irregular intervals – so spreading them across the frame evenly was not going to happen. The second problem was purely my failure to correctly guess the path the moon would follow in the sky.  Had I been a little smarter I’d have switched lenses when I realized the timelapse path was not going to work. But instead I tried again a few times.  I also realized that when the eclipse was total, the moon was going to be quite dim and the superior high ISO performance of the 5D II was needed. For the totally eclipsed shot, the ISO was ramped all the way up to 1600 and the exposure dropped from 1/400 to 1/6 of a second. That is a HUGE difference. The slower exposure meant that details in the moon would be blurred and the stars at this telephoto range would become dashes rather than dots.

Photo 4: Nearly Total - With enough bright area left to form a halo in the clouds

All in all, I guess I’ll be better prepared for 2014 when the next total lunar eclipse is visible from North America.

2 thoughts on “Not Eclipsed!

  1. Adarsha

    Excellent article Steven. and beautiful shots!!
    I completely understand when you mentioned about thin clouds causing the problem. This year two months ago, Moon was supposed to appear biggest in last few year, I tried to capture it. But even after driving few hours to get a good look, it was either complete cloud cover or thin clouds. All I could capture was a big blob of light..

    1. Steven Christenson

      Adarsha, You might want to read my article “Alignment Part 2” where I describe the proper settings for capturing moon detail. If you’re getting a big white blob you’ve either allowed your camera to select the settings which never works** or were fooled by your histogram.

      **Like all generalizations never is not correct, however the moon is a tiny and bright. If you use enough magnification to fill your frame, your camera may get the exposure correct on its own, but you’ll need a focal length of about 8000 mm.


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