As was well noted by the media, January 20-21, 2019 presented a total lunar eclipse, visible in the Western hemisphere. So, what’s the deal? Why am I only talking about a partial eclipse? Let me explain. When the opportunity to photograph this astronomical event arose I did research. Lots of it. How do you focus on the moon? How does the exposure change as the eclipse progresses? What equipment is needed for the best result? Can you hand-hold the camera for a good exposure of the moon? Lots of information, some very helpful, is available on the internet. I had my ideal images in mind, and had scouted out the location I hoped to go to. Then things changed–like a very unfavorable weather forecast. Snow. Single digits. Wind. And the AFC Championship game between the Patriots and KC Chiefs. What else could go wrong?
Let’s begin by comparing these two photos.
The image on the right is more recent. It was taken with my Nikon D850 full-frame DSLR using the Nikkon 300mm f/4 PF lens and a 1.4x teleconverter. The image on the left is from the partial phase of the eclipse. This was taken with my Nikon D500 crop-sensor DSLR, using the same 300mm lens, but no teleconverter. Both images are cropped and using a tripod. So, if I could get this image of the eclipse in a partial phase, why not the total eclipse?
The light from a full moon is essentially the same as a landscape during daylight. That is, you could start testing exposure using the Sunny 16 Rule. However, a much longer shutter speed is needed during totality, when you can see the stars along with the moon.
Well, after the football game I decided to see if the weather had cleared. Indeed, it had! Hardly a cloud in the sky–or a degree on the thermometer. So, I bundled up carefully and ventured into the back yard to give it a try. What follows is here as a lesson of what can go wrong, even when you do the research and prepare.
I knew the moon would be at a high elevation–over 80 degrees above the horizon. But, it did not register in my aging brain that the moon would therefore be nearly overhead. That means the camera must point directly up. Try that with a camera on a tripod! Then try to see if you have the moon in focus. Clearly, I did get one image in focus, the one of the partial eclipse above.
Further, I had intended to modify my schedule for changing the exposure so that I didn’t have any shutter speeds faster than 1 second. With the lens and camera I was using, the 600 Rule for astrophotography called for an exposure no longer than 1.3 seconds (600/450, the full-frame equivalent) . I had not done this, however, because of the ominous weather forecast. So, I ended up going with the exposures on my carefully planned sheet–8 seconds during totality. Way too long to avoid motion blur. My cold brain didn’t think to move my frigid fingers to make the adjustments necessary. The result is above. Lesson learned–but no chance for redemption until at least 2020.