While I’ve always enjoyed seeing the moon turn red during an eclipse, I’ve honestly never made any attempt to capture it in an image. This time I decided to try something out, but I also wanted the image to appear like my own, something that would work with my personal style. The prairie was an obvious choice and I knew of a homestead that faced in the correct direction to make it work. Seeing how I shoot on film, I also wanted to get it right on just one sheet and not a composite. A multiple-exposure image of the eclipse progressing across the sky would be perfect for this spot!
When I posted the image on Instagram, there were immediately a ton of questions about how to pull off such an image. This final image has 21 exposures on one sheet of film, and most of the questions seem to revolve around how I managed not to overexpose the sheet. It’s actually quite simple, but my goal is to clear out some of the confusion around multiple exposures with this blog post.
The Twilight Exposure
First off, I had to make an exposure for twilight. There was just a bit of subtle sunset color in the sky which worked well for me. I used a 210mm lens and shot a slightly underexposed exposure on the sheet of film. Not all that underexposed, but the goal was to make sure that the moon would be highly visible later on. For this scene I decided to use Kodak E100 for a few reasons. Slide films generally perform quite well at night and show true colors, and E100 is very forgiving with exposure (for a slide) just in case I messed something up. The twilight exposure was about 3 seconds at f22, with a 1 stop soft GND over the sky and an 812 filter to remove some of the green cast of E100. Had I not shot the moon on the same sheet the twilight exposure would have looked like this:
At this point I photographed the ground glass with my cell phone camera so I could have a reference for the moon. The moon was actually just rising during the twilight exposure, but ever-so-slightly out of frame on the 210mm lens. This was intentional, a 210mm lens allowed me to stand back from the homestead and also made the tree relatively small in the frame, but it wouldn’t give me as much room for the long arc of the lunar eclipse. For the eclipse I wanted to use a 135mm lens, so I switched out lenses and moved the camera about 100 feet so that I had a clear view of the horizon. There was no need to have the homestead there anymore, the rest of the images would be so dark it wouldn’t show up anyway.
Setting up for the Moon
Using my cell phone image as a reference, I then placed the moon in the appropriate spot in the ground glass knowing that it would travel across the sky in an arc. I used an app that shows moon location over time to make a rough guess, but that app had no way of comparing it to a particular focal length. To be honest, I was a bit in the dark during this stage. My goal at this point was to just choose an exposure interval and stick with it, following the moon until it had traveled most of the way across the frame. This was also a guess, as there was no way for me to look through the ground glass once I started the multiple exposure process. Wiggling the film holder was too risky!
I settled on 8 minutes in between each exposure, deciding that the roughly 3 hour event would look good in about 20 frames. Again, this was some guesswork. All that really mattered was consistency, so I set a timer for 8 minutes between each shot of the moon. To begin the process, I gave the camera a good wiggle to make sure it was on solid ground, pulled out the darkslide and took my first shot of the eclipse. I would then shoot again every 8 minutes.
Multiple Exposures
Let’s rewind just a little bit. By far the most frequent question I’m getting is how I managed not to overexpose the sheet of film. Quite simply, when an image is appropriately exposed for the moon at night, the landscape is so dark that it does not show up on the film whatsoever. This is because the moon is bathing in direct sunlight and is many dozens of times brighter than the earth in full shadow. A proper full moon exposure is roughly the same as shooting a bright desert scene in full sunlight, taking just a tiny fraction of a second. Shooting a night landscape takes hours to expose properly, a short burst of an exposure will not reveal the landscape at all. Keep in mind that the moon moves across the sky, so it will not overlap if you wait a few minutes between each exposure. This image below shows what each of the moon exposures would have added to the frame:
As you can see, this would make no difference at all to the previous twilight exposure on the sheet of film. No matter how many short exposures I shoot, it would never reveal the landscape below.
Proper Moon Exposure
The moon changes brightness significantly during the lunar eclipse. From the beginning, it’s not quite as bright as a normal full moon as it starts to work its way into the softer, outer portion of earth’s shadow during the penumbra stage. It will then darken again as the earth’s shadow starts to take a bite out of the moon and finally will become many times darker as the full eclipse starts and it becomes the so-called “blood moon.” The best way to ensure proper exposure is to actually meter the moon.
I had my small light-meter m43 camera set up on a tripod in manual mode, pointed at the moon so I could make exposures and judge the brightness. Mostly I was looking for detail and reasonable brightness in these preview digital exposures. The first and last few exposures were only 1/30th at f11, but it got much darker during the total eclipse. All of the red moon exposures were about 8 seconds at f5.6 - wide open for the lens. I didn’t want to go any longer or the moon would start to travel across the exposure and appear oblong. I carefully cocked the shutter and set the aperture (without wiggling the camera) after making my meter reading and then took the exposure when my timer hit 8 minutes.
After about 3 hours, the moon had moved far enough up and to the right that I had a feeling it would have been in a good spot to finish. This was just an eyeball guess standing behind the camera and comparing to where it was when I started. I put the darkslide back in and pulled out the film holder. Finally I was able to look through the ground glass and the moon was exactly where I hoped it would be! I took down the camera and found a place to camp on the prairie. After staying up much later than usual for me, I was sound asleep in minutes.
The final image on film. Prints available.
This method is actually a really old-school way of capturing the lunar eclipse, but has mostly been forgotten in our digital world. I highly recommend that you check out Mr Eclipse (Fred Espenak) if you want to learn way too much about photographing the eclipse in a variety of ways. He has a lot of exposures on film and definitely provided some confidence as I set out to capture this event. That website has endless knowledge on eclipses in general too.
This image is also available as a print here if you’d like to hang this one on your wall.