Shooting the Moon Again

The moon at 400mm
The moon at 400mm

Last night, I again tried to take a picture of the waning moon with the Canon 100-400mm IS lens I rented from Lens Rentals Canada. I used a tripod of course.

I decided to just try the full range of exposures to find what worked best. I set the ISO to 160 and the aperture to f/5.6 (the maximum for the lens at 400mm).

Based on the experiments from Friday, I started at 1/125s, and then moved down 1/200, 1/320, 1/400, 1/640, 1/1000, 1/2000, 1/4000 and 1/5000.

The first few were ok, but below 1/640, the moon started getting darker – not enough light was being captured.

The sweet spot seems to be 400mm, ISO 160, f/5.6 and about 1/200s. That was for a waning moon, just a little more than half-full. I wish that I had had more time on Thursday or Friday to try when it was nearly a full moon, but my schedule and clouds prevented it.

At 400mm, I can see the large craters along the terminator. This is what Galileo saw that lead him to realize that the moon was not a perfect celestial body, but rather one with an irregular surface – one more piece of evidence that the Earth was not the center of the universe surrounded by the perfect spheres of creation.

The smallest craters I can make out are 17 km in diameter. I can just make out the white dot representing the sunlit side of the Theon Junior crater. Not bad from 380,000km away.

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