Kelvin Hennesy's Moon

1 November 2019

This remarkable photo was published on the Australian Amateur Astrophotography Facebook page by Kelvin Hennessy. It’s a group of climbers on the Q1 building in Surfers Paradise with the full moon behind them.

I had to ask Kelvin how he took it.

Kelvin told me that he was inspired by Luke Taylor’s videos of the full moon rising behind the Cape Byron Lighthouse. He wanted to try has own version using the top of the Q1 building as a target.

The telescope he used was a saxon 127mm FCD100. This is a triplet refractor which is normally used for astronomical work, as it has virtually no chromatic aberration. For Melbourne residents we have one in our showroom if you want to see it.

I was surprised at the mount Kelvin used – it’s a saxon AZ3. You can see it in the photo that Kelvin sent me (and which I’ve brightened heavily). Kelvin says the mount works fine as long as it isn’t windy!

I asked Kelvin how he planned the photo.

For initial planning, he uses Photographer’s Ephemeris, a website that shows the direction of the moonrise superimposed on a satellite map. He then fine-tunes the location using Photopills (an iPad app), as well as Google Street view, which shows if the building is actually visible from the location.

It took Kelvin many months and several failed attempts just to get the location correct for the moon alignment. His next problem was to get a photo where there were climbers present. He had to look up the schedule of the SkyPoint climbs and factor in how long it takes the climbers to get to the top of the platform and how long they normally remain up there.

I was also interested in lighting on the front of the building. For this, timing between sunset and moonrise was critical. If moonrise was too late the building became a silhouette. Too early and the Moon was too pale. For the optimal shot, the sun was fully set 4 minutes after the moon appeared behind the climbers.

I’m knocked out by the planning, the equipment and the photo. Amazing, Kelvin!