APY Masterclass - Capturing Venus and the Moon

Lighting Venus's crescent and the lunar limb evenly is no small feat

Ever since I first became interested in astronomy, I have been fascinated by the iconic images of Earth rising above the lunar horizon from the Apollo missions. When I realised that the Moon's occultation of Venus, visible on 19 June 2020, would give me the opportunity to capture a similar image for myself, it immediately became one of my astrophotography aims of that year. I decided to capture the event with a very narrow field of view in order to enhance the 'crescent over lunar horizon' feeling and I also wanted to capture the event in colour to record the daylight blue sky. To achieve this, I used my Celestron C11 equipped with a colour planetary camera at prime focus.

In order to achieve a natural look to the image, I chose short exposures so as not to oversaturate bright Venus. This made the crescent Moon's limb barely visible in the shots (see image, right). To compensate for this low contrast I had my planetary camera's gain set to zero, so the noise in individual frames would be as low as possible. Unfortunately, some low cloud moved in during the capture a few seconds after the Moon began to hide Venus, and obscured the scene. When the sky was blue again, Venus had totally disappeared, so I took more shots of the Moon, this time with longer exposures to better reveal the details of the lunar limb.

Stacking Venus