STEP-BY-STEP GUIDE
STEP 1 You don’t need expensive kit to take pictures of a conjunction: a DSLR on a fixed tripod and a remote shutter release will get you started. Some point and shoot cameras may work on the Moon and bright Venus, as will some camera phones. For more sophisticated shots involving longer exposures, you’ll need a tracking mount.
STEP 3 If you have a tracking mount, close the lens aperture to f/8-f/22. Set the ISO relatively high (800-1600) and take an extended shot of Venus. The result should be a bright planet at the centre of a starburst effect. This also works well with the Moon. Experiment with exposure, starting with a 10-second shot and adjusting settings as in Step 2.
STEP 5 DeepSkyStacker can be used to apply the flat frames to the main shots. Alternatively, using a program such as Photoshop, load the main image with the flat field in a separate layer above it. Set the blend mode of the flat image to ‘Divide’ to remove the unwanted image field artefacts. Converting the flat image to black and white can reduce colour shift issues.
STEP 2 Set the camera and lens to manual. Focus the lens on Venus or the Moon, and set camera sensitivity to medium-high (ISO 400-800) and lens aperture to a low f-stop value. Close the aperture by a stop or two if the image looks distorted. Take a four-second shot. If overexposed, reduce exposure or ISO. If underexposed, increase exposure or ISO.
STEP 4 If you find artefacts such as dust spoiling your twilight shots, take flat frames. Using the same f/number and focus settings, point the camera at an evenly lit patch of clear sky and take an image. Its histogram peak should be around the 75 per cent mark. Moving the camera while taking the shot will reduce the probability of imaging stars as bright points.
STEP 6 If using a basic untracked setup, placing a foreground object in front of the conjunction can help to give it some context. Conjunction shots taken in an urban environment can look amazing, emphasising the contrast between the human world merrily going about its daily business while the celestial show takes place in the sky above.