Tips for Hongkongers on photographing total lunar eclipse this week
Look east for the full moon just before 8pm on Saturday and, if it’s clear in Hong Kong, you’ll see a strange sight – a “blood moon”. The rare total lunar eclipse – when the earth’s shadow completely covers the moon – gets far less attention than a solar eclipse. It is just as beautiful, though – the phenomenon occurs when our natural satellite is at its dazzling brightest – and it’s much easier to photograph.
The sunlight that still reaches the moon through the earth’s atmosphere gives the lunar surface a dull, reddish-orange appearance that can look stunning in photos (the science is the same as the reddening of a rising and setting sun).
The eclipse will last for a few hours, though from Hong Kong it will already be in progress before moonrise.
To witness the event, you’ll need to look directly east at 6.33pm from a hilltop. You’ll see a full moon rise that not only looks a lot less bright than usual; its lower right-hand side will already be red. That colour will spread right across the lunar surface as the moon rises higher in the sky.
By 7.54pm, almost the entire moon (save for a tiny glint of grey along the left-hand edge) will be coloured with crimson, pink, orange and red hues.
After some five minutes of totality the process will reverse, with the colour receding as the moon exits the earth’s shadow by 9.45pm.
That’s a long time to line up a photo. A good location might be the Space Museum in Tsim Sha Tsui, which is hosting a “Night of Total Lunar Eclipse” event from 6.45pm to 9.45pm. You should have a camera on a tripod well before the moon rises at 6.33pm. The easiest tactic is to use a telephoto lens or a telescope and just photograph the moon’s changing hues.
Try auto-focusing on the moon itself using the LCD screen, then switch to manual focus and use masking tape to secure the lens.
Set the camera at ISO 200 and the aperture to f/11 and attempt exposures of 1/60 second down to 1/15 second, and even to one second. From 7.54pm, when the moon is completely red, experiment with four-second exposures at ISO 800 and ISO 1600. Take a photo every 10 minutes and each one will show the moon to be a slightly different colour. You’ll also get stars around the moon, which are normally lost in the glare.
A smartphone can be used for a wide-angle shot, too, though if you’ve got binoculars, prop them up or mount them on a tripod and try taking a photo through one of the eyepieces.
A video – sped up later to create a 10-second time-lapse – can be dramatic, especially if you use a wide angle to capture the Hong Kong skyline.
There is one lunar eclipse shot that’s never been taken - the point at which the sun is completely eclipsed by the earth. It would make a wonderful photograph.
However, to witness that, you’d have to be on the moon.