With the right equipment, it is not difficult to take high quality astronomical images. The first requirement is, of course, a camera. Most people own some sort of camera and even with a simple camera and without a telescope it is possible to take some useful photographs, as long as the camera has a shutter which can be kept open for a few seconds. Keep the exposure short or the stars will become trails and not dots.
Put your camera on a tripod or balance it on something solid to prevent vibration. Point it at the sky area that you want to image. Set the zoom to minimum (wide field). Check your settings – Iso, focus, aperture. Use the camera's self timer to open the shutter, and don’t move the camera during the exposure. Take a series of exposures, 1, 2, 4, 8, 15, 30 seconds and look at your results. Exposure needs to be short enough so that rotation of the earth doesn’t cause the star images to become trails – zoom in to check
Up until now we have kept exposures short. If your camera will permit longer exposures you can image star trails caused by the earth’s rotation. The stars will appear to rotate around the Pole Star Polaris as the Earth rotates. Some nice images can be obtained of star trails with longer exposures.
Firstly you will
need dark skies & ideally no moon. Meteors always
appear to radiate from one point in the sky – the radiant. Ideally this needs to
be above the horizon.
Perseids in August and Geminids in December are the best meteor showers with
typically around 60 meteors/hour so try those first.
Point the camera about 30 - 45 degrees higher than
radiant. Meteors are faint – so
use a high iso setting - 1600 or 3200. Use the lens at
wide angle (low zoom). Try 15 or 30 second exposures
and take lots of images – examine them afterwards and hopefully you’ll
capture a meteor. If not you’ll have lots of star
pictures !
All you need is a camera on a tripod ! Point the camera so the moon is in the middle of the viewing screen. Turn the zoom to maximum so you can see the moon’s disk on the viewing screen. The moon is bright, so your camera will probably autofocus without a problem. If not go to manual settings and set the exposure to infinity. Use the self-timer to avoid camera shake and try an exposure and look at it. If too dark or light then adjust the exposure and try again until you are happy with the result.
A conjunction is when two astronomical objects come close to each other in the sky. This presents a good photographic opportunity. Check the astronomy magazines or use a Sky mapping programme like ‘Skymap’ to find when good opportunities are coming up.
There are lots of
earth-bound scenes that are quite easy and fun to image. Take a look at the
website by Richard Fleet from Newbury ‘Glows, Bows and Haloes’
www.dewbow.co.uk . Sunsets, Rainbows,
Haloes, Auroras, Notilucent clouds and many more are quite easy to photograph.
Think about composition. Play with the exposure until you get an image you like.
