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 minutes. The procedure is simply to fix the
camera on a steady tripod or mount or clamp it to a post in your garden. Point it away
from lights, houses and trees at an area of sky and open the shutter for a few minutes.
Don’t exceed about 5 minutes, as background light, especially if you live in the
city, will fog the film. Ordinary film will do, but faster films allow shorter exposures
but can be grainier. An ASA400 or 800 film is a good compromise. Make sure the camera lens
is fully open – to the lowest f number. Try taking different duration exposures and
different areas of sky – pointing the camera at the pole star makes a good shot.
Once you have filled up your film with exciting images, you need to get
the film developed and printed. Here you will need to tell your processor to expect prints
that are black with a few dots and trails on, or he will probably scrap them all, telling
you they were all underexposed !! Alternatively seek out one of the specialist developers
that advertise in the astronomy magazines, but this can be a quite expensive option
(perhaps £25 - £30 for a typical roll of film).
What can you expect to see ?? Well using an unguided camera will mean
that as the earth turns the stars appear to move and will leave trails on the film and not
appear as points of light. These can be quite attractive and with short exposures it is
possible to recognise the constellations easily and record stars to well below those
visible by eye. It is possible to keep the exposures short enough so that the star
trailing is not noticeable, that is you appear to see points for the stars – try
using shorter exposures and find out the limit !!