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What is Observational Astronomy?

Observational astronomy is essentially every time you look up at the night sky and think about what you see. You don't need any equipment to be an observational astronomer, just your unaided eyes.

The constellations can easily be identified with the unaided eye. Some deep sky objects and double stars can be discerned without optical aids, and if you have exceptionally good night vision, you can see even more. However, to see details on the moon, or a disk on the planets, or clearly see deep sky objects, you will obviously need some aids to your eyes.

This page intends to go through the different stages of observation and how to get the most enjoyment out of each stage. It will make recommendations on equipment and techniques that are unique to the contributors from their personal experiences and are not necessarily an official AFA position.

The reader can take or reject the advice given and can spend as much, or as little, money on equipment as he or she likes to suit the household budget and observational interests.

AFA cannot in any way accept responsibility for injury or loss incurred in following information or recommendations gleaned from this page.

Naked Eye Observing

Most people would say that naked eye observing is not really astronomy at all. I personally would strongly disagree with this statement. For any serious astronomy to be achieved, an observer must be familiar with the night sky, the relative positions of the constellations, stars and other deep sky objects, and the wandering components of the night sky, i.e. the Moon, planets, comets and asteroids, and even artificial satellites.

For years, I had a solitary interest in astronomy, gaining knowledge mainly from books. However, when I went outside, I could only identify a very small number of constellations, e.g. the Plough and Orion. It wasn't until I went out observing with an experienced observer and had several adjacent constellations pointed out to me that, suddenly, I appreciated the sense of scale and could then quickly identify many more constellations by myself.

I think it is very important that, when starting out in the hobby of astronomy, you talk to, and get advice from other more experienced amateur astronomers. If possible, join your local astronomical society. It's amazing what you can quickly learn from other people with similar interests and different experiences.

It's also a good idea to take notes every time you go out observing and keep a log of what you've seen. For note-taking outside at night, I find a personal cassette recorder very handy. Nowadays they are very cheap. It's also a good idea to take a spare set of batteries with you if you're going to be out a long time as batteries go flat very quickly as the temperature drops.

Check out the current conditions for observing

Binocular Observing

To most people, looking at the stars conjures up visions of standing in an Observatory looking through a telescope. In doing so they are overlooking a very useful observing tool. The humble pair of binoculars.

If you have never studied the heavens before, it's a good idea to start with a pair of binoculars, they need not be expensive either. You'd be amazed how much more you can see once you appreciate how to use them. Too many people buy a telescope without knowing what it is that they really want to do. Binoculars are also very handy to have around even when using a telescope. Quite often you may have trouble pointing the telescope towards the direction of the target. A glance through the binoculars and you can find your way around by 'star hopping'.

But, you may ask, is there an Ideal Pair? We would recommend 10 x 50's. They give you 10 times magnification and 50mm lenses to give a bright wide view. Newcomers to astronomy can learn to find their way around the universe. A pair of binoculars and a star map or good book such as Collin's 'Stars and Planets' are all you need.

If you use binoculars to study the sky, and you get a crick in the neck when using them either handheld or tripod mounted? The answer, get a fairly large mirror, a comfortable chair, and look down, not up! Place the mirror on the ground to reflect the area of sky you want to study, sit in the chair, rest your elbows on your knees, hold the binoculars near the front lens and look at the mirror. you'll find it's quite comfortable and nearly as steady as using a tripod. Of course, you can use a tripod, which makes it even more comfortable and steady.

Getting Started in Astrophotography


To get started in astrophotography you don't need much in the way of equipment. A camera is required of course, and can be of any type, as long as it has manual control of the aperture (or at least some manual override) and a "B" shutter setting. This shutter setting enables the shutter to be kept open for as long as you press the shutter release. Although almost any camera can be used the best type is an SLR Single Lens Reflex that allows the changing of the lenses, so that a telephoto lens can be used to show a smaller area of the sky. It is best to avoid automatic cameras as the electronics, or at least the battery can fail in the low temperatures that the camera can be subjected to in the cold nights of winter. Having said this, to get started, so long as there is a "B" setting any camera will do. If the camera allows interchangeable lenses you should use either the standard lens or wide angle. To use telephoto lenses requires some form of driven mount.

Shutter Cable Release

As you can imagine, if you used your finger on the shutter button you will almost certainly move the camera. So to avoid this a shutter release cable is used. This is a flexible cable that screws into the release button, it has a plunger at the end which when pressed operates opens the shutter. Some of these cables have the feature of being able to lock the plunger down during the exposure so that you don't have to keep pressing the plunger for the whole of the exposure. The above described a manual cable release, there are now electronic versions which are basically a button on the end of a length wire.


A tripod is required so that the camera can be pointed at the region of sky you wish to photograph. But before spending money on a tripod you may wish to 'have a go' without. You could fix the camera to something secure such as a garden fence with nothing more than some adhesive tape, but it does make it more difficult to aim the camera and also to operate it. (make sure the tape does not leave the adhesive on the camera when you remove it. If a tripod is do be used the camera must have a tripod bush on its underside. There is really no substitute for a good strong tripod that does not wobble when touched. If the tripod is not firm the resulting photograph will be disappointing. Its a good idea not to extend the tripod too far, so be prepared to get down on your knees.


I should mention here one of the main difficulties in taking astro-photos. The Earth is continually spinning, which causes the stars to appear to move across the sky. This limits the maximum exposure that we can give before the star images start to trail on the film forming arcs instead of point images. In order to give long exposures, typically longer than 30 seconds with a standard lens, a special type of mounting needs to be used to move the camera in the opposite direction of the Earth's rotation. The use of such a mounting is out of the scope of this getting started article, and will be addressed in a further article. As the exposures need to be fairly short and the stars are faint this necessitates the use of a fast film, typically over 100 ISO. It you tried to use a slow film you may only record the brightest of the stars, or none at all. A good film to start with would be around 400 ISO slide film, I say slide film in preference to print film because most processing labs do not do justice to images of the night sky.


As the maximum exposure time is limited by the Earth's rotation, we generally try to give the maximum exposure possible to record as many stars as possible. The lens aperture also needs to be open wide, so set the aperture to its maximum setting, i.e. if the lens has apertures f2.8 to f22 set the lens to f2.8. A typical exposure that does not show trailing of the stars is about 20-30 seconds. You may be able to extend this time to 45 seconds. The maximum length of time you can expose for is somewhat dependant on where the camera is pointing. If you are photographing the sky near the celestial pole, (near the Pole star) then longer exposures can be taken as the stars move shorter distances for a period of time, where as near the celestial equator the stars are moving further in the same time span.

Try this site for more information on astrophotography by Russell Cockman.

Recommended Films

Black & White Kodak Tmax 100,400,3200

Kodak Technical Pan

Colour Print Fuji Superia 100,200,400,800

Kodak PJ 400

Kodak Royal Gold 1000

Colour Slide Kodak Elite Chrome 200 / 400

Fuji Sensia 200,400,1600