Bird watcher looking at a bittern through hide window, Leighton Moss RSPB reserve

How to choose a telescope

Telescopes are popular among birdwatchers. By offering higher magnification than binoculars, they add a new dimension to birdwatching. They can be expensive, so read our advice before making that purchase!

What to take into account

Telescopes come in component form - the body, eyepiece and appropriate support, usually a tripod. It is important to choose your equipment with care and thought.

The first step is to decide on the following:

  • how much do you want to spend?
  • are size and weight important?
  • what magnification and what type of telescope do you want?

These will give you good starting points when going to a shop to make your choice.

Field days

The RSPB runs field days where you can try binoculars under field conditions. This will help you to make sure you are completely happy before purchase. The shops on reserves listed on the right keep a good range of binoculars. Contact them directly for details of products and events.  You can also follow the link (top right) to see if there's an equipment demonstration near you soon.

Alternatively, follow the link on this page to visit the RSPB online shop. Don't forget, all sales will benefit our conservation work and help birds and wildlife!

Basic guidelines

  • For general use, choose a compact 60 mm telescope with a wide angled 20x or 22x eyepiece. 
  • If you need higher power, choose a 30x or 40x eyepiece in addition to, but not instead of, the general one. 
  • The larger 75-80 mm telescopes are ideal for use in low light or from a fixed position such as a hide. Again the wide-angle, fixed 20x-30x eyepieces are the best, but a zoom works well with this type of telescope. 
  • If you wear spectacles, choose an eyepiece which has a fold-back rubber or pull-up eyecup, although you will still lose some field of view. 
  • Many telescopes suffer from a greater or lesser degree of colour fringing (when objects are outlined with a coloured hue - which may only be apparent at higher magnifications). The low-dispersion (ED) glass in some of the more expensive models eliminates colour fringing and gives a brighter and sharper image.

Once you have made your choice, the following points will help you get the most from your telescope:

  • Whenever possible, use a tripod or other support; remember you can use a tripod only partially extended while sitting down, or kneeling: useful in strong winds or in wide open spaces.
  • Learn to use either eye; learn to use with both eyes open to reduce eyestrain over long periods.
  • Use the telescope like the barrel of a gun to line up the bird you are trying to see. Some telescopes have a sight line to help you do this.
  • It is important to care for your equipment correctly to ensure it gives you good service for a long time.

Straight or angled 'scope?

Most telescopes come in either straight or angled form. On the straight type, the eyepiece follows the light path from the objective lens. On the angled type, the eyepiece is at 45° angle to the telescope body. Both designs have their advantages:

Straight

  • easier to find what you are looking for
  • sometimes cheaper than the equivalent 45° model
  • better to use when sitting down in hides

Angled

  • easier to follow moving birds
  • often avoids straining the neck
  • easier to watch birds in treetops
  • easier for tall people to look through it on a tripod
  • the tripod does not have to be erected so high and is therefore more stable
  • The angle of the eyepiece does not affect the performance of the telescope and your choice is a matter of personal preference.
Aren't Birds Brilliant scheme at Seaford, Sussex

What magnification do I need?

Telescope magnifications generally range from 15x to 60x. Some specialist instruments offer even higher power. If the telescope has a fixed eyepiece, 20x or 30x is normal.

Most telescopes on the market have a range of interchangeable eyepieces available, so you can choose more than one. Wide-angle eyepieces of 20x to 30x are good for general use; a 40x might be useful for longer distance work.

When using higher magnification, the image brightness and field of view decrease dramatically. The shimmer in the air can also be a problem, and any shake from the support becomes more evident. In practice, this means that the higher power eyepieces are best used in bright conditions for stationary birds. Bigger is not necessarily better.

Zoom eyepieces work well with some telescopes, usually the ones with a larger objective lens. The range covered can be 15x to 40x, or 20x to 60x. But remember, on the higher power, the amount of light passing through to the eye will be reduced.

The smaller telescopes have 60 mm objective lenses and, because this makes them compact, they are ideal for general work. A 20x or 22x wide-angle eyepiece will maximise the light reaching the eye.

Some manufacturers offer telescopes with larger objective lenses, between 75 mm and 80 mm. These perform better in low light, but the large lens adds to the size and weight of the instrument. Because of the increased light transmission, zoom eyepieces are better suited to this type of telescope.

Birdwatching at Exe Estuary, Devon

Can I use my telescope for photography?

In most cases, yes, but it is worth remembering that a telescope is designed to look through, not for taking pictures, and the results will not be as good as with a true camera lens.

The advent of affordable digital cameras has meant that birdwatchers have developed a technique called 'digiscoping' when a digital camera is placed onto the eyepiece of a telescope, effectively using the camera as a long lens.

The results depend on how well the camera and telescope work together. Cameras with zoom mechanisms that are internal, not external, work much better.

Larger objective telescopes work best, as more light gets into the camera, bringing a faster shutter speed. A low magnification eyepiece is best, as they offer a brighter image.

Make sure you use a good tripod, as any movement will cause camera shake and blurred pictures. It is important that there is as little movement as possible; there are various gadgets available to hold cameras securely in place, or some digiscopers create their own.

If you are intending to buy a camera which is good for digiscoping, take your telescope to the shop with you, and try it out!

Man with Telescope, British Birdwatching fair

How much should I pay?

The starting point for a good 60mm telescope with a fixed eyepiece is £250. Add £100-150 for a zoom eyepiece.

From £250 to £500, you will find better telescopes and this is the starting range for the instruments with larger objective lenses.

Over £500 buys you a telescope of the highest quality. Some top-of-the-range instruments have low-dispersion (ED) or fluorite glass. 60mm telescopes with this type of glass will out-perform larger models.

Be sure to take into account the cost of a good tripod when making your selection. A telescope is only as good as its support.

Some telescopes are waterproof, but it is worth getting a case. Stay-on cases are a good idea and are available to fit most models. These offer better protection against the elements and help protect against knocks.

Boy looking through telescope at The RSPB shop at Darts Farm, The Exe Estuary Centre