BIRDWATCHING: BIRD WATCHING AND DIGISCOPING

WHAT MAKES BIRDWATCHING SO POPULAR?

There are about 10,000 bird species worldwide - birdwatchers therefore keep a "lifelist" of how many bird species they have observed themselves. Happy birdwatchers are happy to have about 300-500 birds on their "Lifelist".

There are many famous people who have discovered birdwatching for themselves: Teddy Roosevelt, Van Morrison, Prince Philip, Agatha Christie, Margaret Atwood, Steve Martin, Cameron Diaz and Fidel Castro or the former US President Jimmy Carter.

WHAT DO I NEED FOR BIRD WATCHING?

Birdwatching is usually done with binoculars or spotting scopes but the so-called digiscoping is also popular, in which a digital camera is mounted on a spotting scope to document the observations.

Most observers start with binoculars, as this is easier to handle as an introduction and makes it easier to get started.

In order to be able to go into more detail later, we would like to briefly explain the most important terms of sport optics.

THE KEY FIGURES IN THE DESIGNATION

How much we see with binoculars depends on the magnification and the diameter of the lens. The first number of binoculars indicates the magnification, the last number the lens diameter. Thus the Bresser Pirsch ED 8x42 binoculars have a magnification of 8 times and an objective lens diameter of 42 mm. For observations in twilight the relation between objective diameter and magnification is important. However, one cannot say the higher the magnification, the better the binoculars are, as the detail recognition is greatly reduced when using binoculars with high magnification. This may be due to the "co-magnified holding movements" or the poor image quality.

In contrast to the magnification, the objective lens diameter is very much a quality criterion of binoculars, because the higher the one objective lens diameter, the greater the incidence of light and therefore the brighter the image. However, you should always keep the actual purpose of the binoculars in mind. A diameter of 21 mm (8x21) is sufficient for daytime observations. However, if observations have to be made during twilight, the binoculars should have a diameter of at least 50 mm.

These characteristics are only interesting for a comparison of different types of binoculars (8x30, 7x50, 16x50 etc.). They result in all the formulas needed for comparison. They do not say anything about the quality of a pair of binoculars and do not take into account any increase in performance due to coating or higher quality glass types.

THE EXIT PUPIL

The exit pupil is the bright image point which hits the eye of the observer at the eyepiece side. This exit pupil is of immense importance for twilight vision.

The larger it is, the brighter the image in your eye appears. It is calculated by dividing the objective diameter by the magnification. With 7x50 binoculars this would be:

The maximum opening of the pupil of the human eye depends on the eyes and the age of the observer. The ability of the pupils to enlarge in the dark decreases with age. The pupils of a young observer can still dilate to about 7 mm, but in a 50-year-old observer only up to about 5 mm. In this case the nature observer cannot use the wider exit pupil of 7x50 binoculars and should better choose a lighter 8x40 binocular with an exit pupil of 5 mm. However, it can also be an advantage for older people to choose binoculars with a high exit pupil. When observing "out of motion" or on a boat (moving location), the observer's pupil (which only widens to about 2 mm during the day) does not get outside the exit pupil diameter so quickly and "shadowing" of the field of view is avoided.

Calculation

(Objective lens diameter/magnification)
for example: 50 : 7 = 7.14

THE TWILIGHT FACTOR

Most of the time it is animals that can only be observed during twilight and especially at this time of day the lighting conditions are not ideal for observations with the naked eye. Binoculars must therefore be all the brighter so that details can be seen even at dusk in the morning or evening hours.

Twilight factor

Binoculars must already have a magnification of at least 8x and a corresponding objective lens diameter of at least 56 mm to do justice to this "twilight performance". The power to be able to make observations even at twilight is indicated in the twilight index.

This is a standardised value for the comparison of optical devices with regard to detail recognition, especially in poor lighting conditions. The higher the twilight factor, the more light the device emits.

The twilight factor is calculated from the square root of the product of magnification and lens diameter. This means with 7x50 binoculars:

Calculation

(square root of magnification x lens diameter)
for example: root of 7x50 = 18.71

THE EXIT PUPIL DISTANCE

It indicates how far away the eye may be from the eyepiece without losing sight of the full field of view. The interpupillary distance can be changed with almost all binoculars by folding rubber eyecups or by rotating or pulling out eyecups. This means that binoculars with these so-called "spectacle wearer eyepieces" can also be used by people who wear glasses. It is important that the exit pupil of these eyepieces is positioned as far back as possible (13.5-20 mm).

THE FIELD OF VIEW

In most binoculars, the field of view size (in addition to magnification and lens diameter) is also printed on the body of the binoculars. In Europe, the size of the field of view is usually given in m at a distance of 1000 m or otherwise as an angle. If binoculars have a field of view of 101m/1000m, the observer will see a 101m wide or round field of view at a distance of 1000 m.

Field of view

The higher the magnification, the smaller the field of view. With binoculars that do not have any special systems (e.g. mirror prism system) but nevertheless have a very high field of view, the edge sharpness can sometimes "suffer". This can be checked when observing fine continuous structures (walls or fences) by comparing the sharpness from edge to edge (you must stand straight in front of the object of observation when checking). If the field of view is given in degrees, the corresponding "metre value" can be calculated by multiplying by 17.45. A field of view of 101 m thus corresponds to 5.79 degrees.

THE FOCUS

A distinction is made between binoculars with single eyepiece adjustment and those with central drive (central focusing). Binoculars with central drive can be adjusted faster and moving objects can be followed more quickly. Prism binoculars with single eyepiece adjustment are mostly used for marine applications. However, waterproof models with central focusing are now also available. Because of the speed of focusing, birdwatchers prefer to use central focusing or also called centre drive focusing.

THE RUBBER ARMOURING

Binoculars with rubber armouring are recommended for tough, professional use. The rubber armouring protects the binoculars against impact, falling and splashing water. The rubber armouring of all BRESSER binoculars is lightfast under normal use and insensitive to sunlight.

WHICH BINOCULARS SUIT ME

Now the question arises as to which construction method is particularly suitable for birdwatching. It should be known that the type of prisms used determines the design of a prismatic glass. The use of Porro prisms results in wide binoculars, but these are not too high. Due to the larger lens spacing in the Porro system, the object to be observed looks a little more plastic. This is most noticeable at high magnifications and at shorter distances. However, binoculars with roof prism system are more compact and handier.

Which design is better suited for birdwatching should be decided by each individual based on the following advantages and disadvantages.

PORRO-BINOCULARS

ADVANTAGES:

Light transmission very high

Cheaper than roof binoculars

Good close focus

NEGOTIATIONS:

Mostly no internal focusing

High weight

Chunky housing

ROOF-EDGE BINOCULARS

ADVANTAGES:

Very compact shape

Often waterproof and filled with protective gas

Central Focusing

Very easy handling

NEGOTIATIONS:

Slightly more expensive than Porro prisms, due to the larger primer system

THE SPECTIVE

The spotting scope can be a real alternative to binoculars, especially for bird watching, as they are very versatile and powerful. This makes it perfect for observing birds of prey, garden birds, sea birds and waterfowl in nature. A spotting scope is particularly well suited for observation from a long distance, so that detailed images can be seen even from distances of over 30 metres.

The spotting scope can be a real alternative to binoculars, especially for birdwatching, as they are very versatile and powerful. This makes it perfect for observing birds of prey, garden birds, sea birds and waterfowl in nature. A spotting scope is particularly well suited for observation from a long distance, so that detailed images can be seen even from distances of over 30 metres.

Special attention must be paid to the eyepiece when using a spotting scope, as this can either be replaced or used as a zoom eyepiece on higher quality spotting scopes. A higher magnification is necessary if you want to study distant birds, while with a lower magnification you can see short distances well.

With spotting scopes there are no major differences in construction. The only difference is the view of the spotting scope, which is either straight or sloping. There is no difference in performance between the two types of spotting scopes, but much more the own preference. The oblique view is often more comfortable, while the straight view provides better orientation.

HOW DO I FIND A SUITABLE TRIPOD FOR BINOCULARS OR SPOTTING SCOPES?

Ideal bird watching with a spotting scope is only possible with a good tripod. After all, what use is a very high-quality spotting scope if the tripod is only average and thus wobbles, falls over in the wind or is difficult to handle?

In combination with a good tripod, birds can be observed in peace and quiet without any annoying wobbling. Therefore you should pay attention to the following points when choosing a tripod.

1. The tripod should be stable so that it stands securely even in light wind. Therefore we generally recommend tripods.

2. The weight must fit in relation to the spotting scope, i.e. not too light, but also not too heavy

3. Leichte Verstellbarkeit in alle Richtungen 

4. Easy adjustability in all directions

5. Different height settings

DIGISCOPY

Nowadays, digiscopy, which describes photography through the eyepiece, is becoming increasingly modern. Through digiscopy, observations can be documented very simply and also shared with friends. Many manufacturers and suppliers advertise with integrated smartphone holders, which make it especially attractive for beginners to start bird and nature observation. Condor spotting scopes are ideal for connecting a single-lens reflex camera to a spotting scope. Thanks to the large eyepieces and the matching adapter for Canon EOS or Nikon, you will quickly be able to capture exciting images.

WHAT DO YOU HAVE TO PAY ATTENTION TO WHEN BUYING AN OPTIC FOR THE FIRST TIME?

Before you can really get into birdwatching and nature observation properly, you need to get to grips with the purchase of an optic in order to achieve the best possible results even as a beginner.

Below we have summarised the most important criteria when buying an optic.

1. make it clear for which purpose you need binoculars or spotting scopes Is it just for observing birds in your garden during the day or do you want to observe birds of prey in forests at dusk? The magnification and lens diameter are then selected according to the intended use. For observations during the day, i.e. when there is sufficient brightness, a smaller objective diameter is sufficient, whereas for observations at twilight the objective diameter should be sufficiently large.

A magnification of less than 8x is not very useful for birdwatching, because the detail recognition is too low. In addition, a magnification of more than 10x is also of little use, as not many people can guide such binoculars smoothly and without wobbling. Therefore, binoculars with 8x or 10x magnification are perfectly suited for bird and nature observation.

2. weight and size should also not be neglected in the purchase decision, as the binoculars are usually used for several hours and comfort should not be compromised. A compromise has to be found to achieve an optimum balance between weight, size, magnification and image quality. Here too, the actual purpose of use must always be kept in mind. Often a carrying strap is included in the accessories, which makes observation easier and less stressful. Check it for stability and tear resistance.

3. clarify which design suits you best. Due to the explained advantages and disadvantages of the porro- and roof-edge construction make your own overview and decide early on what exactly you want.

4. Then compare the suppliers on the market and their products. There are now a great many specialist or online retailers who specialise in the sale of binoculars and optics, so that customers have much more transparency than was the case some time ago. Also pay attention to the warranty of the different suppliers, because it is often, especially with high-quality optics, much higher than the legal warranty.

5. compare the prices. Even if you have already decided on a certain optic, you can save a lot of money now and then by simply comparing the prices.

6. comparing prices makes sense, but you should still be aware of the following wisdom: "He who buys cheap, buys expensive! This is especially true for optics, because if you have a poor quality optic, you will quickly become dissatisfied and may even lose interest in bird and nature watching. For a satisfactory observation and good binoculars you should already have some money in your hand. After all, you are investing in your hobby and for bird watching there is nothing more important than good optics.

7. finally, it is important that you test the products for their operation and handling. You can talk to advisors and try out different models and price ranges.

HOW DO I USE MY OPTICS CORRECTLY?

Good binoculars are required for bird and nature observation. They should have a central focus mode (central drive) and dioptre compensation.

To ensure ideal use, you should observe the following points, the more you can always see a sharp image.

1. adjust the eye cups: Today, most binoculars have eyecups that can be turned out or folded down. These eyecups are only responsible for the correct distance between the binoculars and the eye, which ensures that the image is complete. Now it is important to consider whether you wear glasses or not. Spectacle wearers must turn or fold the eyecups in or out in order to achieve the optimum distance. Otherwise the eyecups should be folded out or turned.

2. dioptre compensation: With binoculars with a centre drive setting, the right eyepiece (with most zoom binoculars, the left eyepiece) can be rotated. This allows the user's defective vision to be compensated. On models with single eyepiece adjustment, both eyepieces can be rotated and are also used for focusing. Accordingly, one focuses on an object at a short distance, closes the left eye and rotates the right eyepiece until the image is clearly visible.

3. set the correct width: The width of a pair of binoculars describes the distance between the individual eyepieces and should be adjusted so that an overall round image can be seen by both eyes independently. To do this, aim at a distant object and adjust the distance between the eyepieces until a clear, round image can be seen.

4. focusing: After the previous steps, you can now very simply aim at an object and focus on it with the central focusing wheel.

After these steps, you can focus on targets at different distances easily using the centre wheel without changing the other settings. This is particularly important when birdwatching, as you can only rarely observe birds at their leisure. Therefore, a quick adjustment of the focus must always be a basic requirement.

THE BIRD WATCHING

Actual birdwatching does not only begin with binoculars in nature, but much more with the preparation at home. To find and identify as many birds and bird species as possible in nature, you should prepare yourself at home with a special bird identification book. These books are already available at reasonable prices and ideally even come with a picture index.

Once you have gathered enough information, you can set out into the wild and start observing. It is important that in our diverse world you always walk around with your eyes open to discover new things and especially birds. We therefore recommend that you always have a notebook to hand to be able to document new findings and observations directly. For this purpose you can make notes on their appearance, behaviour, whereabouts but also on their sounds.