Binocular Glossary

In our binocular terminology you will find the most important technical binocular terms. Of course, if you have any additional questions you may contact us via email at any time!

With this carefully thought-out STEINER strap attachment, the binoculars always remain firmly in the strap. The carrying strap, can, however, be released and refastened in one easy move. The comfort harness or floating strap can be switched quickly and easily.
The neoprene ClicLoc-carrying strap that can be fastened and released in seconds and its loops permit an easy use of a comfort harness (offered separately).

A high-quality coating delivers bright and crystal-clear images under even the worst light conditions. Coatings are applied in order to increase light transmission. In a very complicated and expensive process, thin layers of metal oxide are mounted to the prisms and lenses. The quality of a coating always depends on the number of the lenses and prisms are coated, the coating technology and the number of layers on each lens and prisms. STEINER is leading in coating technology.

Five different compass zones around the world.

Some roof prism binoculars contain a specially developed dielectric mirror with a vapour-deposited phase correction coating. This high-tech phase correction gives exact resolution of detail and true colours. It also reflects up to 99% of incoming light. In addition, the dielectric mirrors prevent aging of the coating. Aging also means that there is a loss of light transmission after some time. The contours of these optics are always sharp and distinctly visible, even in poor light or at the onset of dusk.

The Distance Control System guarantees fast and easy recognition of e.g. birds. Focussing takes place before you hold the binocular up for viewing. When observing, the distance to the object it can be read off in the binoculars at any time. If desired you can preset the distance even before you start looking at the object. This gives you more valuable time for identification.
STEINER Distance-Control-System gains valuable time where fast reaction is required: once the estimated observing distance is pre-set on the scale of the non-slip XL focusing wheel, no more than a little fine tuning is necessary.

The STEINER Wildlife XP 10×44 and 8×44 models deliver sharper images than any other binoculars thanks to its STEINER Precision Setting. This system allows you to focus both eyes independently of each other. It’s done directly at the ocular, and thus a perfect image is created for each eye. The STEINER Precision Setting allows massive differences in dioptre strength on each eye to be compensated for. Simply set the dioptre strength for each eye and you will always see sharply without having to readjust. Those without vision impairment simply set the control to zero.Simple to operate.

Optimum shielding from side light! They also deliver a very bright and vivid image. Like all of STEINER’s eyecups, they are made of soft, smooth silicone that is kind to the skin. The eyecups can be completely folded down, so allowing you to use the entire field of view if you wear glasses.

Maximum viewing comfort — without distracting side light! The STEINER Eyecups automatically adapt to the face, which improves handling and ensures a stable image. The silicone rubber makes them extremely comfortable and with the fold-down feature they are ideal for eyeglass wearers.

The exit pupil is the magnified image in the eyepiece and it is extremely important how its diameter relates to the pupil size of your eye. It determines the quantity of light reaching the eye.

The formula to get the diameter is: objective diameter divided by magnification, e.g. 7 x 50 binocular = 50 : 7 = 7.14mm.

The larger the exit pupil’s diameter the brighter the observed image in situations of low available light, since the eye pupil size rises (approx. 7mm at young age; approx. 5mm at age 50). On a bright day an exit pupil of approx. 2.5mm to 4mm is the optimum. The exit pupil does not relate to other factors of a binocular.

A small movement of the central focussing wheel with your finger is all that‘s needed to recognise details from close-up to infinity quickly and with absolute sharpness. The Fast-Close-Focus completely bypasses the need for clumsy and time consuming turning of the focussing wheel. The focusing knob with stepless, attenuated adjustment makes focusing quick, smooth and easy even when wearing thick gloves in bitterly cold weather. With an excellent close focus range, an extremely comfortable handling with perfect focussing in an unbelievably short time is provided.

Looking through a binocular, the widest dimension of circular viewing area that you can see is described as the field of view. It is usually measured in meters. The field of view will decrease as the magnification increases. Field of view is mainly determined by the optical design of the eyepiece.

Fluoride glass is made of the mineral calcium fluoride and significantly improves contrast and colour fidelity. The images are crisply sharp and of the highest contrast right to the edge of the field of view. Contours are always clear and easily made out; incidental light is reduced to a minimum. Unlike conventional optical lenses, fluoride glass corrects imaging and colour errors much better. You get high-contrast and absolute bright images with natural colour definition. The STEINER models Wildlife XP 10×44, 8×44 are equipped with fluoride glass.

The largest available, extremely stabilized HD-compass ever to be fitted in binoculars. The size of the compass guarantees most accurate bearings. Giving you just that little bit of extra safety on the high seas. Fluid damping and illumination make it possible to fix your position under any extreme condition imaginable.

STEINER’s High-Contrast-Optics provides outstanding viewing quality and are exceedingly good value. They are perfect for both beginners and passionate professionals. All lenses and prisms are manufactured with maximum precision and are specially coated and deliver optimum observing results. Such state-of the art optical technology guarantees absolutely bright, high-contrast and sharply contoured images with natural colour definition.

The exceptional optical formula is our own development using the purest index matched glass, and coatings using rare-earth formulations of titanium, fluorite and other mineral substrates. The result is not only a first-class light transmission and a remarkable brightness — the images are crisply sharp and of the highest contrast right to the edge of the field of view. Contours are always clear and easily made out; incidental light is reduced to a minimum. Perfect, high resolution observing results are guaranteed, even under the worst weather conditions, in poor light or at the onset of dusk.

STEINER Ultra-HD-Optics with highest manufacturing precision and high-end fluoride glass for extraordinary colour fidelity, highest detail resolution right to the edge and optimized, clear contrast. Delivers razor sharp images, topclass light transmission and 3D brilliance with sculptural images and excellent depth of field. Great field of view for a perfect overview in any situation.

The luminosity factor is calculated by dividing the aperture by magnification and then multiplying it by 2. The higher the factor the brighter the images in low light conditions.

It is calculated by dividing the focal length of the objective lens by the focal length of the eyepiece. A high magnification usually results in a narrower field of view. The maximum use of a magnification also depends on factors such as the quality of the lenses and the prisms.

Makrolon® is a glass fibre polycarbonate thermoplastic molding compound known for its high heat resistance, dimensional stability and toughness.

The handy grating of the Memory-Ocular optimises your personal dioptre setting. By turning the ocular the user finds the dioptre setting in the blink of an eye. Increased ease of use and fast adaption to changing situations are guaranteed.

Unsurpassed clear vision is offered by the proven STEINER Nano-Protection®. It provides the lenses with a dirt and water resistant surface, protecting them against aggressive environmental effects. Rain, salt-water, snow and moisture are eliminated from your view by this repelling layer. Cleaning is considerably simplified and hard-to-remove dirt becomes a thing of the past. The ultra-thin hydrophobic surface treatment on the objective and ocular lenses is extremely robust and ensures that your binoculars will deliver high-contrast brilliant images across the decades.

Rough weather, cold hands, strong wind are extreme forces for you and your equipment. With the NBR-Longlife rubber armouring you master every condition.

This chemical formula is not only extremely robust, it also gives you a very good grip, in cold, heat, rain, sea water and the sun‘s rays. For a perfect grip, the rubber composite should be soft and non-slip, but on the other hand, the harder it is, the more durable it will be. The NBR-Longlife rubber composite is a perfect solution that makes the binocular a pleasure to hold. It is resistant against oil, acid, salt water and even bird droppings. A rubber armouring that is at the same time soft, non-slip and prevents annoying noises.

The new NBR-Longlife rubber armouring guarantees an even longer life for your binoculars at maximum ease-of-use.

Fogging up or the formation of condensation inside the binoculars is totally prevented by this high-tech solution. Even temperature variations between -40°C and +80°C do not have any adverse effects on the functionality of STEINER nitrogen-filled binoculars. The unique 2-way-valve technology makes inspection, service and maintenance possible even after a number of years. Your binoculars are always ready for action under the most extreme conditions or in the worst weather conditions. Optical quality and precision are maintained for decades.

The aperture is the binocular’s objective lens, usually measured in millimeters, e.g. 7 x 50 = 50mm. It is directly related to the size and weight of the binocular. The larger the diameter the more light gets in and the brighter the image.

The lens closest to the viewer’s eye.


The first number is the magnification, describing by which factor an object was magnified. For detailed inforamtion please click on the section ‘magnification’. The second number is usually measured in millimeters, e.g. 7 x 50 = 50mm and is called ‘aperture’. For detailed inforamtion please click on the section ‘objective diameter’.

Porro-prism systems are used in almost all of the high-quality binoculars. These binoculars are extremely rugged. This system creates a perfect three-dimensional image and its construction increases light transmission.

The precision reticle is visible in the entire angle of view and gives measurements in metres or feet (0.33 m).

Measuring distances:

You sail along the coast and see in your map the height of a lighthouse in front of you is 40 m. You apply the lighthouse and read the value 20 from the number scale of the reticle. The distance to be calculated is the actual size, 40 m in our example, divided by the read size, 20 m in our example, multiplied by 1000. 40 m / 20 = 2 x 1000 = 2000 m. Thus, the lighthouse is at a distance of 2000 m.

A second example for the horizontal scale: You see a port entrance in front of you. You know it is 80m wide. Now you apply the portside light of the harbour on the left side of your reticle and read for the starboard side light a value of 60. The distance to be calculated is the actual size, 80 m in our example, divided by the read size, 60 m in our example, multiplied by 1000. 80 m / 60 = 1,3 x 1000 = 1300 m. Thus, the lighthouse is at a distance of 1300 m.


distance = actual size / read size x 1000

actual size:

actual size = distance x read size / 1000

1 nautical mile = 1,852km

Roof-prism binoculars split the light entering into two separate paths. By design these binoculars are extremely compact, smaller and more streamlined in size.

STEINER binoculars are sealed by a special sealing technology. This prevents the penetration of moisture, dust, dirt etc. inside the binocular body. By this technology your binocular investment and the high-end optics are safe for years and ideally protected in any situation.

Our Comfort Grips for your thumbs ideally combine comfort with a firm grip on the binoculars. The lightweight and comfortable feel eliminates pressure points, particularly if you are observing for longer periods. At the same time, they give the binocular excellent balance.

The STEINER Sports-Auto-Focus makes handling particularly comfortable. If both eyes are of the same dioptre strength, simply set both of the adjusting rings on the eyecups to ”0“ and you will see clearly from 20 m to infinity. If not, adjust both oculars individually for razor sharp images. Once adjusted, everything will be sharp and clear from 20 m to infinity for varying distances. Simple use. Also with a single hand only.

Whenever light travels through a binocular, a certain percentage of it is lost through absorption and reflection. Transmission is the term which describes the percentage of light that is not lost through the optical system.


The twilight factor has the most significant impact on resolution or image details. It is a measurement to distinguish efficient viewing in low light conditions. The Twilight Factor is calculated by taking the square root of the product of the magnification and the aperture. The higher the twilight factor the better the resolution e.g. when viewing under low light conditions.

The Twist-up Eyecups offer optimum protection against incidental light from the side. They don‘t just block troublesome reflections, they ensure an extremely bright image. The three positions of the eyecups offer an ergonomic, a classic cylindrical and a position for people wearing glasses. If the eyecups do not fit exactly to your eyes, they can be adjusted as desired by the eyecup fine adjustment mechanism.

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Ahmad High way, First Ave., Jannat St., Jalal ale

Tel: (+98) 021 88014324-5

TelFax: (+98) 021 88014330

E-mail: –

To view our link to the main site of Steiner as representative Click here

Steiner Optik is a Beretta Holding Company. © 2016 Beretta, Inc. All rights reserved. Site by SajadTorabi

Legal | About | Contact Us


Sadotsun Gb

Ahmad High way, First Ave., Jannat St., Jalal ale ,Tehran, IRAN

Tel: (+98) 021 88014324-5

TelFax: (+98) 021 88014330

E-mail: –

To view our link to the main site of Steiner as representative Click here

Steiner Optik is a Beretta Holding Company. © 2016 Beretta, Inc. All rights reserved. Site by SajadTorabi

Legal | About | Contact Us