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Binocular Professionals

 Binocular Basics

Important Criteria In Choosing Binoculars

At first glance, the numbers and terminology used to describe binocular specifications and optical performance, sound complicated. But don't be intimated! There are only a few definitions and numbers which must be understood to make the right binocular choice for maximum results. To help you determine which binocular is right for you, our factory trained binocular expert has compiled the list of the most important aspects of binocular use. Our expert reputation has come from our dedication to educating the intelligent consumer who values their quality of life and for those professionals who value their professionalism and reputation.

Combine Our Extensive Experience In Selling And Using Binoculars; Our Professional Binocular Consultants; Largest Selection of The World's Quality  Brands And Best Manufactures;  And Our Exclusive 30-Day Free Trial Program, And You Will See Why Casanova's Is The Premiere Dealer of Choice & Outfitter To Professional's, Law Enforcement, US. Government And People Of Higher Distinction.

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• 8x20, 10x25, 8x42, 10x50, .....
• Light-Gathering Capability

The first number used to identify a binocular is the optical magnification of the binocular. Magnification is a measure of how much closer an object appears to the viewer. At an 8x magnification, an object situated at a distance of 100 m [328 feet] appears to be as large as if it were only 12.5 m [41 feet] away (100 : 8 = 12.5); [328 : 8 = 41].

The second number indicates the diameter of the lens in millimeters. The larger this number, the more light can enter the binocular.

Light-gathering power is determined by the magnification factor, the lens diameter, and the quality of the material used to produce the lens. A binocular's lens can be compared to a water pipe. The wider it is, the more water will flow through it. It's the same way with light. The larger the lens, the more existing light can enter.

• Brightness & Clarity
• Important In Dim Light
• Larger Is Better When Movement Is Present

This specification is among the most important criteria for choosing the right binocular for a particular use. When holding a binocular at arm's length, you will see a small disc of light in each ocular lens. The size of these discs, called exit pupils, is determined by dividing the diameter of the lens, by the binocular's magnification power.

Example: A10x 42 binocular would have an exit pupil measure of 4.2 mm in diameter. Divide 42mm by 10 = 4.2mm Exit Pupil Diameter.

In bright light, the pupil of your eye dilates to only about 2.5 mm; this means your eye is capturing no more than 2.5 mm of light. Thus a LEICA compact 8 x 20 binocular with an exit pupil of 2.5 mm would be more than adequate in brightly lit objects.

Under darker conditions, your eye dilates wider open to 4, 5, or even 6 mm to allow more light in. At this level, details may escape the eye. In this situation,  a pair of binoculars with a larger exit pupil, such as:

• the LEICA 8 x 32 with a 4 mm exit pupil

• the LEICA 10 x 42 with 4.2 mm exit pupil

• or the LEICA 8 x 42 with 5.25 mm exit pupil

is essential.

Larger exit pupils are also important whenever binoculars cannot be held steady - on a rocking boat, for instance. A generous exit pupil gives a large area of view; this helps keep the object within the viewing circle of the binocular while you and/or your object moves.

• Important For Low Light Viewing

The twilight factor is a mathematical calculation used to compare the visual performance in low light viewing of different size binoculars.

It is very important to understand that only in combination with an accurately adjusted high-contrast optical system, and a large exit pupil, will a high twilight factor allow you to better distinguish details in poor lighting conditions. Therefore when selecting binoculars, the twilight factor should play a secondary role to the size of the exit pupil.

Example: The LEICA 7x 42 is an excellent binocular for low-light use due to its large exit pupil of 6 mm even though its twilight factor is smaller than in the LEICA 8 x 42 or 10 x 42 binocular.

• Width of View
• Important for Wide Area Viewing
• Speed Of Viewing - How Fast Is A Binocular

The field of view is the total area visible from a distance of 1,000 meters (3,280 ft).

Example: The LEICA 7x 42 has a very wide field of view of 140 m (460 ft).

The larger field of view, the faster and more convenient it is to observe a wide area or find and follow a moving object in the binocular.

TIP: As a simple rule of thumb: the lower the magnification, the greater the field of view.

With Leica internal focusing, the only part that is shifted is a lens in the interior of the binocular or spotting scope. Because nothing is shifted on exterior surfaces, neither air nor humidity are drawn in - a clear view is uniformly preserved, even in murky weather.

Central operation permits simultaneous focusing of both halves of the binocular. Furthermore the combination wheel patented by Leica allows convenient diopter compensation for both eyes, independently of one another. Once the diopter compensations have been set, their values can be read on a scale and they can be reset quickly when the binocular is used again at another time

The lenses in all LEICA TRINOVID BN and compact binoculars are treated with HDC™ optical coating (Highly Durable Coating). This innovative multiple coating is more scratch-resistant than conventional multiple coatings - a major advantage, especially for external lens surfaces.