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Aspherical Lenses
Binoculars with aspherical lenses yield a crystal clear image with excellent edge sharpness. Due to a special manufacturing process, the lenses concentrate all incoming light at the focal point, leading to a brilliant, true-to-life image
Compact Binoculars
See "Design".
Design
Compact Binoculars
The very small, light binoculars of the Compact series are especially suitable for daylight use. They make ideal companions for walking tours, day trips and excursions. They also serve well as practical backup binoculars in hunting: When folded, they stow easily away in an outer pocket and are ready to hand when needed.
Porro Prism Binoculars
The fascination of three-dimensional representation: The classically wide design of porro prism binoculars allows for clear perception of spatial distances even at close range. The optical systems were adjusted with great care to ensure an impressively bright, high-contrast and true-to-detail image - ideal prerequisites for the observation of wildlife and the surrounding area, even in the poor light conditions of an early morning or late evening.
Roof Prism Binoculars
The technologically very advanced and sophisticated roof prism binoculars stand out due to their slender shape, facilitated by the vertical alignment of the prisms. This design requires an accurately computed optical system. The result: An image absolutely true to nature.
Diopter Control
Diopter control compensates for the users' differences in vision so that the image can be brought into focus.
Exit Pupil
The exit pupil indicates the amount of light that reaches the human eye through the optical system and therefore strongly determines image brightness. The exit pupil is calculated by dividing the objective lens diameter by the magnification. The LUGER ST 7x50, for example, has an exit pupil of 7.14 mm (50 : 7= 7.14).
To achieve optimum image brightness, the binoculars' or spotting scope's exit pupil should be at least the same size as the user's pupil - which varies with age and light conditions at the time of observation. A young person, for example, has an exit pupil of about 4 mm during daytime and 7 mm at night, whereas an older person shows an exit pupil of about 3 mm and 4 mm respectively. Generally speaking the binoculars' or spotting scope's exit pupil can be relatively small in favourable light conditions - e.g. sunshine - but should be larger in poor light conditions - e.g. dawn or dusk.
Field of View
When looking through binoculars or spotting scopes, a circular image appears. The width of this image is referred to as the "field of view". For binoculars and spotting scopes the field of view is being measured for m/1000m. For Riflescopes it is measured by m/100m. The corresponding figure indicates the width of the area visible at a distance of 1000 m (100 m). The LUGER SW 8x40 binoculars cover 140 m of an area 1000 m away. The higher the magnification, the smaller the field of view. Special wide angle oculars yield larger fields of view despite high magnification.
