Leica 10x42 BRF manual Optical quality

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Glossary For illustration purposes, the pictorial examples show strongly exaggerated effects of the various types of imaging errors or aberrations.

Optical quality

Contrast and resolving power Contrast is defined as the difference in brightness between light and dark areas of the image. The greater this difference, the higher the contrast. An image that is rich with contrast is subjectively perceived to be sharper and more brilliant. Resolving power is the extent to which an optical system is capable of reproducing the finest structures. The greater the resolving power, the better are the finest details rendered, even under difficult light conditions. Pictorial examples : In optimally rendered images (left), both contrast and resolution are high. If the contrast is too low, the image is flat (center). If the resolution is too low, the image is unsharp, one can no longer discern details in the feathers (right).

Reflections and flare When light rays are reflected by lens surfaces and/or structural components or scattered by lens mounts, they arrive at a location in the image that is different from the one where they are intended to arrive. Undesired reflections and light areas that can degrade the image significantly and that can impair the visual impression occur especially when the sun shines directly into the front lens. To prevent reflections and flare caused by stray light rays, Leica takes numerous dedicated steps. To begin with, the shapes of lens surfaces, mounting components and light traps are already optimized during the design stage so that no extremely disturbing effects are to be expected. Furthermore, a significant reduction in reflections and stray light components is achieved by means of special coatings of lens elements (vapor deposition of special reflection- reducing layers) and by the matte black finish of internal mechanical components.

Depth of field Depth of field is the distance between the nearest and the furthest away objects that can still be perceived as being sharp at a given focus setting without the need for refocusing. The depth of field is dependent upon the magnification of a binocular or spotting scope. The lower the magnification, the greater the depth of field. Therefore, if one wishes to see several objects at different distances but with the same sharpness (as illustrated on the left), one would give preference to a binocular with a 7 x or 8 x magnification, which would also have great advantages for observation at twilight or in poor light conditions, because one would not have keep refocusing to maintain a sharp image. The greater the magnifica- tion, the smaller the depth of field. Greater magnifications are advantageous when one wishes to discern more details or smaller objects, as illustrated on the right.

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Imaging errors (aberrations) In order for a sharp image to be created, light from a point on the subject must re-converge as a point in the picture. As a rule, a single lens element is not adequate for this purpose, because it has inherent deviations (imaging errors or aberrations), that are described a follows : By selecting appropriate types of optical glass and lens coatings, and by combining the right lens elements and by converting the computed lens design into reality a accurately as possible, Leica suc- ceeds in keeping all the residual aberrations at a very low level. To that end all phases, from optical design to fabrication, are optimized for the always highest possible imaging quality.

Aperture errors – spherical aberration The closer to the edge light rays pass through a lens, the more they will tend to arrive away from the actual picture point. Because this effect becomes stronger as the front lens diameter increases, it is referred to as aperture error, also called spherical aberration. Aperture error causes a loss of sharpness and contrast in the image. In extreme cases, flare becomes noticeable – halos are formed around point sources of light, as illustrated in the pictorial example above.

Coma When coma is present, light rays will deviate to one side of their intended picture point. The picture point will gain a tail like a comet. This effect occurs more towards the edges of the picture and not in its center. Strong coma leads to a loss in sharpness and contrast, in extreme cases the coma tail becomes noticeable in point sources of light, as illustrated in the enlarged section of a picture of a star. This section was cropped from the left upper corner of the moon picture.

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Contents Leica Sport Optics Leica Digiscoping Page Yellow Wagtail / Motacilla flava Spanish Imperial Eagle / Tringa totanus Leica Camera Inc has been One of these entities American Birding Association ABA, USA Duovid class Two binoculars in one Leica Duovid 10 +15 x Leica Duovid 8 +12 x Leica Duovid 8 +12 x Leica Duovid 8 +12 x 42 the most flexible 42 mm binocularsLeica Duovid 10 +15 x Black Order No Green Order No Duovid class Two binoculars in oneLeica Duovid 10 +15 x 50 the binocular-spotting scopes Ultravid class Binoculars for extreme demands Leica Ultravid 8 x 20 BL Leica Ultravid 12 x 50 BR Leica Ultravid 7 x 42 BR Leica Ultravid 8 x 50 BRLeica Ultravid 10 x 50 BR Leica Ultravid 12 x 50 BRLeica Ultravid 10 x 32 BR Leica Ultravid 8 x 42 BLLeica Ultravid 10 x 42 BL Leica Ultravid 8 x 32 BRLeica Ultravid 10 x 25 BL Leica Ultravid BR 25 mm the stars among the compactsLeica Ultravid 10 x 25 BR Leica Ultravid 8 x 20 BL Leica Ultravid 8 x 20 BRLeica Ultravid BR 42 mm the robust all-rounder Leica Ultravid BL 42 mm lightweight in a classic designUltravid class Binoculars for extreme demands Leica Ultravid BR 50 mm ready for any light conditions20 BL Order No Leica Ultravid BR 32 mm always with youTrinovid class Proven technology for Leica Trinovid 10 x 42 BN Leica Trinovid 8 x 20 BCA Leica Trinovid 10 x 32 BN Leica Trinovid 8 x 42 BNLeica Trinovid 10 x 42 BN Leica Trinovid 8 x 32 BNTrinovid class Proven technology for the ambitious viewer Leica Trinovid BCA 25 mm and 20 mm distinguished compact20 BCA Order No Leica Trinovid BN 32 mm the constant companionsTelevid class High-performance spotting scopes Leica Televid Leica APO-TELEVID Light conditions Leica Televid 77 ensures the viewerGreat detail recognition, even under the worst Scott Roederer, birder and author, USA Order No WW/16 WW/26 x WW WW/32 x WW 20-60 x/16-48 Order NoLeica APO-TELEVID 62 true color rendition in a compact form Vertical or horizontal format Leica Digital AdapterRangefinder class Pure precision monocular Leica Rangemaster 900 scan Leica Geovid 8 x 42 BRF Leica Geovid 10 x 42 BRF Leica Geovid 8 x 56 BRFLeica Geovid 8 x 42 BRF Leica Rangemaster 1200 scan Leica Rangemaster 1200 and 900 scan the small big helpersLeica Rangemaster 900 scan Leica Geovid 56 BRF Observing and rangefinding Leica Geovid BRF next generation binocular with rangefinderGreat White Pelican / Pelecanus onocrotalus Technical Data Eyepieces for eyeglass 12 x 50 BRMagnification Front lens diameter Exit pupil Twilight factorArmored, black Delivery scope 10 x 32 BR10 x 25 BR/BL 20 BR/BL 10 x 42 BNField of view 10 x 32 BN10 x 25 BCA 20 BCA Spotting scope Angled viewing Delivery ScopeEyepiece for Filter thread Dimensions W x H x DStraight viewing Focal length of the lensBattery lifetime Objective angle of view Close focusing distanceMeasuring mode Power supplyOrder No Neoprene carrying strap, contoured Technical Data Very useful binocular equipmentFloating carrying strap, orange Order No Ever-ready-case for Televid 77 Angled view Tripod adapter for binocularsOrder No Carrying case for Televid Order No Ever-ready-case for TelevidExample Leica Trinovid 10 x 42 BN Technical binocular termsOptical quality Glossary Color errors chromatic aberrations Every image-formingLens with Leica HDC multi layer coating Lens without coatingLeica rangefinder technology with a press of the button
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