Calculate and explain the exit pupil of binoculars

Exit pupil binoculars and riflescopes - meaning and calculation

For the See in the TwilightFor night glasses, which are ideal for sitting game and as sow glasses, the light intensity is the most important feature. " More info (twilight vision) is of great importance, in addition to the Twilight numberalso the Binoculars Exit pupil on EyepieceThe eyepiece is the lens group of an optical system that faces the eye. The eyepieces consist of several separate lenses - achromats (3-6 individual lenses).  " More info of the binoculars. The following applies: the larger the diameter of the exit pupil, the greater the theoretical image brightness in the binoculars. EyeThe retina of our eyes has two different types of sensory cells or receptors, the cones (for day vision) and the rods (for night vision). " More info.

Formula Exit pupil Calculate with binoculars

To determine the binoculars exit pupil, calculate the quotient of binoculars EnlargementThe magnification of a binocular model is perhaps the most misunderstood feature. High magnification can be useful! " More info and Lens diameterThe larger the lens diameter, the more light can be absorbed by the lens of the optical system. Glass purity plays a major role. " More info: With a Binoculars 8×56 is thus calculated as Exit pupil of 7 mm diameter and usually corresponds to the maximum opening of the pupil or the visual fossa of a healthy human eye.

 

Exit pupil and binoculars in old age

As the exit pupil can only be calculated using a mathematical formula, the exit pupil of an optic does not allow any conclusions to be drawn about the quality of binoculars or target optics.

However, it can in old age occur that the maximum pupil dilation of your eyes decreases to 5-6 mm and therefore the light output of the 7mm exit pupil of 8×56 binoculars can no longer be absorbed 100%ig by the eye.

The binocular exit pupil on the eyepiece of other night glasses such as the DDoptics Nachtalken HDX 10×60 is 6 mm due to the exit pupil calculation. For this reason, older hunters often use Night glasses 10×60 or also Night glasses 10×56 preferred as hunting binoculars for night hunting.

Subjective perception of twilight performance

To achieve the highest possible Twilight performanceIn order to be able to recognise details over long distances even in twilight, binoculars with high magnification and corresponding twilight performance (e.g. 10x56 or 8x56) are recommended. " More info to make optimum use of the optics, the Pupils of the eye and the exit pupil of the binoculars are the same size be.

As the maximum pupil opening can vary from person to person and with ageIt is also understandable that the light intensity of the same binoculars can be subjectively perceived differently by everyone and in every situation.

Binoculars with an exit pupil of less than 4 mm in diameter have a low twilight performance. In daylight, the eye pupil has a size of 1.5 - 2 mm. With a large exit pupil of the binocular eyepiece you don't get so easily caught in a stronger hand restlessness (e.g. when observing from a boat). outside the diameter of the exit pupil of the binoculars.

Extract Binoculars with different exit pupils in the DDoptics optics shop