Night Vision

Night Vision
The bear and boar hunt in Russia usually takes place at night. Large calibre weapon and accurate round together with the reliable and high-aperture optics are the paramount factors that determine the hunt effectiveness and safety for the hunter.

Numerous years of my personal experiences with night vision riflescopes from Dedal-NV definitely confirm their leading positions on this competitive market.

The thermal imaging gear has emerged recently as an alternative to the night vision. That is right, in complicated weather conditions, thermals do deliver certain advantages in game searching. But these devices would never identify your target with confidence at long distances, with dense vegetation on the background or if the object stands motionlessly in front of a heated rock. In the absence of a true mastery, these disadvantages decrease your chances for a successful shot, and if you make a mistake, may lead to an unpredictable and even tragic outcome.

Sometimes you would not want to shoot your game. A good hunting video may become the largest jewel in your collection of the best life impressions. All Dedal riflescopes can be easily attached to any video recording equipment. This is how I made top quality movies with wild beasts in their natural habitat.

I am very convinced personally, and so are other serious hunters, whom I know, that night vision riflescopes are crucially important for our successful hunting.

V. Rushailo,

About Night Vision

Among the light sources that create natural night illumination the most important are: the sunlight reflected from the Moon, starlight and gas luminance from the upper atmosphere layers. The Moon is the greatest contributor to night illumination. For example, the illuminance level at full moon constitutes 0.3 lux, while during a moonless yet starry night it is only about 0.002 lux. Not only the light intensity changes after sunset. The spectrum of the light shifts into the near infrared zone. Finally, not only natural illumination level but the contrast between the observed object and its background (green/dead grass, black soil, rocks, etc.) becomes crucially important for detection and identification of the object.

As it becomes clear from the curves shown in Fig. 1, all objects of interest are best illuminated and have the best contrast with the background in the near-infrared zone, while the human eye has maximum sensitivity in the yellow-green zone. Therefore, the main challenge of a night vision device is transformation and multiple amplification of light in the near-infrared zone into a spectrum, which is more adapted for the human eye.

The operational principle of NVD is based on the transformation of the incident light into electron flow inside a special device called Image Intensifier Tube (IIT). The electron flow becomes amplified thousands of times inside the tube and then is transformed back to visible light photons on the internal display. By design and historically, all IIT are divided into three groups, which are called “generations”. All tube generations share in general a common architecture and work under some natural illumination or with the help of an external IR illuminator. In real deep darkness night vision devices are helpless. The IIT of the first generation are the weakest ones and used in amateur devices only. Their amplification coefficient is below 1000.

100% 80 60 40 20 0,3 0,4 0,5 0,6 0,7 0,8 0,9 λ, μm Eye at night Eye by day Green grass Withered grass Star Light Moon Light
Optical scheme of the riflescope
150 S, mA/W 120 90 60 30 0,3 0,4 0,5 0,6 0,7 0,8 0,9 λ, μm Gen.2+ Gen.3

As a result, the next step in night vision evolution was made with the introduction of a microchannel plate inside the tube. This element accelerates and multiplies electrons achieving overall amplification above 10,000. This design is shown in Fig. 2. It is known now as Generation 2 and 2+. The main disadvantage of Gen. 2 IIT is its spectral curve. As shown in Fig.3, the spectral response of Gen. 2 tubes is relatively wide, and it lacks sensitivity in the near IR zone. The most up to date devices belong to Generation 3. They are distinguished by the photocathode material (GaAs). This material provides maximum sensitivity in the near infrared range and the highest overall (integral) sensitivity across the whole curve. This benefit allows covert (without IR illumination) usage of Gen. 3 NVD in the deepest darkness.

Dedal-NV Night Vision Goggles are designated for orientation and observation in darkness, The Goggles can be equipped with interchangeable objective lenses with various magnification (1× / 3× / 4× / 6× / 10×). The interpupillary adjustment system allows individual adjustment to the observer's eyes, thus providing extensive usage without fatiguability.
Dedal-NV Night Vision Monoculars are very compact and can be either fixed with the head straps or used with interchangeable magnification objectives. For shooting night photos and videos, the Monocular can be fixed in front of your imaging/recording equipment. Also, the Monocular can be fixed behind a daytime riflescope thus turning it into a day/night aiming system.
Dedal's Night Vision Riflescopes provide optimal weapon balancing and are distinguished by high optical power, compactness, lightweight, hermetic sealing with nitrogen purging, and protection against dust and moisture (IP67). The Riflescopes operate in a wide temperature range from – 40°С to + 50°С, withstand high calibre recoil (.338LM, .50BMG) with confidence and can be easily adapted to practically any rifle.
In night time, light-gathering power of even the best quality daytime riflescope becomes insufficient for successful aiming. You would need a special device called Clip-on Attachment, which is compatible with your daytime riflescope and is mounted in front of it. Dedal's Night Vision Clip-on Attachments retain the mean impact point of the daytime scope while installation/removal from the rifle. They preserve all daytime riflescope’s tactical capabilities such as variable optical magnification, ballistic corrections, exit pupil position and low position of the optical axis above the barrel.
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