Binoculars

Binoculars are a device that enters the telescope class which means an astronomical device used to magnify the object from a distance, increases the angular size and brightness of the object, but the function of the telescope is actually more in use, not just for the observation of the stars alone , But also used for purposes such as military and shipping. Binoculars of this type is also commonly called "Teropong Medan" (in Indonesia), there are also commonly called "Kiyker". With binoculars objects can be observed stereoscopic (three dimensional)

Binoculars come from the Latin, "bi" meaning two, and "oculus" meaning the eye. As the name implies, this tool has 2 visions / tubes that adjust the amount of our eyes. In it, this binocular has a prism that is used to "fold" the cross-light line so as to produce a shadow in the right direction. With this binocular, the observed objects will be real and will not be reversed.

How binocular lenses work?

Lens Composition

1. Binocular with Erecting Lenses

(Visualization Erecting Lens) 

Source: en.wikipedia.org

This type of binocular can produce zoomed-in / zoom-out as desired, without having to replace eyepiece first. The arrangement for these lenses is Objectif Lens - Erectic Lens - Prism - Eyepiece / Oculer Lens. Erecting Lens position can be shifted, the further position of Erectic Lens from Objectif Lens then the visualization of the observed objects the greater, and vice versa
.
2. Porro Prism Binocular

(Porro Prism Visualization) 

Source: en.wikipedia.org

This type of binoculars has 2 prisms that serve to invert the shadow, the first prism after the objective lens serves to invert the shadow vertically, and the second lens serves to invert the image horizontally. The order is: Objectif Lens - Double Porro Prism - Eyepiece / Oculer Lens.

(Binocular with Porro Prism) 

Source: en.wikipedia.org

This Porro prism produces perfect reflection and refinement. One form of this prism is a 45 ° angled angle, this bracket is used as a double reflector. This prism reverses only one direction using two prisms enforced with each other can be held two-way reversal.

C. Roof Prism Binocular

(Roof Prism Visualization) 

Source: en.wikipedia.org

This type of binoculars has only one prism, and its properties directly invert the shadow horizontally and vertically so that the resulting image is real. This type of binocular physically has a straight appearance because it uses Roof-Prism type prism. The order is: Objective Lens - Roof Prism - Eyepiece / Oculer Lens

(Binocular with Roof Prism) 

Source: en.wikipedia.org

Focuser Position

1. Independent Focus,
Each binocular tube has its own focus regulator. So in the focusing phase just by adjusting the focuser of each binocular tube.

(Binocular with Independent Focus) 

Source: thebinocularshop.com

2. Central focus
Two tubes have only one focuser, but this type of binoculars in one tube usually have a special focuser, this special focuser is required for anisometropic patients

(Binocular with Central Focus) 

Source: 365astronomy.com

Types of Objective Lenses

The outer surface of this objective lens is a protective layer which is usually called a coating. The function of this coating is various, such as anti-reflection, ultra violet filter, light transmition and others. Among the common coatings used in some binoculars are:

1. Red Coating (Ultra Violet Filter)
The red color is dominated for protection in maximum lighting conditions. Binoculars with red coating colors are very well used for daylight in bright light conditions, because they can reduce almost 1/3 light, especially UV light, eg in the desert or hotspot field areas.

2. Blue Coating (Anti Reflection)
The blue color in binocular coating is the most we encounter, blue is the basic coating type, because the standardization of the lens usually must have anti-reflection for each blink of the eye, or reflex light when aiming the target does not make the head become dizzy. Binocular with blue coating is very well used for various conditions, both day and night.

3. Green Coating (Light Transmition)
The green color in the binocular lens is usually a light transmition type of amber stone that is able to drain light on all parts of the image of the captured object lens. Coating type of light transmition is suitable for use in low lighting conditions, eg at dusk or in a dimly lit (not dark without light) so it looks brighter.

4. Multi Coating (Multi Filter)
Not infrequently there are also several other colors, in addition to green, red and blue, such as purple, orange, and others, the color is the result of a combination of multiple coatings combined to benefit from multiple filters.

Types of Mounting

Until now there are no telescope manufacturers that make a special mounting binocular based on semi-automatic (motoric) and automatic (robotic). There is only binocular based hand claps and manual mounting. If you want to use binoculars with automatic mounting or commonly known robotic mounting, can be combined with mounting binoculars with a little modification.

(Modification Celestron Nextar Mount with Orion BT70 Binocular)

Source: id.pinterest.com