A fully multilayer coated lens for a high-end telescope
Anti-Reflection Coating Supplier shares that now with the development of the society, everyone is a new record high on quality of life, now often go to travel, adventure, adventure, etc. This kind of activity, then carry a telescope is essential, and high-end binoculars is military, navigation, aviation and other industries indispensable thing, so, today the Anti-Reflection Coating Supplier would like to share us some basic knowledge, high-end binoculars whole multi-layer plating high-end binoculars lens is what kind of "secret"?
The optical components of the telescope, supplied by Customized Optical Components Manufacturer, also known as objective, eyepiece and prism, are coated to reduce optical loss and reflection caused by reflection, and to increase the transmission rate and contrast of light.
A limitation of reflected light in binoculars is that when light hits ordinary glass, 4-5% of the light is reflected from the glass surface (the glass itself absorbs some of the light as it passes through). A telescope with an average of 10 to 16 glass surfaces may lose 50 percent or more of the initial amount of light that hits the objective lens, or worse, all the reflected light that bounces off the inside of the telescope produces a shimmering and ghosting image.
The glass (filter) is coated with a very thin vacuum coating, which has a certain chemical composition (usually magnesium difluoride - MgF2), and the amount of reflected light on each glass surface is reduced to 0.25-- 0.5%, and the transmission of light and contrast are better than ordinary coating.
The thickness and density of coating layer should be absolutely standard, otherwise there will be unexpected reflection and other problems.
So how to distinguish the coating type?
Coating is one of the most confounding words, and in many cases the description of the telescope is most misleading.
Optical coating :(C) -- means that only one or more lens surfaces already have an anti-reflection film;
Fully coated :(FC) - this means that all glass surfaces in contact with air have been coated. (in most cases this means less.
Multilayer coating :(MC) -- one or more lens surfaces have been coated with multilayer coating. Some lens surfaces may be coated with monolayer or without coating at all
Full multilayer coating :(FMC) - all surfaces in contact with air have multilayer coating.
If you have the money, buy a fully multilayered telescope, because it can transmit more light and image more clearly. That's why a fully multilayered telescope costs more than a normal telescope
The little knowledge
You will see 7°, 8°... This number, this is the Angle of view that the telescope is looking at when you know the angular field, you think of the line field, you multiply the angular field by 52.5, when actually 1° is 52.365 feet @1000 yards.