Articles

All you want to know about binoculars but you are ashamed of asking

4. Important front lens

Actually the most important part of binoculars is a good front lens. The amount of gathered light, resolution and image quality depends on this lens size, its construction and build quality.

Gathering light depend on objective lens area. Considering light receiving by our eye and then using binoculars with objective lens 50mm we increase this light 50 times. That’s why 56mm binoculars even though they are only 12% greater than 50mm binoculars, they gather up to 25 % more light.

Objective lens size is of great importance in achieved resolution. The greater lens is used, the better resolution is gained.

Of course you can say why not to build greater lenses just to gather more light. Unfortunately size and weight is the main restriction in this case. Besides the greater lens is implied, the more noticeable optical aberractions are.

Information given above very clearly show that the lens is the most important part of binoculars. Image which is gained by a lens is magnified by eyepiece lens. So if this image is bad quality, its magnification will cause more optic defects. So there is no reason to use monstrously great magnification. A lens diameter given in millimetres more or less equals to maximum possible magnification. Considering an instrument with 50 mm lens we shouldn’t expect good quality image for more than 50x magnifications. Don’t let fob yourself off with extremely great magnification up to even 80x found in small zoom binoculars at many online auctions.

In addition using binoculars we can’t avoid shaking hand when holding binoculars. 12x magnification is considered as a maximum comfortable and useful magnification when we are holding binoculars in hands. In case of greater than 15x magnifications we should obligatorily use a tripod. Because of that it is not advisable to buy zoom type binos like e.g. 15-80x70 and using them without good tripod.