For every nature enthusiast, a pair of binoculars is indeed a great help.

A binocular produces a larger size (magnified) image compared to the image produced by naked eye. This results in the object appearing closer that the actual physical distance. The bigger the image, the closer the object appears. Binoculars are specified as a combination of two figures e.g, 8X40 or 10 X 25 or 7X50 etc. The first figure (7, 8 10 or 20 etc ) describes the magnification ratio of the binocular. A binocular with 8 magnification will apparently shorten the distance of the object by 1/8 th of the actual distance. Thus, a bird 80 meters away seen through a binocular of magnification ratio of 8 will appear as if it is being seen just 10 meters away. The greater the magnification, more is the possibility of shake in the view. For magnification greater than 12, even human breathing brings a vibration to the view and the image looks shaky.

The second figure after the X mark shows the diameter (in mm) of the front lens (objective) of the binocular. The smaller the diameter, smaller is the size of the binocular and lesser is the light gathering capability. Bigger objective diameters are good for vision in lower light levels and provide a better color rendition and saturation to the image. The construction of a binocular involves a prism inside and based on the orientation of the prism, two types are available – poro-prism and roof prism. In case of roof prism, the objective and the eyepiece are in the same optical line whereas in case of poro-prism, they are aligned with an refractive offset. Ideally a magnification of 7 to 10 and an objective diameter of 30 to 50 mm is recommended to suit all needs in the field. Hence, combinations like 7X50, 8X40 or 10X50 are desirable, but avoid extreme side combination like 20X50, 16X80 or 12X25.