Astronomical Binoculars - Night Watching Made Easy
When stargazing, progress from the naked eye to binoculars makes you realize that astronomical binoculars offer the astronomer or the stargazer a different level of perception and optics. The variety of binocular brands and models available in today's market can make selection of your astronomical binocular or binocular telescope a daunting prospect.
When stargazing, in general, the larger your observation binoculars are, the more you see. However, larger binoculars are heavier, may require a mount and are more expensive. Hence, the right binoculars for astronomical applications depend on the intended use of the astronomy binoculars, and your choice can be guided by the following factors:
- Size of objective lenses - Each increase in size of the optical lenses gives a proportionate increase in light gathering, price, weight and size.
- Magnification - Magnification, the degree to which the object being viewed is enlarged, is co-determined by the field of view of the binocular. Magnification in binoculars for astronomy can range from 6 power, giving wide field views of up to 10 degrees, to 20 power, which would require tripod mounting of the binocular.
- Prism - Binocular prisms are made of two types of glass - Bak4 glass prisms allow all light rays from the edge of the field to be fully reflected and give a brighter and sharper image than Bk7 prisms. Porro prisms are generally less expensive than roof prisms and are preferred in binoculars by stargazers.
- Focus Type - Both IF (individual eyepiece focus) and CF (center-focus) are used in astronomy binoculars, but IF eyepieces are much more rugged and weatherproof.
- Waterproofing is not a pre-requisite, but as the astronomy binocular is exposed to dew and moisture; a waterproof binocular would be preferred.
- Lens coatings are an important aspect of binocularity in astronomy as they result in greater image sharpness and contrast.