When looking through a binocular, the widest dimension of circular viewing area that you can see is described as the field of view. This is usually measured either in terms of linear metres at a 1000m range. As a general rule, the field of view will decrease as the magnification increases so a 12 power binocular will usually have a smaller field of view than a 7 power. Field of view, however, is also determined by optical design of the ocular lens (eyepiece) and rarely a sole function of the size of the objective lens. |
Wide-field binoculars, however, tend to be heavier and bulkier than binoculars with standard fields. Also, if you have too large a field (over 150m for instance) the object you want to observe may become lost amid the confusion of its surroundings. |
| For observing at close
quarters in deep woods, scanning the sky for birds or for picking up fast
moving objects such as rabbits, a wide field of view is desirable. |
Another problem is that people who need to wear eyeglasses when viewing will usually have difficulty seeing the complete field with wide-angle optics. Wide field binoculars are generally the most popular for nature observation but you should consider all these factors in your evaluation of this feature. |