Comparison Bushnell Falcon 10x50 vs Bushnell Powerview 10x50

The diameter of the area visible through binoculars / monoculars from a distance of 1 km — in other words, the largest distance between two points at which they can be seen simultaneously from this distance. It is also called "linear field of view". Along with the angular field of view (see below), this parameter characterizes the space covered by the optics; at the same time, it describes the capabilities of a particular model more clearly than data on viewing angles. Models with magnification adjustment (see above) usually indicate the maximum field of view — at the lowest magnification and the widest angle of view. This information is often supplemented by data on the minimum value.

The smallest distance to the observed object, at which it will be clearly visible through binoculars / monoculars. All such optical instruments were initially created for observing remote objects, therefore, not all of them are able to work at short distances. When choosing a model for this parameter, one should proceed from the expected observation conditions: ideally, the minimum focus distance should not be greater than the smallest possible distance to the observed object.

The offset is the distance between the eyepiece lens and the exit pupil of an optical instrument (see "Exit Pupil Diameter"). Optimum image quality is achieved when the exit pupil is projected directly into the observer's eye; so from a practical point of view, offset is the distance from the eye to the eyepiece lens that provides the best visibility and does not darken the edges (vignetting). A large offset is especially important if the binoculars / monoculars are planned to be used simultaneously with glasses — because in such cases it is not possible to bring the eyepiece close to the eye.

The method of aiming the optics of binoculars (see "Type") for sharpness.

— Central. In accordance with the name, focus in this case is carried out using a regulator (usually a rotary handwheel) located in the central part of the binoculars, between the halves. When such a flywheel is turned, both optical systems are adjusted simultaneously — this is convenient, because. allows you to quickly reconfigure the binoculars for different distances. On the other hand, such models are more complex in design than separate ones, have more weight and less reliability.

— Separate. In models with this type of focus, each eyepiece is adjusted separately. This is not as convenient as the central control, but it allows you to reduce the weight, dimensions and price of binoculars, and also facilitates the creation of "protected" devices.

— Automatic. The name in this case is not entirely true: we are not talking about automatic adjustment of optics, but about a fixed focus. Such binoculars do not require focus during use — they allow you to clearly see all objects in the range from the minimum focus distance to infinity, and the observer's eye itself performs the necessary adjustment (similar to what happens when viewing objects at different distances with the naked eye). Models of this type are very convenient for observing on the move, especially when th...e distance to the observed object is constantly changing, as well as in situations where the exact location of the appearance of this object is unknown — they allow you to "target" as quickly as possible and without unnecessary movements. As a result, autofocus is considered optimal for watching sports, wildlife, and the like. The main disadvantage of autofocus can be called the fact that it noticeably tyres the eyes — especially when alternating between the naked eye and the use of binoculars.

The presence in the design of the binoculars / monocular socket for attaching an adapter for a tripod(the adapter itself is not included in the kit, unless otherwise indicated). This feature is especially important for high magnification models (see above): they are usually heavy, making it difficult to hold stable in your hands, and at high magnification, even slight shaking can make observation impossible. In addition, mounting on a tripod is convenient for constant observation of a certain place, and such observation does not always require high magnification. Therefore, even fairly small devices can have the possibility of attaching an adapter. The adapters themselves can be designed for different sizes of tripod mounts — this must be taken into account when choosing such a model.