Outdoor binoculars are used outside to look at objects or views in the distance. An ideal outdoor telescope should have the following features: nitrogen-filled waterproofing, rubber outfitting, proper multiple and aperture, portability and ease of use, of course excellent optical quality is the least of them.
The working principle of optical indicator:
From some of the fundamental optical indicators of the telescope, there are separate definitions for outdoor sports,
Resolution: this is the first indicator that poor resolution mirrors can help you view crocodiles as tree trunks.
Exit pupil: you can simply divide the number by the aperture, the larger the number, the better for catching your prey under dark light.
Color reduction: partials exist on many telescopes, and general observation may be less stringent, but if it's used for wild bird-watching, you can't accurately describe the color of a bird's feathers.
Film plating: fake Russian binoculars with street-shining red film are a real rape of the eye, causing a sharp loss of light, color reduction problems and a tendency to cause unpleasant glare, and the best film can make you almost invisible.
Waterproof: in order to prevent the infiltration of rain or cold weather in lens caused by bad fog even long time use the entry of dust, nitrogen filled waterproof can fundamentally solve the problem, it doesn't matter even throw it into the water, and some not nitrogen filling sealing actual military telescope is also very good, as long as it doesn't soak into the water, the general and sand can be dealt with.
Shock absorption: for long-term use in the field, accidental collision is inevitable. For telescopes with poor materials for design and construction, optical damage such as axial weight shadow can easily be caused. Therefore, a thick layer of rubber outside the mirror is a good protective measure, which can improve the hand feeling and grip besides shock absorption.
Magnification: in the outdoors, the telescope is generally used to observe the terrain, enjoy the scenery, watch birds and animals, and is suitable to be used in multiples of 6-8, considering the requirements of earthquake and optics. As for caliber, 20-40mm is ideal according to the focus and requirements of use.
Portable: outdoor sports itself requires individuals to carry a lot of equipment and supplies, in every gram weight affect the physical conditions, one-sided pursuit of optical performance and ignore the volume and the weight is not realistic, in a sense, to say the weight and the optical properties of the contradictions are irreconcilable, the mirror of the large diameter high brightness, inevitably lead to the rapid increase of the overall weight, so can only according to the requirement of the personal hobbies, the weight and make a satisfactory compromise between optical requirements. Roof-prism telescopes are relatively small in size and weight, easy to carry, and expensive to manufacture.
Techniques of choose and buy
For different people, the choice of outdoor telescope will be different due to the different emphasis of the requirements. There is no uniform rule. Choosing a suitable outdoor telescope according to your requirements and preferences will bring great pleasure to your outdoor activities.
For most, the most telescope manufacturers of outdoor telescope can choose, general specifications in the magnification is more than 7 times, less than 12 times, 30 mm to 56 mm diameter in between are also accepted, it is best to Paul or roof prism design, nitrogen filled waterproof glue, superhard multilayer coating, field of view, focusing his eyes, 1000 g in weight control.