Archive for the ‘birding’ tag
Binoculars Light Gathering
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All you need to know about bird binoculars
Bird watching could be a very exciting experience, leaving long lasting memories and unforgettable moments for all nature lovers. For this reason why you need to be careful, when purchase a pair of binoculars. The quality is very important - it is always a pleasure to be able to identify bird species and its specific coloration patterns or see clearly different parts of the body. Blurred lenses or very narrow field of view can cause a failure and you won`t fully enjoy your favorite hobby. Actually this can be very frustrating. Now we are going to discuss the basic criteria that should be taken into consideration when choosing, so that will spare you moments of hesitation and negative emotions.
Light collection
The main criteria is the possibility of gathering a maximum amount of light. Very often we will have to watch birds in the early morning or in the end of the day. In these situations there is a little light and we need a maximum quantity of it to catch the object with a high-grade image. Of course, this is achieved with larger lenses of the objective. Lenses coating has a great importance when it comes to observing in low light conditions. The most recommended lenses are Fully Multi-Coated. They allow the highest level of light transmission and this provides you with a clear, sharp and bright image.
Magnification
Admittedly, the magnification of binocular is not forgotten. Everyone wants a maximum magnification to be able to see more details, but there are some facts that we should not forget. At high magnification, we get pretty narrow field of view. This will hinder us in finding the object and also monitoring its movement. Birds fly fast, so is good to have a wider field of view. It is accepted, for birdwatching binoculars, the field of view to be not less than 300ft/1000 yards.
Optimum version, of gathering enough amount of light and good magnification, is binocular with size 8x40 mm or 8x42 mm.
Exit pupil
The exit pupil, measured in millimeters, refers to the diameter of the shaft of light that exits each eyepiece and reaches the pupils of your eyes. Calculate this number by dividing the diameter of the objective lenses by the magnification. A 7 x 35 model, for example, has an exit pupil of 5 mm (35 divided by 7). In other words, a bigger exit pupil means more light reaches your eyes, producing a brighter image. A large exit pupil also makes it easier to maintain a full image if your hands move or shake. Keep in mind that your eyes' pupil size varies from approximately 2.5 mm in bright light to 7 mm in low light. For viewing at dusk or dawn, look for binoculars with an exit pupil of 4 mm or more.
Focusing system
Another important factor is the speed at which you can focus the binocular. The reason is that birds are fast moving and they quickly change the distance from us. Binoculars with good focusing mechanism can go from close focus to infinity in one full turn of the focus ring, but for focusing at close distance, this is a problem. So some manufacturers offer as option focusing with variable speed of rotation. When the ring rotates rapidly, the focus also changes rapidly. A fine tuning can be done at lower speed of rotation. However, that needs some practice. What also matters is ring position, it should be easy to reach. Convenient option is binocular with auto focus.
Waterproof
Regarding to waterproof, binocular is good to be at least water resistant, that would keep it from light rain. But it is obligatory to be fogproof. This prevents from internal fogging, caused by high humidity, fog and temperature extremes.
Weight
Weight does matter and it is not something that you can easily ignore. We have the binoculars with us all day long, perhaps we need to climb or walk on uneven terrain. So, it is better to think of well balanced binoculars, comfortable to carry around and of course a strap, which can be very useful both for your neck and for your binoculars safety.
About the Author
The author - Galin Ganev, is founder of http://www.binocularssell.com. On this website you can find varied articles of binoculars, telescopes and their accessories. There is useful information about how to choose optical devices, their using and keeping.