The Right Binoculars

In general, the right binoculars are the biggest and most expensive binoculars whose exit pupils fit your fully dilated pupils, and whose magnification does not exceed your ability to steady them under normal viewing conditions of mild to moderate windiness, mild fatique and taking into consideration the holdability of the optics. Now, in the case of a young eye, under the age of 35, a 7mm or larger exit pupil will provide the greatest lowlight performance as well as user comfort. However, should such a viewer feel that most of his or her viewing will be conducted during the day and in relatively open spaces such as across fields or on mountains, a rational choice may well be to forego the advantages of a 7mm+ exit pupil in favor of greater magnification up to one's ability to steady that magnification. Thus, for a 30 year old in strong physical condition with the desire to pack the most formidable instrument for daylight useage, the choice may be a 12x50+mm binocular such as Leica 12x50 or Leica Duovid 10+15x50, or even Swarovski 15x56 without a tripod mind you! But, another 30 year old who is planning a visit to the Amazon Basin will be better served by 8x50+mm binoculars such as Leica 8x50 or Zeiss 8x56, or Swarovski 8x56, because they will allow him or her to see the most under the worst lighting conditions as may occur at the bottom of a rainforest near dawn or dusk. But if, on the other hand a 55 year old is visiting Amazonia, it is preferable for this person -whose pupils surely cannot dilate beyond about 5mm- to discover just how much magnification and weight he or she can handle. For such an individual, provided he or she is strong and steady handed, a 12x56 Zeiss (no longer made but perhaps findable) is ideal. Failing that, a Leica Duovid 10+15x50 is good as is a 12x50 Leica, a 10x50 Leica or Swarovski, or even a 15x56 Swarovski provided that configuration is tested beforehand. Although 56mm binoculars are heavy, note that they have very long optical tubes which entails a greater moment of inertia, hence greater inherent stability. Thus, a strong 55 year old will find a 12x56 equally stable as a 10x42 because it is longer. Lastly, we come to another class of users and conditions. Suppose the user is not particularly strong. In this case, the right fit has to be limited to a weight with which the user can cope: probably 30 ounces. If the user decides that even this is far too heavy, he or she may unfortunately have to accept the fact that they will NOT be getting the best binoculars. For example, even the finest 30mm or smaller binoculars in the world are inferior to a decent 42mm binocular, and will be completely incinerated across the board by perhaps even the most modest 50mm binoculars from a good manufacturer such as Zeiss or Leica. So in the 30 ounce area, you basically have 7 or 8x42s. But 10x42s may be appropriate for daylight useage, and you can't beat the celebrated Zeiss Classic 10x40s. If you're weaker than newborn babe or are climbing 8000 meter mountains, you may be stuck with 32mm binoculars which sort of work some of the time. But if you opt to go with compacts such as 10x25, you must resign yourself to the fact that no matter what you spend, you won't be getting a trully quality image under any circumstances whatsoever. Even the worst Chinese 42mm porro prisms are better than the best German 10x25s. And that's a fact. In general, aperture (objective lens size) IS king. One of the premium binoculars is only made in 32mm and 42mm and has very large prisms for its aperture. A wise choice would be to ask oneself: "shouldn't I just buy 50mm Leicas instead?" They aren't much larger in fact, and they will certainly outdo ANY 42mm binoculars that have been or can be made in the foreseable future. Sometimes compactness is worth as much or more than weight. It is impossible to beat Leica for durability and compactness. However, Swarovski has the edge in depth of field, and Zeiss is the sharpest PERIOD. These statements are general and vary with the period of manufacture, being most accurate NOW. In the remote past, Zeiss was categorically superior to ALL other binoculars in ALL ways. This has changed significantly, but Zeiss is still the sharpest. On the other hand, Leica has the sharpest edges, and Swarovski has the best depth of field, so much so that you may never touch the diopter wheel as long as you own them. So, to recap: which binoculars are OPTICALLY the best for you? The biggest to start with. Then, the biggest exit pupil that will fit your eyes. To measure your exit pupils, do the following. 1) draw a 5mm circle and cut it out, then paste it to your cheekbone under one eye. 2) enter a room with a mirror. 3) Set up a camera to focus SHARPLY on your image in the mirror 4) turn off the lights not moving from your postion and wait 10 minutes for your eyes to dilate to the maximum. 5), take a flash photograph of your eye as reflected in the mirror, making sure that your camera has the power and quality to do this in an instant (<0.01 seconds is best). 6) Study the photograph and compare your pupil's diameter with that of the 5mm drawn circle to estimate it's size. 7) when selecting a binocular, remember that the exit pupil is always equal to Aperture/Magnification. Thus, 10x50s have 50/10 mm exit pupils or 5mm exit pupils. So if your eyes were exactly 5mm, then this would make a fine choice, but no better than 12x56 if you can hold it steady. One small consideration: if your eyes are particularly close together, you may want to inquire about the minimum interpupillary distance of the binoculars you are contemplating. And know that, in this rare case, you may be restricted to 1) small binoculars, or 2) porro-prism binoculars. Porro prism binoculars are the binoculars with the wide-body configuration and are incredibly sharp for their price, but usually suffer from ghost images and stray light because they have not been designed to the most modern specs as only the intense and capital rich R&D operations of the premium European manufacturers, namely Zeiss, Leica and Swarovski, can guarantee. Last but not least, some people may find that image stabilized binoculars are the right choice for them. Basically, image stabilized binoculars are optically inferior across the board. However, magnification IS the single most limiting number on what you can actually SEE with binoculars in good light, just as aperture is the limiter of QUALITY. I am always available to answer additional questions about sports optics. Feel free to contact me at 718-578-5231 any time of day or night -I don't sleep by the phone!