The name itself suggests the purpose of pocket binoculars which is to be able to store and carry them around in your pockets. They are small, lightweight and very easy to hold in hands and carry around the neck. They’re perfect for birdwatching, traveling, safari or any outdoor observations (sports events or concerts). To ensure smaller dimensions and compactness they usually have roof prism system that offers better optical technology and binoculars are therefore sharper. Other occurring prism system is reverse Porro. Due to their smaller size the lens diameters in pocket binoculars are between 20 and 26 mm and the magnification is normally between 8x and 12x. With most pocket binoculars the bridge folds at two different places to bring both optical barrels together – that way they’re really compact, suitable to store in pockets and offer closer interpupillary distance. However, in some rare cases the bridge folds in only one place which makes them less compact. Because they are intended to be used outside they are usually waterproof and fog-proof to prevent any inside fogging when exposing your binoculars to extreme temperature fluctuations. To keep their compactness, they have short eye relief which makes them less suitable for eyeglass wearers. In comparison with compact binoculars, pocket binoculars have smaller magnifications and smaller objective lenses. But in comparison with opera glasses, pocket binoculars are bigger and have bigger magnifications. However, due to their smaller size they may not be the most comfortable to look through. If the barrels are too close or the focusing knob is too small they may be more difficult and uncomfortable to use.
Features of Pocket binoculars
People do not buy this type of binoculars primarily for bird watching. However, these are a pair of binoculars that you can always carry in your pocket and when it comes to the situation to observe, you can take these binoculars and look through it.
They are usually better with 8x magnification than 10x because they are even smaller and easier to hold.
There are two series of Leica's pocket binoculars- Trinovid and Ultravid. Ultravid is considered to be one of the best and Trinovid is more entry level. Both have superior optics in a pocket format.
Ultravid is available in black and silver line and its armoring is made of black leather. Its overall appearance is truly amazing- it is extremely small and has a dual-hinge design which allows the binoculars to fold in two places and thus makes the binoculars even smaller (when folded).
As far as the Swarovski pocket binoculars are concerned, the latter presented only one series on the market, called CL pocket. There are two configurations of them, 8x25 and 10x25, available in black, hunting-green and sand colors.
Zeiss pocket binoculars are the latest among all mentioned above because they came on the market the last. They claim that they are the best in this category as far as the optical performance is concerned since they were presented later than the others and so it was possible to further improve them. They are also available in 8x25 and 10x25 and have a unique design with an interesting central bridge- the hinge is not symmetrical since the binoculars are folded so that the central focus knob is on the side.
Pocket binoculars are one of the smallest in the category of binoculars. As mentioned before, they normally feature roof prisms, instead of porro prisms. Since porro prisms are so much bigger, their size disables them to be a part of pocket binoculars construction. Binoculars with porro prism can never be folded as tightly as those with roof prism. This is the reason why pocket binoculars rarely (almost never) feature porro prisms.
Another important thing to point out is that pocket binoculars feature dual hinge mechanism. Since size plays such an important factor, one hinge mechanism is simply out of question. As you can see in the picture, dual hinge binoculars can be folded way closer than one hinge binoculars, which enables the user to simply store them in a pocket of a small space.
Since porro prism are bigger, they produce brighter, sharper and more realistic 3D images. Therefore porro prism binoculars can have better optical performance as equally priced roof prism counterparts.
One hinge binoculars and dual hinge binoculars
A short presentation of Pocket Binoculars is available here.