Swarovski Optiks are all about quality and everybody knows that and they back their products with a lifetime warranty, so that says it all. And when we talk about quality, we mean everything not only the optics. Just by looking at the instrument you know you're looking at quality.
For starters these binoculars not only carry the name of 'pocket binoculars' for nothing they are that as well. You will hardly find any pocket binocular which fit the requirements as the ones from Swarovski. They all fit into the pocket of any jacket even a shirt; on top of this they are very lightweight maximum 8.1 ounce (some less than 7 ounces!)
These instruments are not exactly the same, even though it might seem so from what I've argued up to this point. The differences in appearance and certain specifications may just be what you were looking for to base your final choice on.
Some are 8x and some 10x.
Swarovski offers two 8x20B-P ones, one green and one black, as well as one Traveler: Swarovski Optiks Pocket Traveler Binocular, 8x20. In addition to these they offer luxury models, the Swarovski crystal series (Crystal Tosca, Nabucco and Idomeneo) as well as the Swarovski Tyrol.
Swarovski Optiks Pocket Binocular (10x25B-P, Black)
Swarovski Optiks Pocket Binocular (10x25B-P, Green)
Swarovski Optik Pocket Traveler Binocular, 10x25 mm
Obviously you have more magnification with the 10x models, but that comes at a price. If you don't have a steady hand, don't even consider any binocular with a magnification of 10 times. The problem with higher power is the fact that the slightest movement (either from the object you're trying to look at, or your own hand holding the instrument) is exaggerated.
Another problem associated with higher power has to do with the exit pupil. Since the exit pupil is calculated by dividing the diameter of the objective lenses by the magnification, it means that higher magnification inevitably means smaller exit pupil size unless the objective lenses are made bigger. This is what Swarovski Optiks did (all the 10x's have 25 mm lenses at the front). (Smaller exit pupil will deliver less light to your eyes, which will become a problem in fading light.)
Objective lens size:
All of the 8x power binoculars have apertures of 20 mm, whereas the 10x power binoculars have apertures of 25 mm. As argued above, the main reason being to compensate for the loss of exit pupil diameter.An advantage of the wider objective lenses (25 mm) above the 20 mm is the fact that wider lenses gather more light than smaller lenses. This means that the 25 mm lenses binoculars will be more effective in dim light than the 20 mm aperture binoculars.
There's a marginal difference between the two groups based on objective lens size: Bigger objective lenses always weigh more and that accounts for 0.5 ounces difference: The 8x20's weigh 7.6 ounces and the 10x25's 8.1 ounces.
Dimensions:The dimensions of the 8x20's are exactly the same: Their height is merely 1.5 inches, they fold up to an incredible 2.3 inches and their length is not even 4 inches (3.98 inches). The 10x25's have the same height (1.5 inches) and width (2.3 inches), but are slightly longer (4.57 inches).
Field of view (FOV):
Usually (but not necessarily so) higher magnification means narrower FOV and this is indeed the case with these Swarovski Optiks pocket binoculars. The 8x's have a FOV of 345 feet @ 1,000 yards (6.6 degrees), whereas the 10x's are limited to 285 feet @ 1,000 yards (5.4 degrees). A wider field of view is handy to find an object in the distance and in particular to follow a moving object.
A shorter binocular can focus closer than a longer binocular. The 8x20's have a close focus ability of 13 feet, whereas its 16 feet in the case of the 10x25's. You won't even see the difference. However, if you really want to focus on small things like insects, you should consider the Pentax Papilio, which can focus as close as 18 inches. Unfortunately this instrument is overall not in the same class as the Swarovski's.
Prices vary considerably from $679 for the 'standard' and Traveler 8x20's, to $899 for the 8x20 crystal models (the Tosca, Nabucco and Idomeneo). The only difference between these binoculars is the look. The crystal models looks like a beautiful piece of jewelry in addition to being binoculars and small wonder, since the crystals are the famous Swarovski crystals. Between these two poles the 10x25's are sold for $769 and the Tyrol 8x20, also a luxury model, for $840.