Compact roof prism binocular.
� Field of view, real: 6.6� � Field of view, apparent: 51 degrees. � Field of view, real: 115m at 1km. � Weight: approx 215g � Diopter compensation: +/-5 dioptres � Interpupillary distance: 56-72mm. � (H x W x L) 38 x 93 x 101 mm � Waterproof and fog proof. � Eye relief: 13mm � Prisms: Schmidt-Pechan roof. � Phase coated: yes. � Eye tubes: screw in, screw out.
Content and images originally posted by Leif
Reviews
Leif's review
The Swarovski 8x20 B is a compact roof prism binocular with high quality optics. Priced at approximately �300, it is far from cheap.
Mechanics Like its competitors the Swarovski 8x20 B consists of two parallel tubes connected by hinges to a central bridge. The binocular is largely made of metal � it looks like black anodised aluminium � with Swarovski�s trademark green rubber armour partially covering the optical assemblies, and a plastic cover embossed with the Swarovski eagle on the bridge.
The hinges allow the user to adjust the eyepiece spacing, or fold the binocular for storage. It is surprisingly small when folded.
The focus wheel is mounted rather perversely at the far end of the bridge midway between the objectives. The focus can be annoying and hard to use for those used to a more conventional position. However after a few months I figured out that I could access the focus wheel from beneath with my left thumb: using this technique the focus wheel is very convenient. Fortunately the focus is smooth and is low geared i.e. a large number of turns are needed to move the focus from one extreme to the other.
The dioptre wheel is mounted on the bridge, midway between the eyepieces. It�s knurled, stiff, and functional.
The eye tubes screw in and out and are covered with rubber for comfort. They also unscrew to allow cleaning of the eyepiece lenses.
According to Swarovski the binocular is waterproof and fog-proof.
The binocular weighs a mere 215g and hence is lightweight.
A strap is supplied and is permanently attached. I was a little concerned that the strap could break free from the binocular, but in practice it seems well designed. I am still not convinced that a removeable strap would not be better.
The instrument is supplied with a woven Nylon case, with a Nylon zip, and a woven strap. In my opinion the case, though well made, does not quite match the standard of the binocular: I would prefer a more stylish leather case. It is also rather large, and importantly, the eyepieces risk being scratched if the binocular is stored with the eye tubes screwed in. To be fair to Swarovski the danger of the case scratching the eyepieces seems to be a general problem with compact binoculars.
The binocular is not supplied with objective covers or a rain guard and as far as I know none are available.
The overall build quality and finish are superb, and up to Swarovski�s usual high standards. The binocular is certainly robust: I regularly carry mine in a trouser pocket when out on a 4 mile run round the local nature reserve.
Optics
The optics are superb, and in good light provide an image that can rival much larger instruments. The field of view is very good � 115m at 1km � but does not match premium full sized instruments where 130m at 1km is more usual. Contrast and sharpness are excellent over most of the field, with very little softening at the edges and very little distortion. Chromatic aberration is almost absent, except at the field edges. Flare is not a problem except when viewing in the direction of the sun when it can be significant. (Note: never look at the sun, either with a binocular, or the naked eye, as blindness will result.) Ghosting is not a problem.
In good light brightness is excellent. On an overcast day the limitation of the small objectives is all too obvious, especially when compared side by side with a larger instrument. Nevertheless resolution is excellent even in low light due to the relatively high contrast. Another side effect of the small objectives is small exit pupils � 2.5mm � and hence eye placement is critical.
According to the manufacturer eye relief is 15mm. I can just about see the whole field of view while wearing eyeglasses, but the view is not comfortable. NB: The only comparable binocular that I am aware of that has sufficient eye relief for eyeglass wearers is the Opticron 8x21 DBA.
Close focus on my sample is just over 2m.
Conclusion
The Swarovski 8x20B is a first rate, albeit expensive, compact binocular. On the negative side the small objectives, and small exit pupil mean that it is not really suitable as a general birding glass. Furthermore, as it is not as well armoured as some competing products, it is susceptible to cosmetic damage. However, if you need a compact instrument with first rate optics, and you have deep pockets, then the Swarovski 8x20 B is strongly recommended.
Pros
- Small
- light
- nicely made
- excellent optics.
Cons
- Expensive
- restricted field of view
- not ideal for eyeglass wearers
- no rain guard or objective caps.
elkcub's review
My wife is the primary user of our 8x20B SLC. Fortunately, given a choice (which I rarely have), I still reach for the 10x25B SLC since it is easier for me to get grip on, and provides a bigger, brighter image. But in truth it does not focus to 8 ft. or provide as wide a field as the 8x20. My wife, therefore, has as big an advantage watching butterflies as I do with shore birding.
From an engineering perspective the Swarovski pocket binoculars are little marvels, each with 3-element objectives and 5-element eyepieces. Prisms of the most recent versions are probably SWAROBRIGHT coated, but even the older models are phase-coated and and use multi-layer SWAROTOP. In the case of the 8x20B, this is all packaged into 7.6 oz. and 4 in. length. The focusing wheel is located in the front, which is an under-appreciated and unique ergonomic innovation. It departs from conventional wisdom and allows the binoculars to be operated more easily under the bill of a hat. The focus controller would be classified as low gain, but allows very good precision. Most importantly, the beautiful images are bright and clear from edge-to-edge.
Discretely comparing the Swarovski 8x20B with its Leica, and Zeiss counterparts, I could not identify major optical differences � they all seemed superb. Admittedly, this had to be done from memory since in-store comparisons were not possible. However, until recently Swarovski held the edge in waterproofness, which was put to the test for us in Costa Rica where they really proved their worth. The advantage of the 10x25B was well proven on that trip, incidentally, since it was rather dark and wet, and the larger objective and bigger, brighter image made a significant difference. However, the 8x20B came into its own at the butterfly farm in Guatemala.
As mentioned in the previous review, no rainguard or objective lens covers are provided except the polytex pouch. This has proven convenient to suspend from my belt, although the leather pouch (extra charge) would probably be nicer for carrying it in a briefcase. Since none of these are hard cases, reasonable care must be taken in handling.
Okay, so where does that leave us? As a small general purpose instrument for travel or backup the 8x20B is unsurpassed (although it may be equalled). It is not a substitute for mid- or full-sized binoculars but it is a worthwhile item for those who enjoy owning the very best. Of course, that comes at a price. Within the restricted domain of 8x20 pocket binoculars, it deserves a top rating; however, as a general purpose birding instrument it takes a back seat to the more versatile 10x25B.
Pros
- Small size
- build quality
- optical excellence
Cons
- none
Joel Graber's review
On mine, the left tube comes right off. I've retraced my steps several times to find it on the ground. This is intolerable and nerve-wracking. Otherwise, I like this binocular; and it's especially convenient to wear it on the belt all the time. But I'm looking to supplant it now because of the errant eyepiece.
Pros
- Belt-go-anywhere-size
Cons
- Tube Glitch
