Alpen Teton 10x42 Binoculars Review

Whilst I have obviously known about Alpen Optics for ages, until now, apart from a few brief trials in-store or at shows, I had not yet had a chance to really give any of their binoculars a full test. On top of this, for me, it is always super interesting to test an instrument from a brand that I have not used before and so when I was contacted by them asking if I would be "willing" to test out some of their products, I jumped at the chance.

So with what I hope will be the first of many Alpen binocular reviews that you'll see on BBR in the future, we decided to start with what for me is probably their most intriguing series:

Alpen Teton Binoculars

Offered in either the 8x42 or 10x42 configurations, the feature that jumps out at me is that rather than the usual Schmidt Pechan design, the Teton incorporates Abbe-Koenig roof prisms to correct the inverted image.

Whilst not as compact and certainly heavier, the main advantage these Abbe-Koenig prisms have, is like porro prisms, all surfaces on them reflect 100% of the incident light and thus there is the potential for an improved low light performance, which should be especially noticeable in low light.

There are some other notable brands that use this prism design in some of their instruments, including many binos from Zeiss like the Victory HT series, some of Swarovski's instruments like the Swarovski SLC 15x56 HD as well as two of my favorites, the Maven B5 18x56 and the Vortex Razor UHD 10x42 binoculars, all of which are excellent low light performers within their respective configurations.

However, all of these others that I have listed above will cost you a whole lot more than the Teton and thus I was very interested to see how well a more affordable Abbe-Koenig binocular would perform, and below you can take a look at my thoughts after many weeks of testing:

Alpen Teton 10x42 Binocular Review

Features at a Glance:

• High-End Binoculars: RRP $669.99, Current Retail approx: $500 / £600
• Body
  • Single Bridge Body Design
  • Magnesium Chassis
  • Fog & Waterproof
  • Metal focus wheel
  • Twist-up metal eyecups
  • Tripod Adaptable
• Optics
  • Fully Multi-Coated Optical System
  • ED Glass Lens Elements
  • Abbe-Koenig Prisms
  • Phase Corrected
• Optical Stats
  • 15mm of Eye Relief
  • Wide FOV: 340ft @ 1000 yards
  • Excellent Close Focal Distance: approx 3ft - 4.3ft (0.9m - 1.3m)
• Comparisons
• Conclusions

The Body

Shape
As you would expect, both the 10x42 and the 8x42 Alpen Teton Binoculars use the same chassis and many of the outer parts used are the same and thus this part of the review will apply equally to both:

Due to the particular shape of the Abbe-Koenig prisms, it has resulted in an instrument that is a little bigger than most 10x42 binoculars, but I have to say this difference is less pronounced than other Abbe's that I have tested in the past.

Other than that the Teton looks and feels pretty typical for a modern roof prism binocular.

Exterior Rubber Coating
The exterior rubber coating on these Alpen Teton 10x42 binoculars is relatively hard and not quite as thick as used by some. This results in a good-looking finish, and it has a nice tight fit onto the chassis underneath.

Softer, thicker rubbers can sometimes move or slide about on the chassis if not glued on correctly but have the advantage of offering a little more impact protection and grip.

Alpen has countered this last issue somewhat by adding a diamond texture on the sides of the barrels which does help, but even so, you would never describe these bins as having a very high grip exterior.

The underside lacks any thumb indents, which is no biggie, but they can be somewhat comforting, and placed correctly can subconsciously just encourage you to hold them at the correct balancing point.

IPD (Inter-Pupillary Distance) Adjustment
Measuring 4.5cm across, the bridge is wide for the top-hinge designs out there and fairly standard for a normal single hinge design and being made from metal, I have no concerns regarding its strength.

The hinge itself opens and closes with a good level of resistance and thus is not too difficult to do, but will remain at your desired setting.

Speaking of which, I measured the IPD (Inter-Pupillary Distance) range on these 42mm Alpen Teton binoculars to go from 6cm up to a maximum of 8cm which for a 42mm roof prism binocular is pretty standard.

Chassis
A hidden feature, but a definite sign of quality is the use of a chassis made from magnesium alloy and not a polycarbonate plastic that I see more and more these days.

A good metal chassis has the potential to be more robust (not always the case, depending on the design and exact materials used). as well as this, magnesium also has an excellent resistance to temperature-related expansion and contraction and thus any misalignment of the optics due to to extreme temperatures is minimized.

Fully Sealed
As you would expect at this level, but is always good to confirm, the Alpen Teton 10x42 binoculars are sealed and thus are fully waterproof and not just "weather protected".

The air in the interior cavity is also pumped out and replaced with a dry nitrogen gas during manufacture which prevents fogging on the internal lens surfaces.

Eye-Cups & Eyepieces
Whilst difficult to be sure, the eye-cup housing on these Alpen Teton binoculars looks to me to be made from metal and not plastic as is now quite often the case. The padded section is attached very firmly and even though it is made from a thin rubber, is no less comfortable than what I would consider being normal.

A definite highlight is the twist-up mechanism, which is truly excellent: With no free play or looseness, there really is a noticeable feel of quality to the whole system and I especially love the way they very positively snap into each of the three click-stops.

The only slight reservation I have is the 15mm of eye-relief, which has to be said is not bad, but does fall a little short of what I would consider to be classed as long.

Focus Wheel & Focussing

The Alpen Teton 10x42 Binoculars have an excellent focus wheel and certainly one of the better ones out there.

Firstly unlike many, many binos, including some "alpha" level ones (Swarovski comes to mind), metal and not plastic is used for the main material. Whilst structurally this is probably overkill, but it just looks, feels and simply works better than the average plastic focus wheel out there.

The wheel is also prominent, well positioned and quite large (34mm diameter & 20mm long) which I found makes it very easy to find and reach from the standard grip when holding the bino up to your eyes.

Then there is the deeply etched diamond pattern on the outer surface of the wheel that delivers an excellent level of grip. During normal day-to-day use, this not that important, but in winter when wearing thick gloves, this along with the other aspects that I have already mentioned really helps in ensuring rapid an accurate focal adjustments.

The focus mechanism on my sample was also very smooth, but perhaps a fraction too tight, but this is very minor and I think preferable to being too loose and sloppy.

In terms of the gearing, it takes just over one full turn (about 450°) to adjust the focus from one extreme to the other. This is what I would describe as quite aggressive gearing, making it nice and quick to make large focal adjustments but is technically a little more difficult to make fine adjustments, however, I never really experienced a major issue in this regard.

Lastly, I'd like to mention that whilst I like the Alpen stamped faceplate on the rear of the wheel, but it is just a slight shame that they decided to use plastic and not metal as well.

Diopter Adjustment

Matching the focus wheel, the diopter adjustment ring is also made from metal with the same diamond pattern etched into it, which is not really necessary, but it looks great and I certainly prefer it over the many plastic ones out there.

Used to calibrate the binocular to match the vision in your eyes, you only need to adjust it very infrequently and thus a good diopter in my opinion should remain at your desired setting without any chance of being moved by accident.

Some high-end binoculars have a lockable diopter and indeed I did read that the the ring on these was lockable, but I did not find this to be the case. However, I will say that the diopter ring on my sample Alpen Teton Binocular has a tight mechanism and is fairly inconspicuous and thus is unlikely to move to easily by accident.

In terms of markings, there really only is the neutral marker and a + and - sigh to work with and thus if you have a particular setting that doesn't line up with any of these, I would suggest making a small mark with a permanent market or a small nick with a sharp knife.

Tripod Adaptable
Being "tripod adaptable" means that it is very easy to attach the Alpen Teton Binocular to a tripod/monopod using an ordinary tripod adapter.

To do this, you simply unscrew the cap from the front face of the hinge and then screw in the adapter, which you can then attach onto your tripod head. I found that the gap between the barrels to be sufficient and thus it should accept most adapters without issue.

Body Quality Score: 9/10

Weight
It is not surprising considering all the metal components and the use of Abbe-Koenig prisms�to discover that the Alpen Teton binoculars are not the most lightweight 42mm instruments out there.

However, I found them to be well balanced and for me the feeling of quality you get on an instrument like this is well worth the trade-off unless you specifically need a very lightweight instrument. In which case, you may be better off opting for a smaller mid-sized option instead.

Dimensions
As I mentioned at the top of the review, one of the downsides to the the Abbe-Koenig prisms and one of the main reasons why the Schmidt-Pechan roof prism is so popular is that they are far less compact.

So as you can see in the table above the Teton is on the larger end of the scale when compare to many other roof prism 10x42 binoculars, but I have to say this difference is less pronounced than on other Abbe's that I have tested in the past and thus this should not be an issue unless you are specifically looking for a "compact" 42mm instrument. As with the weight, if dimensions are critical to you, perhaps opting for a smaller mid-sized 32mm binocular could be a better option for you.

Body Stats Score (for a 42mm binocular): 8/10

Optics

Ocular Lenses

Alpen Optics does not supply any information regarding the makeup and/or the arrangement of the lenses in their eyepieces, so I can't really comment.

What I can say is that the outer ocular lens has a diameter of 20mm, which I have to say, is a little less than the largest ones that I have measured on a 42mm binocular. Larger oculars can offer a number of advantages, for more, take a look at my article on Binocular ocular lens size.

Objective Lenses

I measure the 42mm lenses to be set back about 8mm in from the ends of the barrels, which is reasonably deep and thus they are reasonably well protected.

ED Glass
Whist Alpen does not include any extra information in regards to the make-up of the lenses other than to confirm they use ED (extra-low dispersion ) glass.

ED glass in the lenses offers the lens designer more options when it comes to controlling the wavelengths of light as they split up going through the lens and thus they have the potential to reduce chromatic aberrations, which in turn has the potential to produce a higher definition image showing less color fringing around the edges of objects.

Be sure to read through the Image Quality section below to see just how well I thought these performed in this area.

Abbe-Koenig Prisms

as I have already mention numerous tomes in this review, these Alpen Teton binoculars use Abbe-Koenig prisms to erect the image, which is a type of roof-prism, but is different from the much more commonly used Schmidt-Pechan design found in most modern roof-prism binoculars:

Total Internal Reflection
Whilst longer and heavier than Schmidt-Pechan prisms, the Abbe-Koenig design offers a number of important advantages over them, not least that they have a total internal reflection, meaning 100% of the light entering the prism also exits it and thus no mirror coatings are needed.

With the Schmidt-Pechan design, you do get some loss and thus even with the very best roof prism binoculars that use special dielectric mirror coatings, you still get a percentage of light that is not transmitted.

Finally, unlike the Schmidt Pechan design where the light exits exactly in-line with the entry path, with an Abbe-Koenig roof prism is it is possible to have the light exit slightly offset to the path of entry, which is why most Abbe-Koenig binoculars have the eyepieces set closer together than the objectives, which is not that obvious with these, but I think they may be a light difference between the centers of the oculars and the objectives.

Optical Coatings

Anti-Reflection Coatings
Whilst at this alpha level, I would have been completely shocked to learn differently, it is important to confirm that these Alpen Teton 10x42 binoculars are Fully Multi-Coated.

This means that all lens surfaces throughout the entire optical pathway have multiple layers of a special anti-reflection material added to them which greatly increases both image quality and brightness.

Lesser quality instruments will only be multi-coated or fully coated, meaning only some air-to-glass surfaces will be coated and some with only a single layer.

More: What To Look For When Buying Binoculars & Anti-Reflection Lens Coatings.

Prism Coatings
Alpen Optics advertise that they use their PXA phase coating, which means phase correction coatings have been added to the prisms which eliminates the problem of the individual wavelengths stepping out of phase with each other as they pass through the prism. The result is improved image resolution and contrast.

Protective Lens Coatings
Some binoculars at this and especially the higher price points will also include special protective coatings to the outer lens surfaces which can help protect from things like scratching and be water and/or oil repellent. As Alpen Optics do not highlight the fact, I will assume until informed otherwise that they do not use anything outside of the ordinary.

Coating Comparisons

Optical Components Score: 9/10

Optical Stats

The Field Of View (FOV)
The Alpen Teton 10x42 binocular offers up a view that is advertised as being 340ft wide/high at a distance of 1000 yards away (approx: 113m @ 1000m), which as you can see from the comparison table below certainly ranks up there with some of the better 10x42 binoculars on the market and makes them better than most 10x binoculars for scanning wide areas looking for something or indeed following fast moving wildlife/objects at closer ranges.

Close Focus
In their specification sheet, Alpen list the 10x42 Teton as having a "Close Focus" of 3ft. For a full sized 10x42 binocular, this is truly superb and if true, I think would be the best that I have so far come across.

I tested my sample and have I was not able to achieve a sharp focus until I was about 4.3ft / 1.3m away from any object.

Here on BBR I rate a minimum focus distance of 6ft (1.8 meters) or less on a standard full sized instrument like these as being excellent.

So either way, these Alpen 10x42 Teton binoculars are truly superb in this area, which along with their wide FOV (for a 10x42) makes them a great option should you also like to occasionally study objects like butterflies, flowers or indeed birds from very close range.

Eye-Relief:
As I have already mentioned earlier in the review, the twist-up eyecups on these Alpen Teton binoculars are excellent, but at 15mm, the level of eye-relief is not bad, but does fall a little short of what I would consider to be Long Eye-Relief and this if you need or want to wear eye-glasses or sun glasses whilst using your binoculars this may be an issue.

I did check this by using my glasses and by fully twisting down the eyecups, I was just able to take in the full image without any tunneling effect / black rings forming on the edges, but it was close and I did not have much room for manoeuver. Thus if you wear thick framed glasses, I would suggest taking a look at the 8x42 version which comes with an improved 17.3mm.

For more on this, be sure to check out my guide on How To Use Binoculars With Glasses.

Optical Stats Score for a 10x42 binocular: 9/10

Optical Performance

Describing, quantifying and rating the view through the binoculars is by far the hardest part of any review I write, yet I am sure you would agree, it is also the most important!

To help me to be as fair and consistent as possible, I use a number of "benchmarks" (with the same or similar configuration) that I use for all my reviews to compare and then rank the view against. So for this review, I closely compared the view through these Alpen Teton Series binoculars against my "alpha" level 10x42 and mid-level 10x42 benchmarks on a number of occasions in a variety of light conditions and below are my thoughts:

Colors & Contrast
Comparing all three once again in a wide range of scenarios and light conditions, the colors and level of contrast in the image to me looked to be pretty much identical to my alpha benchmark 10x42 and both slightly better than the mid level instrument.

There was also no obvious unnatural tinting of the view and the colors to me looked vibrant, but not so much so as to make the view look artificial.

The same can be said of the contrast, which shows a good variation between dark and light areas, but is not too harsh.

Image Brightness
As to be expected (unless the optics are particularly bad), all three 10x42 binoculars looked very close in terms of image brightness in sunny conditions and even when looking into thick foliage the difference between them was tough to observe, but if I had to pick, I would say that these Teton's and my alpha's looked to perform a little better that the mid-level 10x42 benchmark.

It was in sub-optimal light conditions when the difference in the quality of the optics makes for a more observable difference and I could clearly see that both these Alpen Teton 10x42 binoculars and my alpha level benchmarks outperformed the lesser quality instrument as the view on both was notably brighter and you could certainly see more detail when looking into thick bushes etc.

So for image brightness in low light, I definitely rate these Alpen Teton Binoculars as truly excellent for a 10x42 binocular.

Color Fringing
These Alpen binoculars have ED glass elements within each of the objective lenses which can help reduce chromatic aberrations, and as a result help reduce the amount of color fringing you see in the final image and thus I was expecting theses to do well in this area:

In normal use, you will probably never really notice it, but under extremes, like looking along the edges of a black telephone line against a bright blue sky, you can observe some color fringing (I could see a thin cyan line on the underside and a magenta one on top) and whilst I would say that it was fractionally more than on my alpha's, the level was still minimal for a 10x binocular and thus they did well.

Flatness, Image Distortions & Blurring
One area where these performed particularly well was with the distinct lack of image softening / vignetting right at the edges of the view (almost non existent), which in my experience is as good as any instrument I've used.

Also to point out that once I had focused on an object at the center of the view, it remained sharp and in focus right to the edges.

I also never observed any sort of image curvature or other image distortions when looking through them which would obviously be undesirable.

Score for Image Quality: 9/10

Included Accessories:

These Alpen Teton 10x42 binoculars come supplied with the usual mix of accessories which includes a carry case, neck strap, lens covers, cleaning cloth and instructions. However on top of this you also get a special Lens Cleaning Pen which is great to see:

Carry Bag
In general, the stitching and overall quality of the carry case looks good and whilst the amount and thickness of the internal padding is minimal, it has a semi-rigid design that does provide what i feels is an adequate level of protection.

The material used on the interior is nice and soft and on the inside of the bag, there is are also a couple of extra pockets that makes a great place to keep the cleaning cloth and perhaps some other small items for use when out in the field.

One issue I had was due to these Teton's being a little longer than your average 10x42, it mean that it was quite difficult to fit them into the bag without having to twist down the eyecups, which leads me to believe that even though it has the Alpen logo printed on it, this case is somewhat generic and certainly not designed specifically for these exact binoculars, which is a little bit of a shame.

The bag has two closures, firstly there is a zip that goes right around three sides of the case. Then on top of this there is a flip over lid that is held down with a strip of Velcro.

These two fasteners make for an extremely secure case that is probably not that necessary as having to open both of these to gain access to your instrument does take a little extra time.

To get around this, my advice is to leave the zip completely open when in the field and just use the Velcro closure. Then once back home and storing your optics or when travelling, you can use both for the added security and complete protection against dust.

Also note that with the zip and Velcro closures, some users like birders or hunters who need to remain silent will also have to be careful when using them. It is in these situations that magnetic fasteners, whilst less secure may be preferable.

The bag also comes with its own unpadded carry strap that can be removed using the quick release clips. On the rear of the bag, there is a belt loop.

Neck Strap
I really like the neck strap that comes included with these Alpen Teton binoculars:

Whilst perhaps a little on the thin side (37mm wide x 5mm deep), the padded section is made from what looks like a Neoprene type of rubber which is left uncovered on the underside for added grip which does a good job of prevent the strap from sliding about around your neck and shoulders.

The upper surface is covered with a fine material, the stitching looks excellent and the strap is branded with the Alpen logo.

Attaching the thin nylon section of the strap to the binocular is achieved in the normal way by threading them through the eyelets on the sides of the instrument and then back on them self and through a slider which enables you to adjust the length of the strap.

This tried and tested method works well enough, but can be a little time consuming to set-up and then remove should you wish.

However, the great news in this regard is that there are also a couple of quick-release clips on these sections. This means that once set-up you can easily and very quickly remove the padded neck section. You can then connect the two clips to form a hand strap or they can be used to attach the binocular to a harness.

This is another small but excellent attention to the detail that I really appreciate.

Objective Lens Covers
I really like the way the cover is designed to fit into the ends of the barrels and not over the ends of them which is often the case on others. This makes for a more integrated look and thus they feel like they are a part of the overall package rather than just being an afterthought thrown on at the end.

Also important to mention is that the cover fits very well and as a result should not come away by accident. For me the only slight shame is that it is not tethered to the body of the binocular in some way which would negate the need to either store it somewhere when glassing or attach it to the neck-strap through the loop hole on the side. This works, but I find that this method means that the cover can often just get in the way. This is just my preference and I am sure there are others who will disagree.

Cleaning Cloth & Lens Cleaning Pen
As well as a good quality micro-fiber cleaning cloth, Alpen also includes a special lens cleaning pen which is excellent.

On one side of this you get a retractable brush and on the other is a cleaning tip.

Instructions
The included instruction booklet is relatively comprehensive, and covers topics like the main parts, eyecup adjustment, IPD adjustment, diopter adjustment, neck strap attachment and cleaning. The cleaning pen comes with its own set of instructions.

Lifetime Warranty
The Alpen has a USA Limited Lifetime Warranty, but be sure to register it within 60 days of purchase. This can be done online and the included card will give you all the details.

Accessories Score: 8/10

Alpen Teton 10x42 Binocular Comparisons

From the table below, you can compare some of the details of these Alpen binoculars against a small selection of other High-End ($500-$1200 / £500-£1200) 10x42 binoculars in the BBR database.
Open table in full-screen mode to view the full results.

Review Conclusions:

With the Teton 10x42, I think Alpen have created what is overall a truly excellent lower costing Abbe-Koenig prism binocular and whilst understandably it does fall a little short is some periphery areas when compared against some of the other very high-end "Abbes" on the market that cost twice as much or more, I feel they have got the most important aspects as to why you would use this prism design completely nailed as the Alpen Teton 10x42 binocular really does perform in low light, enabling you to get up earlier, stay out longer, and view more detail in thick vegetation.

What I Like

Optical Components and Image Quality
The Alpen Teton binoculars use very high-end optics at a price well below what you would usually expect to pay for an Abbe-Koenig bino. Yet, with these, you still get a high-quality image and what I consider an excellent low-light capability for a 10x42 binocular.

Components Used & Build Quality
Whilst not as lightweight as plastic, I am sure most users will appreciate all the high-quality metal components that includes a magnesium chassis, metal eye-piece housings, focus wheel and diopter ring, which in combination with the obvious build quality all add up to an instrument that looks and feels great, that I am sure with care, will last a lifetime.

Focusing
I really like the all-metal focus wheel, not only does it look great, but it's design combined with a smooth focus mechanism make it a pleasure to use with or without gloves on.

Field of View
For a 10x powered instrument, these Alpen Teton 10x42 binoculars have a nice and wide field of view, ideal for scanning wide areas or following fast moving wildlife at closer ranges.

Close Focus
The minimum focus distance matches that of the very best in this area.

Neck Strap
The included neck strap is very good. Whilst perhaps a little lightweight and thin, it is reasonably well padded, has a non-slip underside and I really like the quick-release clips which enable you to easily remove the padded section and either convert it to a hand strap or attach it to a harness.

Room For Improvement

Eye-Relief
With 15mm, the Alpen Teton 10x42 Binocular has a reasonable amount of eye-relief, but there will be those who wear thick framed glasses, that will desire more to ensure that they can achieve the entire field of view. If this is the case, I would suggest taking a look at the 8x42 version which comes with an improved 17.3mm.

Carry Case
Whilst the quality is good one small issue I had was that it was quite difficult to fit the binocular into the case without twisting down the eyecups, not a deal breaker by any means, but a little bit of a shame and could easily be rectified.

Objective Lens Covers
The cover that protects the two objective lenses works perfectly well and I like how it fits into the ends of the barrels, I just prefer the type that is tethered to the body of the instrument for a little easier access.

Ideal Uses

• Wildlife Observation & Hunting
• Longer range Birdwatching - like from a hide overlooking a lake or at the coast
• General Use