Binoculars review

Alpen Optics Rainier HD ED 8x42

Alpen Optics Rainier HD ED 8x42
5 May 2012
The Rainier series consists of the best and the most expensive pairs of binoculars in the Alpen Optics line-up. Not so long ago it included the following models: 8x32, 10x32, 8x42 and 10x42, all of them featuring Schmidt-Pechan roof prisms made of BaK-4 glass which reflective surface was covered by 60 metallic SHR coatings; it was supposed to minimize the light loss to about 1%. Additionally these prisms are phase correction PXA coated. All air-to-glass surfaces are covered by multilayer UXA coatings which, added to the prisms coatings, are supposed to provide the transmission reaching 90%.

In 2011 the company decided to introduce some changes in the 42 mm class. The 8x42 and 10x42 binoculars gained a new casing and low-dispersion glass in objectives so a new mark - HD ED - appeared on their bodies. Rainier binoculars’ casings are made of magnesium alloys covered by high quality rubber which is supposed to ensure they are fully waterproof; the fact that the instrument is nitrogen-filled makes the elements also fogproof. The A-Lock dioptre locking system allows faster focusing and saving of the chosen parameters. Twisted-up eyecups feature detents. The pair of binoculars is offered in an elegant case, along with an additional leather carrying case and a comfortable, wide strap. Like all the models of Alpen Optics binoculars, also the Rainiers come with lifetime warranty period. The binoculars of this series are produced in Japan.

  • Lornetka Alpen Optics Rainier HD ED 8x42
  • Lornetka Alpen Optics Rainier HD ED 8x42
  • Lornetka Alpen Optics Rainier HD ED 8x42
  • Lornetka Alpen Optics Rainier HD ED 8x42
Manufacturer data


Alpen Optics
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Distribution / Sales:

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Magnification Lens diameter Angular field of view Prisms Eye relief Weight Price
8 42 132/1000(7.5o) BaK-4/roof 18 mm 835 g 3949 PLN
Results of the review
Real front lens diameter Left:   42.05+/- 0.05 mm
Right:  42+/- 0.05 mm
8 / 8.0 pkt
Real magnification 8.01+/- 0.05x 3/3.0
Transmission 87.6+/- 1.5% 15/25.0
Chromatic aberration Low in the centre, a bit lower than medium on the edge. 7.3/10.0
Astigmatism Very low. 8.2/10.0
Distortion The distance of the first curved line from the field centre compared to the field of vision radius: 74% +/- 5% 9/10.0
Coma Appears near 80-85% of the field, being between medium and high on the very edge. 7.9/10.0
Blurring at the edge of the FOV The blur occurs in the distance of 79% +/- 2% from the field of vision centre. 5/10.0
Darkening at the edge the FOV Almost imperceptible. 4.7/5.0
Whiteness of the image Quite flat graph in the 500-700 nm range, noticeable slump for blue light but a bit smaller than in the 10x42 model. 4.1/5.0
Collimation Perfect. 5/5.0
Internal reflections
Left: Right:
Alpen Optics Rainier HD ED 8x42 - Internal reflections - Left Alpen Optics Rainier HD ED 8x42 - Internal reflections - Right
Housing Original ‘open-hinge’ casing. Average dimensions for this class of equipment. Very comfortable to hold and to look through. Rubberized eyecups can be set at three levels. It makes a very solid impression. The rubber comes off slightly near the objectives. 7.8/8.0
Focusing Big, comfortable, ribbed central wheel with the working range of 580 degrees. Individual focusing through a click-stop system on the central wheel. Nothing moves outside. Perfection. 5/5.0
Tripod There is a comfortable tripod exit but it is situated far from the binoculars’ centre of gravity. 2/3.0
Interpupilary distance from 55.9 to 74.2mm 5/6.0
Closest focusing distance 1.55 metres. 2/2.0
Eyepieces FOV Apparent field of view of 59.4 deg (according to simple formula) and 54.8 deg (according to tangent formula). 10/20.0
Field of view Measured by us amounted to 7.41 +/- 0.04 degrees and it was only slightly narrower than stated in the specifications. A typical field for this class of equipment. 6/8.0
Quality of the interior of the barrels Dark but only partially matt. Slightly shiny walls of inner tubes. Small, gray bottom. Some slight specks of dust inside. 3.8/5.0
Left: Right:
Alpen Optics Rainier HD ED 8x42 - Vignetting - Left Alpen Optics Rainier HD ED 8x42 - Vignetting - Right
OL: 1.28%, OR: 1.70%
Prisms quality High quality BaK-4. 8/8.0
Antireflection coatings Pink-orange on objectives, yellow-green-pink on eyepieces and pink on prisms. Low intensity. 5/5.0
Warranty [years] lifetime 6/6.0
Final result
148.1 / 190 pkt
Econo result 0pkt.


  • solid casing,
  • good transmission,
  • very low astigmatism,
  • slight coma,
  • chromatic aberration corrected in the right way,
  • excellent distortion control,
  • good whiteness rendering,
  • high quality of coatings and prisms,
  • low flares,
  • imperceptible light fall-off on the edge of the field of view,
  • minimum focus from 1.6 metres,
  • good warranty conditions.

  • slightly truncated exit pupils.

It is easier to implement 60-65 degrees eyepieces in 10x42 class binoculars than in 8x42 devices. As a result, in most of cases 8x42 instruments fare in our tests a tad worse than their 10x42 equivalents. The Alpen Rainier 8x42 HD ED is an exception to that rule – it scored slightly more points than its 10x42 brother. When all others lose the Alpen gets more. The differences are perhaps not huge but they allow the Alpen to qualify for the top-of-the-range group of our big test of 8x42 binoculars. The Alpen fares almost as well as the Zeiss Victory 8x42 T* FL, so praised by us.

Of course the Alpen yields to the Zeiss in several categories. The transmission is one of them and its graph is presented below.

However it would be difficult to expect a Schmidt-Pechan device faring better than an Abbe-Koenig model. Still, the Alpen’s achievements, especially when compared to those of the Zeiss, become even more impressive – it corrects distortion better and its area near the exit pupils looks nicer.

Pentax DCF 8x43 ED, Alpen Rainier HD ED 8x42 and Docter 8x42 ED.

That’s why our summary of the Alpen test is going to be even more positive than in the case of the 10x42 model. The Alpen kept the high level, its competitors didn’t. As a result the score of the tested binoculars is very similar to that of the more expensive Zeiss Victory and a bit better than the score of the Nikon HG 8x42 DCF, also very praised by us and as expensive as the Alpen. It would be difficult to think of a better recommendation.