Binoculars review

Alpen Optics Rainier 8x32

Alpen Optics Rainier 8x32
27 April 2011
The Rainier series consists of the best and the most expensive sets of binoculars offered by the Alpen Optics company. It includes models with the following parameters: 8x32, 10x32, 8x42 and 10x42. All of them feature Schmidt-Pechan roof prisms made of BaK-4 glass which reflective surface was covered by 60 SHR metallic coatings; it is supposed to minimize the loss of light to about 1%. Additionally the prisms are covered by the phase PXA coating. All air-to-glass surfaces in the binoculars of this series are covered by UXA multilayer coatings; with the coatings on the prisms, they are to guarantee the overall transmission of this instrument reaching 90%.

The bodies of Rainier binoculars are made of magnesium alloys covered by high quality rubber padding which task is to ensure that the instrument is fully waterproof; as they are also nitrogen-filled, humid air won’t steam up the lenses. The A-Lock focusing system makes sharpening quicker and the chosen parameters can be remembered more easily. Twist-up eyecups feature a twist lock. The binoculars are offered in very stylish packaging; it has also a leather case and a wide, comfortable strap. Like all Alpen Optics binoculars models, the Rainier instruments come with lifetime warranty. The binoculars from this series are produced in Japan.

  • Lornetka Alpen Optics Rainier 8x32
  • Lornetka Alpen Optics Rainier 8x32
  • Lornetka Alpen Optics Rainier 8x32
  • Lornetka Alpen Optics Rainier 8x32
Manufacturer data


Alpen Optics
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Magnification Lens diameter Angular field of view Prisms Eye relief Weight Price
8 32 141/1000(8o) BaK-4/roof 18 mm 710 g 3199 PLN
Results of the review
Real front lens diameter Left:   32.05+/- 0.05 mm
Right:  32.05+/- 0.05 mm
8 / 8.0 pkt
Real magnification 7.99+/- 0.05x 3/3.0
Transmission 89.9+/- 1% 17/25.0
Chromatic aberration Lower than average in the centre and on the edge of the frame. 6.3/10.0
Astigmatism Very well-corrected. Almost point-like stars, they spark just slightly. 8/10.0
Distortion The distance between the first curved line and the field centre compared to the field of vision radius: 91% +/- 3% 10/10.0
Coma Occurs more or less in the distance of 2/3 of the field of view radius but it is low and not much higher on the edge. 8.5/10.0
Blurring at the edge of the FOV The blur occurs in the distance of 80% +/- 3% from the field of view centre. 5.5/10.0
Darkening at the edge the FOV Slight. 4.3/5.0
Whiteness of the image Very delicate hue of cream. The transmission in the blue part of the spectrum could have been a bit higher. 4.1/5.0
Collimation Perfect. 5/5.0
Internal reflections
Left: Right:
Alpen Optics Rainier 8x32 - Internal reflections - Left Alpen Optics Rainier 8x32 - Internal reflections - Right
Housing Rubber-coated, very solid, very comfortable to hold and to look through. Twist-lock eyecups made of hard rubber, with four click-stops. The rubber sticks out a bit near objectives. 7.7/8.0
Focusing A comfortable central wheel which moves smoothly but is well-damped. The full turn takes 380 degrees. A comfortable and big individual focus ring. It is rubber-coated, ribbed and can be shifted (it works in the range from –7 to +7 dioptres). It moves the lens. 4.5/5.0
Tripod Jest wygodne wyjście. W teście 8x32 wszystkim lornetkom przyznaliśmy w tej kategorii średnią wartość 1.5 pkt., jako że wyjście statywowe w tej klasie sprzętu jest rzadko używane. 1.5/3.0
Interpupilary distance from 55.3 to 73.5mm 4/6.0
Closest focusing distance 0.95 m 2/2.0
Eyepieces FOV Apparent field of view of 63.9 deg (according to simple formula) and 58.4 deg (according to tangent formula). 13/20.0
Field of view Measured by us amounted to 8.00 +/- 0.03 degrees and it was in perfect accordance with the specifications. A big field for this class of equipment. 6.5/8.0
Quality of the interior of the barrels Inner tubes black and matt, grey bottom. Clean. 4.5/5.0
Left: Right:
Alpen Optics Rainier 8x32 - Vignetting - Left Alpen Optics Rainier 8x32 - Vignetting - Right
OL: 5.3%, OR: 4.1%
Truncated exit pupils.
Prisms quality High quality BaK-4. 8/8.0
Antireflection coatings Purple-pink on objectives. Yellow-pink on prisms. Pink-yellow-blue on eyepieces. Low intensity. 5/5.0
Warranty [years] Lifetime warranty 6/6.0
Final result
148.9 / 190 pkt
Econo result 0pkt.


  • very solid casing,
  • good transmission,
  • good whiteness rendition,
  • wide field of view, perfectly in accordance with the specifications,
  • sensationally corrected distortion,
  • slight astigmatism,
  • low coma,
  • slight brightness loss on the edge of the field,
  • minimum focus from less than 1 metre,
  • high quality of prisms and coatings,
  • liftetime warranty.

  • ignificantly truncated exit pupils,
  • a bit too heavy for a 32 mm class instrument

Let’s start with the advantages. Perhaps the most important thing in our test is the final result of the Alpen which positioned this instrument between such models as the Leica Ultravid HD and the Swarovski EL. A really impressing place, especially if you take into account the fact that the Rainier 8x32 is over two times cheaper than both its rivals, mentioned here.

The tested set of binoculars is well-put-together, it corrects the distortion splendidly, its astigmatism, coma and brightness loss on the edge are low; what’s more it features good quality of prisms and antireflection coatings. The transmission graph presented below, shows that we deal here with a top-of-the-line instrument indeed. No outstanding results there but still they are very good. In the wide range near the visible spectrum’s centre the binoculars lets through about 90% of light which allows to get nice, crisp image without unwanted colour casts and hues.

Looking at the weight of the binoculars, which amounts to 710 grams, many things become clear. Most 42 mm class binoculars can weigh less than 700 grams. For example the Alpen Wings ED 10x42, tested by us not so long ago, weighed only 595 grams – significantly less than the Rainier 8x32. Yet again we get the confirmation of a principle that the usage of solid, big glass elements, which are definitely not as light as a feather, will pay off, assuring good optical properties. The performance of the Leica Ultravid HD, though, looks even more impressive as it is significantly smaller and physically lighter than the Alpen and despite that fact it managed to achieve a better result in our test. It is also one of the reasons why the Leica is also over two times more expensive than the Alpen.

Honestly, the only thing that really worries us in the Rainier 8x32 are these truncated exit pupils. It shouldn’t have happened in the case of an expensive instrument with such dimensions and weight. After all we decide to put up with a heavy pair of binoculars just because we want to get huge prisms without vignetting.

The rest of the Ranier’s properties is composed of practically only advantages. If the weight is not a problem you will be a very satisfied user of this set of binoculars, especially that it comes with a lifetime warranty.