Binoculars review

Opticron Discovery 10x42 WP

Opticron Discovery 10x42 WP
16 February 2010
The Discovery WP series consists of two very small and physically light roof prism binoculars with the following parameters: 8x42 and 10x42. The tested binoculars was actually the smallest instrument here with the height amounting to just 126 mm.

This series’ instruments are waterproof, nitrogen-filled and they feature BaK-4 glass prisms. All air-to-glass surfaces were covered by antireflection multilayer coatings.

  • Lornetka Opticron Discovery 10x42 WP
  • Lornetka Opticron Discovery 10x42 WP
  • Lornetka Opticron Discovery 10x42 WP
  • Lornetka Opticron Discovery 10x42 WP
Manufacturer data


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Distribution / Sales:

Olbrycht Trade sp. z.o.o.
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Magnification Lens diameter Angular field of view Prisms Eye relief Weight Price
10 42 87/1000(5o) BaK-4/roof 18 mm 682 g 1050 PLN
Results of the review
Real front lens diameter Left:   41.7+/- 0.05 mm
Right:  41.8+/- 0.05 mm
7 / 8.0 pkt
Real magnification 10.2+/- 0.2x 3/3.0
Transmission 66+/- 3% 4.5/25.0
Chromatic aberration Slight. 6/10.0
Astigmatism Medium. 5.6/10.0
Distortion The distance of the first curved line from the filed centre compared to the field of vision radius: 60% +\- 8% 7/10.0
Coma Distinct. 3.8/10.0
Blurring at the edge of the FOV The blur occurs in the distance of 83% +\- 3% from the field of view centre. 6/10.0
Darkening at the edge the FOV Very low. 4.4/5.0
Whiteness of the image Light grey-pink. 4.1/5.0
Collimation Perfect. 5/5.0
Internal reflections
Left: Right:
Opticron Discovery 10x42 WP - Internal reflections - Left Opticron Discovery 10x42 WP - Internal reflections - Right
Housing Very small. Stinking rubber on the casing. The eyecups twist up but are too short. A lot of grease. Solid, comfortable to hold. 6.3/8.0
Focusing Central screw is convenient, the individual focusing on the right eyepiece – not so. Everything moves inside. 4.3/5.0
Tripod The exit is not very comfortable. 2.5/3.0
Interpupilary distance from 57.2 to 74.2mm 5/6.0
Closest focusing distance 1.15 m. 2/2.0
Eyepieces FOV Apparent field of view of 48.8 deg (according to simple formula) and 46.2 deg (according to tangent formula). 3/20.0
Field of view Measured by us amounted to 4.79 +\- 0.03 degrees and it was by 0.21 degree narrower than in specifications. A very narrow field of view for this equipment class. 4/8.0
Quality of the interior of the barrels Dark but shiny. Scratched bottom. A lot of specks of dust. 3/5.0
Left: Right:
Opticron Discovery 10x42 WP - Vignetting - Left Opticron Discovery 10x42 WP - Vignetting - Right
OL: 0.0%, OP: 0.6%.
Prisms quality Good quality BaK-4. 8/8.0
Antireflection coatings Green-purple everywhere. Medium intensity. 4.5/5.0
Warranty [years] 5 3.5/6.0
Final result
45th place in the overall ranking of the 10x42 binoculars’ test.
113.6 / 190 pkt
Econo result 34th place in the econo ranking of the 10x42 binoculars’ test. -0.6pkt.


  • solid and compact casing,
  • slight distortion,
  • chromatic aberration quite well corrected,
  • very low brightness loss at the edge of the field,
  • sharp image already from the distance of 1.15 metres!
  • good quality of prisms.

  • very narrow field of view,
  • low transmission,
  • average blackening inside the barrels,
  • significant coma,
  • not very fragrant rubber on the casing.

Once again the price is not adequate to the possibilities. If only the Opticron Discovery cost 100-200 USD it would be able to compete successfully with such binoculars as the Vortex Crossfire, the Vortex Sidewinder or the Delta Optical Forest and it would be also one of our favorites in the lowest price segment. Seeing the price tag around 300 USD we might start to get interested in other instruments which fared much better and have a wider field of view ( like the Ecotone AD-7, the Vixen Apex Pro, the Eschenbach sektor D compact 10x42 B or the Swift Ultralite).