Bushnell Discoverer 10x42
In all these binoculars Bak-4 prisms PC-3 phase correction coated were used. Additionally, all air-to glass surfaces were covered by high quality antireflection coatings, including specially designed, efficient XTR coatings. The outer lenses were covered by special Rainguard® layers which allow to remove dampness and dirt more easily.
These binoculars are waterproof and nitrogen-filled; they come with a 30-year-long guarantee and a comfortable eye relief.
| Magnification | Lens diameter | Angular field of view | Prisms | Eye relief | Weight | Price |
|---|---|---|---|---|---|---|
| 10 | 42 | 114/1000(6.5o) | BaK-4/roof | 17 mm | 800 g | 2375 PLN |
| Real front lens diameter |
Left: 42.03+/-
0.05 mm Right: 42.05+/- 0.05 mm |
8 / 8.0 pkt | ||||
|---|---|---|---|---|---|---|
| Real magnification | 9.85+/- 0.15x | 3/3.0 | ||||
| Transmission | 87+/- 3% | 14.5/25.0 | ||||
| Chromatic aberration | Low in the centre, average at the edge. | 6.9/10.0 | ||||
| Astigmatism | Low. | 7.5/10.0 | ||||
| Distortion | The distance of the first curved line from the field centre compared to the field of view radius: 44% +\- 5% | 4.5/10.0 | ||||
| Coma | Medium. | 4.8/10.0 | ||||
| Blurring at the edge of the FOV | The blur occurs in the distance of 88% +\- 4% from the field of view centre. | 7.5/10.0 | ||||
| Darkening at the edge the FOV | Slight. | 3.7/5.0 | ||||
| Whiteness of the image | Minimal cream. | 4/5.0 | ||||
| Collimation | Exemplary. | 5/5.0 | ||||
| Internal reflections |
|
3.6/5.0 | ||||
| Housing | Solid, with significant weight but compact and great to hold in your hand. Good quality rubber, regulated eyecups with too much grease. | 7.5/8.0 | ||||
| Focusing | Comfortable central screw (480 degrees) an individual focus joystick. Nothing moves outside. | 4.8/5.0 | ||||
| Tripod | Brak. | 0/3.0 | ||||
| Interpupilary distance | from 57 to 73mm | 4/6.0 | ||||
| Closest focusing distance | 2.35 m. | 1.5/2.0 | ||||
| Eyepieces FOV | Apparent field of view of 64.4 deg (according to simple formula) and 58.7 deg (according to tangent formula). | 13/20.0 | ||||
| Field of view | Measured by us amounted to 6.54 +\- 0.03 degrees and was a bit wider than in the specifications. Wide field of view for this equipment class. | 7/8.0 | ||||
| Quality of the interior of the barrels | Inner tubes and the bottom black and matt. Minimal specks of dust on the prisms. | 4.4/5.0 | ||||
| Vignetting |
OL: 1.2%, OR: 5.9%. |
4/8.0 | ||||
| Prisms quality | High quality BaK-4. | 8/8.0 | ||||
| Antireflection coatings | Orange-purple on the objectives. Purple on the prisms. Green-purple on the eyepieces. | 5/5.0 | ||||
| Warranty [years] | 30 years. | 5/6.0 | ||||
| Final result |
72.2%
22nd place in the overall ranking of the 10x42 binoculars test. |
137.2 / 190 pkt | ||||
| Econo result | 36th place in the econo ranking of the 10x42 binoculars test. | -1.2pkt. |
Summary
Pros:
- wide field of view,
- very solid housing,
- field of view sharp even at the edge,
- low astigmatism,
- slight chromatic aberration,
- high quality of prisms and coatings,
- good transmission,
- correct blackening inside the inner tubes,
- good warranty conditions.
Wady:
- egg-shaped pupils,
- lack of tripod exit,
- a bit too high distortion.
A next set of binoculars which, along with the Docter and Ecotone SR-4 creates a group of triplets, very similar when it comes to the look, parameters and test results. However, the Discoverer stands out against the others because of the best sharpness at the edge and the wide field of view - the device should be certainly praised for it. On the other hand, though, it also has the most truncated exit pupils which influence the amount of gathered light. It’s a pity – if the exit pupils had the right shape and if the device had a tripod exit, the Discoverer would be one of the hits of our test. Even with these flaws, the product is still worth recommending.
The price of that product might be another problem. In the USA it costs about 350 USD. You can legally import it to Poland buying it in an American shop online for about 1500 PLN, the costs of transport, duty and the VAT tax included. That amount is significantly lower than 2375 PLN – a price suggested by the Polish distributor. With the lower price tag it would be undoubtedly one of our favourites here.
