Binoculars review
Opticron Countryman 10x42 BGA T
The Countryman series consists of three roof prism instruments with the following parameters: 8x42, 10x42 and 10x50. These are compact, physically light constructions, nitrogen-filled and waterproof down to a depth of three meters.
The producer informs us that in 2007 the series was improved by adding Oasis reflection coatings – one of the air-to-glass surfaces on the prisms was covered by them which is supposed to increase significantly the transmission level. As the specimen, tested here, was manufactured in 2006, it most probably doesn’t feature the new coatings (the average transmission results prove it too).
| Magnification | Lens diameter | Angular field of view | Prisms | Eye relief | Weight | Price |
|---|---|---|---|---|---|---|
| 10x | 42mm | 88/1000(5o) | BaK-4/roof | 18 mm | 650g | 1450PLN |
Results of the review
| Real front lens diameter |
Left: 41.27+/-
0.05mm Right: 41.23+/- 0.05mm |
4/8.0 | ||||
|---|---|---|---|---|---|---|
| Real magnification | 9.8+/- 0.2x | 3/3.0 | ||||
| Transmission | 72+/- 3% | 7/15.0 | ||||
| Chromatic aberration | Slight in the centre, higher at the edge. | 6.2/10.0 | ||||
| Astigmatism | Very low. | 8.1/10.0 | ||||
| Distortion | The distance of the first curved line from the filed centre compared to the field of view radius: 44% +\- 5% | 4.5/10.0 | ||||
| Coma | Very low. | 8.1/10.0 | ||||
| Blurring at the edge of the FOV | The blur occurs in the distance of 89% +\- 2% from the field of view centre. | 8/10.0 | ||||
| Darkening at the edge the FOV | Low. | 4/5.0 | ||||
| Whiteness of the image | Distinct pink-yellow hue. | 3.4/5.0 | ||||
| Collimation | Perfect. | 5/5.0 | ||||
| Internal reflections |
|
2.4/5.0 | ||||
| Housing | Solid but the rubber sticks out a bit. Grease on the bridge. Twisted-up eyecups. Good level of ergonomics. Slippery rubber. | 6.8/8.0 | ||||
| Focusing | Comfortable central screw plus a click-stop system. | 4.6/5.0 | ||||
| Tripod | The exit is not very convenient. | 2.5/3.0 | ||||
| Interpupilary distance | from 57.5 to 72.5mm | 3/6.0 | ||||
| Closest focusing distance | 2.5 m. | 1.5/2.0 | ||||
| Eyepieces FOV | Apparent field of view of 50.6 degrees. | 5/10.0 | ||||
| Field of view | Measured by us amounted to 5.16 +\- 0.04 degrees and was wider than in specifications. A narrow field of view for this class of equipment. | 5/8.0 | ||||
| Quality of the interior of the barrels | Black but the tube and the bottom are very shiny. Some isolated specks of dust. | 3.9/5.0 | ||||
| Vignetting |
|
6.5/8.0 | ||||
| Prisms quality | High quality BaK-4. | 8/8.0 | ||||
| Antireflection coatings | Greenish everywhere. Medium intensity. | 4.5/5.0 | ||||
| Warranty [years] | 10 | 3.5/6.0 | ||||
| Final result | 44th place in the overall ranking of the 10x42 binoculars’ test. | 118.5/170
69.7% |
||||
| Econo result | 40th place in the econo ranking of the 10x42 binoculars’ test. | -2.4pkt. |
Summary
Pros:
- physically light but solid casing,
- very low coma,
- very low astigmatism,
- sharp image almost in the whole field of view,
- low brightness loss at the edge of the field,
- good quality prisms.
Cons:
- narrow field of view,
- average transmission,
- left pupil is egg-shaped,
- too distinct flares,
- the objective lenses are closer to 41 mm than to 42 mm.
Let’s deal with the advantages first. The binoculars are undoubtedly solidly build and the overall impression is good – the device has a rich accessory kit and very good results in the case of main optical aberrations (coma, astigmatism, chromatic aberration). Its weak point is without doubt a narrow but sharp field of view, the reason why the instrument fares so well when it comes to the off-axis aberrations’ correction. It is much more difficult to correct these aberrations in a wide field of view than to cut out unwanted edges by narrowing it artificially. The tested binoculars have also a problem with coatings on both prisms and eyepieces. Their intensity is not very low for this price segment and it adversely affects the transmission, colours rendition and inner flares.
To sum up once again we witness a typical performance for an Opticron. Overall, the instrument is good but its price/quality ratio – just average. Taking into account the fierce competition in the 10x42 class we can certainly find many better devices similarly priced.
