Technical details
| Closest focusing distance |
3 m |
| Eye relief |
17.6 mm |
| Objective diameter |
50 mm |
| Magnification |
7 x |
| Exit pupil |
7.1 mm |
Marine 7 x 50 Hydro, blue
BRAVE THE ELEMENTS
Exceptionally precise yet almost unbreakable, the PENTAX Marine was developed for especially demanding conditions. Its oil-filled compass is built into the eyepiece, and an advanced stabilisation system reduces unwanted vibration when viewing. Bearings are clearly readable in 1 degree steps, and the rangefinder reticle allows easy distance calculation of known objects.
Magnification
The first number in the product name is the magnification. The MARINE 7 x 50 Hydro for example, offers 7 times magnification, making your subject appear seven times larger compared to the
naked eye. Normally, the higher the magnification, the narrower the field of view. Continuous observation for long periods is best with magnifications up to ten times, any higher and keeping
the image steady becomes less easy.
Objective Lens Diameter
The diameter in mm of the front lens of the binocular, and the second number in the product name, so the MARINE 7 x 50 Hydro has an objective lens diameter of 50mm. The larger this number
is, the better the light gathering power of the binocular, particularly important for low light viewing. Binoculars with larger objective lens diameters are normally heavier, more bulky and
costly.
Eyepoint
The eyepoint is the distance between the viewers eye and the eyepiece lens, measured in mm. The larger this number is, the more comfortable the binocular for spectacle wearers. For a pair of semi-compact binoculars the eyepoint should be between 14 and 18mm, whilst for a full size pair such as the MARINE 7 x 50 Hydro, an eyepoint of between 15 and 20mm is usual. Spectacle wearers should insist on an eyepoint of at least 17mm to see the complete field of view.
