The Soligor Black Line 7×50 is a classic Porro prism binocular offering 7× magnification and 50 mm objective lenses. It is suitable for viewing landscapes, nature and the night sky. The 7× magnification makes handheld observation easier.
The prisms are made of BaK-4 glass, and the optics feature multi-layer anti-reflection coatings (MC), which reduce reflections and help improve image contrast. The approximately 7.1 mm exit pupil supports low-light observation; making use of its full diameter depends on how far the observer’s pupils dilate.
• 7× magnification and 50 mm objective lenses
• Porro prism design with BaK-4 glass prisms
• multi-layer anti-reflection coatings (MC)
• exit pupil diameter of approximately 7.1 mm
• tripod mounting capability
• Soligor Black Line 7×50 binoculars
• neck strap
• objective lens and eyepiece covers
• carrying case with strap
landscapes
birds
hunting
aircraft
astronomy
• objective lens diameter: 50 mm
• magnification: 7×
• prism system: Porro
• prism material: BaK-4 glass
• exit pupil diameter: approximately 7.1 mm
• angular field of view: 7° (according to the Soligor catalogue)
• linear field of view: approximately 122 m / 1000 m (calculated for 7°)
• anti-reflection coatings: MC, multi-layer
• minimum focusing distance: 5 m
• weight: approximately 845 g
• tripod mounting capability: yes
• twilight factor: approximately 18.71 (calculated value)
Never look at the Sun through binoculars. Doing so can cause permanent eye damage or loss of sight.
PDF guides in Polish.
Choosing binoculars — a guide [PDF]
A short guide to cleaning optics [PDF]
What does 7×50 mean?
The first number indicates 7× magnification, while the second is the objective lens diameter of 50 mm. This model has fixed magnification.
What is included?
The set includes the binoculars, a neck strap, objective lens and eyepiece covers, and a carrying case with strap.
What are MC coatings for?
MC stands for multi-layer anti-reflection coatings. They reduce reflections from optical surfaces, limiting light loss and helping improve image contrast. The MC designation alone does not mean that all surfaces have multi-layer coatings.
Do BaK-4 prisms guarantee image quality?
BaK-4 denotes the type of glass used to make the prisms. Image quality also depends on the optical design, coatings, manufacturing precision and alignment of the optical components.
Are 7×50 binoculars suitable for twilight observation and astronomy?
Yes. They can be used for low-light observation, scanning the night sky and viewing larger star clusters. To take full advantage of the approximately 7.1 mm exit pupil, the observer’s pupils need to dilate to a similar diameter. A tripod helps stabilise the image during longer observing sessions.
How are exit pupil, relative brightness and twilight factor calculated?
The exit pupil is the image of the objective lens seen from the eyepiece side as a bright circle. For the nominal 7×50 specifications, the following values can be calculated:
• exit pupil diameter: 50 / 7 ≈ 7.14 mm, or approximately 7.1 mm
• relative brightness: (50 / 7)² ≈ 51.0
• twilight factor: √(7 × 50) ≈ 18.71
Relative brightness and twilight factor are calculated indicators. They do not account for light transmission or the quality of the optics.
