7x50 is perfect for power and low light ,front lens diameter :by power =50 :7=just over 7mm and that's the max human eye pupil aperture that's all you need for low light.I have found 10x50 binoculars worked better than expected at night. Hard to point, but with ambient light, they see better than bare eyeballs.
7x50 is perfect for power and low light ,front lens diameter :by power =50 :7=just over 7mm and that's the max human eye pupil aperture that's all you need for low light.
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At low luminance (overall mean = 5.76 mm), five distinct groups of increasing age and decreasing mean pupil diameter were identified: (1) ≤21 years = 6.98 mm; (2) 21 to 25 years = 6.36 mm; (3) 25 to 43 years = 5.83 mm; (4) 43 to 52 years = 5.47 mm; (5) ≥52 years = 4.97 mm (p < 0.001)