Sea Tidbits: 7 × 50 model is generally considered the most suitable for astronomical observation binoculars, its exit pupil diameter of 7.1 mm, Jay and telescope imaging bright and clear monopoly, large field of view, generally 6 to 70, and light weight Jay and telescope stores, easy to hand observation. With increasing age, the maximum diameter of the pupil will be gradually reduced. 30-year-old is 6 mm, 40 years old generally only 4.5 to 5 mm. Then use the binoculars 10 × 50 of more appropriate. Exit pupil of the exit pupil refers to an image forming eyepiece premises. Exit pupil diameter (mm) is the effective aperture divided by magnification. Changes in the diameter of the pupil of the human eye to a range of 2-3mm dark day of 7mm. So exit pupil diameter, then 7mm, can get how large telescopes like Jay and brightness? Suitable for dark occasions. Taiyuan sea breeze Electronics Co., Ltd. The company was established in 2002, specializes in wholesale sales telescopes, binoculars, outdoor equipment. Company in good faith, customer-oriented objectives grown to thirteen brands Shanxi telescope first year. Jay and telescope manufacturers | yangqu Jay and telescope | sea breeze provided by electronic Electronics Co., Ltd., Taiyuan sea breeze. Taiyuan sea breeze Electronics Co., Ltd. (www.tyhfdq.com) strong, credible, in Taiyuan, Shanxi telescope industry has accumulated a large number of loyal customers. The company better work attitude and constantly improving innovative ideas will lead breezes into the brilliant electronic and you work for a better future!