The two numbers on a binocular tell you a lot. Enter the magnification and objective lens size to see how bright the view will be and what the binocular suits best.
Plan how much raw meat to buy and roughly how long the cook will take. Cook times are rough guides at 225–250°F; always cook to internal temperature, not the clock.
What the numbers mean
Exit pupil is the beam of light that reaches your eye, in millimeters. Around 5 mm and up stays bright at dawn and dusk; around 4 mm is a good daylight all-rounder.
Twilight factor is a rough guide to how much detail you can make out in low light. It favors higher magnification, so read it together with exit pupil.
Glass and coatings matter as much as the numbers. See birding binoculars, low-light binoculars and 8×42 vs 10×42.