RangefinderHumans interpret three dimensional shapes and tell distances by using the image difference between what's seen by the left and right eyes.Warships also use the image from left and right lens of their equipped stereo rangefinder to calculate distance to their targetThis way, it will be more accurate!Around 15 metresThe width of Yamato's rangefinder equipment reached 15 metresAccuracy increase along with the distance between the left and right lens… so if you have it like Musashi here, the accuracy will be higher.
Actually the distance between both windows and the magnification factor of the lens, called the "effective base length". See also, German's optical rangefinder.