So looking at new binoculars. How much difference in light gathering capability would there be between a pair of EL 10 x 50's vs the NL pure 10 x 42?? Close in price..somewhat but the El's have a 5mm vs 4.2 eye pupil diameter. I know there is lots of difference in field of view. But old eyes need more light so thats my main focus in getting a new pair of binoculars.