But again neither one is superior to the other. For example, a 7x35 has an exit pupil of 5mm and a relative brightness of 25. Compared to a 7x42 with an exit pupil of 6mm and a relative brightness of 36. I mean it is merely stating the exit pupil in another way. It has nothing to do with light transmission or with image quality.
Resolution is the ability of a binocular to distinguish fine detail.
Resolution is greatly enhanced by higher quality lenses and prisms. It differs from relative brightness in that it takes the magnification of the binocular into account. By multiplying the power or magnification by the diameter of the objective lens and then taking the square of that product. A binocular that is 7x42 would equal a twilight factor of 17.2. However like our relative brightness this really doesn't mean much.