Re: Why a 24mm objective?
there is an actual technical reason why. the reason is that with a specific objective focal length,you can't increase the objective diameter beyond a certain size without getting technical(read

ptical) problems,like more aberrations or increasing ray angles. in fact,every millimeter more can make it exponentially much worse. now,if you increase the starting magnification(like say 1.5x instead of 1x) you alleviate this technical problem and can make the objective larger.(making the objective diameter larger and the shape of that lens can also bring other negative "issues" but it can also give advantages)
second,don't be fooled by the numbers given(either by the manufacturer or the vendor)for the exit pupil at the lowest mag. many times the EP given for the highest mag is correct(but sometimes not) but the EP number given for the lowest mag is way,WAY off for the specs given on many scopes out there. regardless of what "experts" may say,it is not just simply a matter of dividing the objective lens size by the mag range and viola,you know the EP for every single scope out there. it doesn't matter how often this formula is repeated on the internet. however,some brands/manufacturers are actually giving you exact EP numbers on both low and high,but then sometimes within the same brand they are lying about the number on another scope,especially the low mag EP.
i don't consider myself a scope expert and i'm not an engineer.