explain objective size to me again

[hofts]

i am considering a nightforce nxs 2.5-10x24 scope for a 270 wsm.

i have never had an objective that small, and think it will not let in enough light for very early morn and late evening hunts. this scope does have an illuminated reticle. will this let in as much light as my vx3 4.5-14x40? does a 4.5-14 x50 let in a lot more light than the other?

please advise

thank you.