Oh, maybe not? I'm not throwing mine away, just yet. You still pay a premium for the 56MM objective, and perhaps the deciding factor is the tube size, one inch or 30mm? Another factor is your mission. Top quality optics should allow for almost any situation, during legal hunting hours, without the need of 50 or 56mm objective lenses. Hunting after dark is where the large objectives and 30mm main tubes excell, other than that, they may be too bulky and too expensive? Decide what you want to do and buy accordingly.
Good hunting. LB
edit: high magnification requires more light gathering, also, kind of like an f-stop on a camera.
...several things to consider... 56mm would obviously gather more light than the 50mm, with all other things being equal... must consider how important low light performance is vs the extra weight and height of the objective lens... have never felt deprived by 50mm lenses, in fact, prefer 44mm or thereabouts for most live hunting applications... also smaller obj lense puts the scope closer to bore, but I gotta admit, just one look through a large objective and it's really bright... ultimately it depends on the type of rifle it will be mounted on and your own personal preferences... I just love'em all!
No Need for a 56mm Obj for most applications, a human eye won't notice the difference between a 50mm and a 56mm. I'd go for the 50mm. Optical quality is the issue, you'd be better of with quality x42mm Obj than a crappy 56mm. NXS seem pretty good, you'd be better of with the 50mm.
In theory, with either scope, the 56mm will allow maximum light to reach your eye @ 9.3X, and the 50mm will provide the same amount of light when set on 8.3X.
Under dark conditions when you really need the maximum amount of light (6mm exit pupil) do you NEED more than the 8.3X that the 50mm scope provides? Probably not.
I'll go with the guys who recommend the 44mm objective scopes. They are smaller, lighter, less expensive and provide maximun light when set @ 7.3X. That is MORE magnification than I almost ever use in the field while hunting biggame.
Your origional question "what is better a50mm
obj.or a 56mm obj." my question is what are
you using it for ??? If I was packing it on
a light carry gun I would take the 50mm or
smaller (40mm),if it was on my 24lb. 1000yard
gun that I dont pack around give me the 56mm
or bigger (80mm).Quality of glass is an issue
also, on the Nightforce there might not be
that big of a difference between the two
because they use quality glass and it is only
6mm diference.if you take El Chinero quality
of glass it is junk if it is 40mm or 80mm.
You can take a Leupold 6.5x20 40mm and put
it next to a Leupold 6.5x20 50mmLR with the
30mm tube,in mid-day light you dont notice
that much difference but at dawn or dusk at
20 power absolutely no comparison the 50mm is
better it just all depend's on what your