Lookin to get a new Leupold scope a VXIII 4.5-14x40mm they have 3 different models 2 have a 1 in. tube diameter the other has a 30mm My question is whats better and why? Doesone let more light in and make it brighter in early morning? Any help would be appreciated Thanks for your help.

You should check with Leupold on the construction of VXIII scope with the 30 mm tube. The reason I say this, is I had the 3-9 x 50 mm Euro model with the 30 mm tube and the internal part were the same as the 1” tube ( info I received from Leupold). They had made the 30 mm tube for European market and I’m not sure if this still applies on the internal parts. Personally I would get the 1” tube unless I was going to do long distance shooting...

Besides cost of a larger lenses, I don't see why 30mm isn't the standard. Its just better overall in alot of ways. That said, 90% of my scopes are 1". I buy and sell alot of used scopes, so 1" is what you usually see.