Originally Posted by
Kodi
Bigcountry, Sorry, but I will rely on the optical experts from Leupold. This is directly from their website:
The Leupold Answer Guide
Advantages of a 30mm Maintube
Does a 30mm main tube give you more light? The principal advantages of the 30mm tube are added strength and increased adjustment range for windage and elevation. For example, the M8-12X (1" main tube) has a total elevation adjustment of 51 minutes. The Mark-4 M1-10X (30mm main tube) has 90 minutes. The percentage of light passing through a scope is a function of lens coating and optical design, and has nothing to do with tube diameter.
I assume that Leupold does have some valid expertise in scope design.
Go for it man. Have a ball.
Yep, thats straight out of Phyics of Light 101 book I studied 20 years ago in college. Almost word for word. But as usual, experience cannot be bought in this case. There is a lot more to it. With ideal lenses, and a perfect design, this is absolutely correct. Too bad ideal shaped lenses and medium are not cheap.
And you are missing a key component to leupold's answer. Guess what? They don't use 30mm lenses in any of thier 30mm scoped products. 1", just like thier 1" scope. But I guess you knew that. Think there would be any marketing advantage to exploit that 30mm internal lenses are no better than 1" internal? Think 1" lenses are 30% smaller polishing area than 30mm lense. Think there is any price advantage to exploit that 30mm internal lenses are no better than 1" internal?