Why do scope manufacturers make small objective (20mm) scopes with 30mm tubes?
For example:
Leupold Mark IV 1.5-5x20 MR/T, 30mm
Schmidt & Bender 1.5-4x20, 30mm
Zeiss VM/V 1.1-4x24, 30mm
Burris EuroDiamond 1-4x24, 30mm
Doesn't the smaller front objective negate the benefit of a 30mm tube?