TUBE DIAMETER

[W16OEN]

Hi Folks,

Could someone please explain the advantage of a 30mm tube over a 25mm. Is there a notable difference to the user?

I am aware that a larger objective diameter captures more light - does a larger tube transmit that extra light to the eye.

When a scope is termed wide angled, what gives it that wider vision?

Thanks

 

[willie_gunn]

Hi

Tube diameter is more about scope strength and adjustment (as in windage and elevation) than it is about light transmission. See Zeiss's very good explanation here:

http://www.zeiss.de/c1256bcf0020be5f/Contents-Frame/7e7e646ce8d7125e852575690054ef3a

This is why a lot of the tactical scopes come in 34mm tube diameter and larger - you get more adjustment capability.

Can't comment on the wide-angle question, other than that field of view and magnification work inversely - i.e. the larger the magnification the smaller the field of view and vice versa.

willie_gunn

 

[ejg]

30mm allows for more adjustment and for possibly stronger and chunkier adjustment mechanics. As mentioned 30mm is stronger stiffer than 25-26mm with the same wall section. I don't think it has any effects on the optical quality.
30mm scopes are mostly heavier. A few of us are slowly going back to 1" tubed scopes. Even schmidt and bender came out with a new light weight 1" scope "Summit" this year.
edi