kc
Well-Known Member
Is a 30mm diamiter better than a one inch diamiter?
Tube diamiter?
- Thread starter kc
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mackgee
Well-Known Member
The way I understand it, the only thing you gain from the 30mm tubes is you have more windage and elevation adjustment than you get with the 1 inch scopes. Other than that you don't gain anything else.
Mac
Mac
That's the way I also understand. Light gathering is not better with the same objective size.
bruce_ventura
Well-Known Member
To get 6X zoom range, I think you need to go to 30 mm.
LouBoyd
Well-Known Member
That appears to be true, but I'd bet it's more driven by marketing than optical design necessity.
bruce_ventura
Well-Known Member
Read recently that the reason is mechanical. A 6X magnification range requires that lenses in the erector tube move further than for a 4X range. The power ring translates lenses via helical slots.
A single rotation of the power ring on a 1" tube cannot move lenses far enough for 6X. The helix angle in the translation mechanism would be too steep, requiring excessive torque. The same rotation of the power ring on a 30 mm tube can, however.
A single rotation of the power ring on a 1" tube cannot move lenses far enough for 6X. The helix angle in the translation mechanism would be too steep, requiring excessive torque. The same rotation of the power ring on a 30 mm tube can, however.
Max Heat
Well-Known Member
The terms 4X and 6X are not really proper, in this context. It would be more proper to state it in terms of power adjustability (zoom) RATIO, as in 4:1 or 6:1.
... or simply X4 and X6! lightbulb
However, everyone seems to know exactly what it meant and responded accordingly.
Max Heat
Well-Known Member
That looks better I guess, being that it does not have the same appearance as magnification level. I'm not any sort of expert in optics or anything. In hindsight, I should have let it ride. What I just realized though, is that the magnification level itself is also a ratio. Only difference is that it is set "over" 1, instead of "to" 1.
davewilson
Well-Known Member
i have a scope ordered that has a 10x zoom range, it's a 30mm. the 30mm tubes are basically much stronger . most have thicker side walls and the bigger diameter helps too.
Max Heat
Well-Known Member
Out of curiosity, what is the zoom range and objective size on that scope?
davewilson
Well-Known Member
2.5-25 with a 42 bell
Colorado Cruiser
Active Member
- Joined
- Feb 10, 2009
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If all of the above is true, why does vortex use a 34mm tube in the razor and it is a 4X (5x to 20x)? Maybe light transmission??
bruce_ventura
Well-Known Member
It's actually a 35 mm tube. It gives a whopping 125 moa of reticle adjustment. I think it's all for product differentiation.
