30mm vs 34mm

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Batman13

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Hey

I am in the market for a new scope and have been looking at ones with a 34mm main tube. Since everything I own has a 30mm tube I was wondering what the pros and cons of a 34mm main tube where.


Cheers
 
Batman13 said:
Hey

I am in the market for a new scope and have been looking at ones with a 34mm main tube. Since everything I own has a 30mm tube I was wondering what the pros and cons of a 34mm main tube where.


Cheers
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The only real advantage is elevation adjustment. The disadvantages are weight and size.
 
Also typically a big price jump from 30 to 34mm. Comes down to, as always, what are you doing with the setup?
 
Main advantage is internal reticle movement is generally more in the 34 mm tube. There is no more light transmitted in a larger tube, that is determined by the objective lens size, quality and coatings. To a smaller degree, the larger tube has more area for the rings to grip so there is less chance of movement under recoil.
 
There is another advantage, the intermediate element lenses are larger so focal distance points are longer and easier to focus on the next element without having to resort to large lens curavtures... those curvatures and focal points are critical for not introducing distortions.
 
Got Juice? said:
There is another advantage, the intermediate element lenses are larger so focal distance points are longer and easier to focus on the next element without having to resort to large lens curavtures... those curvatures and focal points are critical for not introducing distortions.
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This would be true if the erector tube lenses were larger in diameter in the 34mm than in the 30mm. But if they were much bigger in a 34mm tube, wouldn't the elevation travel be equally limited as compared to a 30mm? In other words, wouldn't the erector tube movement would be limited by the same lack of space within the main tube?

Having the lenses spaced farther apart certainly enables the use of flatter lenses due to less light compression. It's why short scopes have their challenges.

Edit: I see you were taking about the fixed intermediate lenses. Yes, you are correct.
 
propliner said:
This would be true if the erector tube lenses were larger in diameter in the 34mm than in the 30mm. But if they were much bigger in a 34mm tube, wouldn't the elevation travel be equally limited as compared to a 30mm? In other words, wouldn't the erector tube movement would be limited by the same lack of space within the main tube?

Having the lenses spaced farther apart certainly enables the use of flatter lenses due to less light compression. It's why short scopes have their challenges.

Edit: I see you were taking about the fixed intermediate lenses. Yes, you are correct.
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LOL, all good. This was explained to me by an optics manufacturer once. Easy to see when you have all the lenses and a single point light source to test convergence etc
 
There is virtually no advantage in light transmission through a bigger tube as can be seen by the human eye. The objective lens size is the main factor in gathering light. The size of the other lenses within the tube and eyepiece have an insignificant effect on how much light is transmitted. Coatings are more paramount.
 
propliner said:
There is virtually no advantage in light transmission through a bigger tube as can be seen by the human eye. The objective lens size is the main factor in gathering light. The size of the other lenses within the tube and eyepiece have an insignificant effect on how much light is transmitted. Coatings are more paramount.
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but there is an advantage in focusing.
 
propliner said:
Yes, focus has a longer range both because of lens size and distance between them. Resolution and clarity are better too, but neither of these can usually be easily detected.
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depends on how acute one's vision is. Certain scopes will never ever sit on my rifles whilst others are welcome. The resolution and clarity after 8-9 hours in a varmint field means no vertigo/scope eye/headache after an intense session.

This is of particular importance at ranges beyond 200m
 
Got Juice? said:
depends on how acute one's vision is. Certain scopes will never ever sit on my rifles whilst others are welcome. The resolution and clarity after 8-9 hours in a varmint field means no vertigo/scope eye/headache after an intense session.

This is of particular importance at ranges beyond 200m
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You can certainly get spoiled by good glass. Overall, in terms of picture I think good lens geometry and coatings are more important than tube size. A premium 30mm-tubed scope will outshine many of the 34mm contenders given the same objective size. That being said, aside from some Chinese and Philippine newcomers, most of the scopes built that do have 34mm tubes are of the highest quality already, so competition is stiff.

I used a Zeiss Victory 6-24x56 with 30mm tube for a couple of years and it was hard to beat by any standard except for its weak elevation travel. I suspect they used too large of lenses in the erector. I now have some 34mm-tubed scopes and they have their advantages, but not necessarily for brightness or clarity. Turrets and elevation are the main reasons for me.

I prefer a 1" or 30mm-tubed scope on a hunting rifle for most all practical hunting purposes due to size, weight and cost. Long range? 34mm all day.
 
propliner said:
You can certainly get spoiled by good glass. Overall, in terms of picture I think good lens geometry and coatings are more important than tube size. A premium 30mm-tubed scope will outshine many of the 34mm contenders given the same objective size. That being said, aside from some Chinese and Philippine newcomers, most of the scopes built that do have 34mm tubes are of the highest quality already, so competition is stiff.

I used a Zeiss Victory 6-24x56 with 30mm tube for a couple of years and it was hard to beat by any standard except for its weak elevation travel. I suspect they used too large of lenses in the erector. I now have some 34mm-tubed scopes and they have their advantages, but not necessarily for brightness or clarity. Turrets and elevation are the main reasons for me.

I prefer a 1" or 30mm-tubed scope on a hunting rifle for most all practical hunting purposes due to size, weight and cost. Long range? 34mm all day.
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Excellent summation.
 
I had a Vortex AMG for a little while with a 30mm tube. It was as good or even better than a few high end 34mm scopes I had on hand at the time as far as brightness and the other pertinent standards we look for in a quality scope. I think the 34mm scopes have become the standard out of ease of manufacturing. It’s a lot easier to cram the magnification and travel while keeping the durability high into a 34mm tube. Turrets fall under the same theory. It’s a lot easier to stuff a minivan full of features and accessories than it is a two seat roadster.
As long as size and weight keep being accepted, tube and turret size will keep growing. I’m seeing 36 and 40mm stuff more often now.
 
I own 6 S&B PMll scopes, all are 34mm, myself maybe i am wrong but i do associate 34mm with top notch scopes.
 
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