Difference between 1" and 30mm

[JSantoro]

Awww, hell...

[Jellybean]

Which companys are known to use 30mm tubes with the proper inernals? Ive been eyeing an Leupold VXR and they use 30mm tubes.

I too would be interested in knowing this- or how to find out.
Not just for Leupold-in general.

[Belmont31R]

Got it JSantoro, I was just introducing another fold.

Quality lenses, so I've heard, have more to do with better clarity/brightness.

Aside from that, I've looked thru some S&B glass, Zeiss, Nightforce and others, but the only time I've seen a difference is in really low quality optics (Nstar, Bushnell, Tasco and such) and that's only because I was switching back and forth at the fun store just to see if there was a difference.

From what I know on the subject glass is part of it but the coatings have more to do with it, and the coatings are very expensive on pricey optics because there is such a limited market for those products.

2nd pricey thing is the quality of the internal movements. One of the beefs I have with scopes on the cheaper side is tracking, crispness, and accuracy. A lot of cheaper scopes come 'close' to being true to their designation (1/4 1/2 .10). Obviously to get them spot on the law of diminishing returns comes into play, and it becomes very expensive to get them accurate every time.

I will say a gun store is not the place to be testing optics. I do think NF makes a really good scope but they are out matched by other brands which do cost more. Ive owned NF, shot other peoples, done tests with other members guns on the range. During daylight theres not too much difference in brightness, and NF is certainly a brand that does put some nice coatings on their glass. What I like about SB personally is during bright days against lighter backgrounds the image appears almost polarized where you don't get tons of glare but during low light they simply come alive. I was shooting with another member at dusk last year, and we each had a NF optic and I had a SB. The SB was simply way ahead when it came to picking out the target which was a black painted steel hanging target against a dark dirt background. The NF optics you could barely make out the outline of the target while my SB was still very bright and had no problem seeing the target.


And I think it has to do with getting used to the differences, and being able to pick them out. Obviously a quick look through isn't going to show it all.


The features we are seeing on newer scopes are things some other brands have been doing for a long time in some cases or came out with first. SB has had the Flash Dot system for a decade, and yet still it seems half the industry still can't get a day light visible dot in their scopes.




And yes this necro thread got a good lot of them.... Still good info though and food for thought.

[Belmont31R]

I too would be interested in knowing this- or how to find out.
Not just for Leupold-in general.

A Short-Dot has -1 to 25MOA of vertical adjustment once zero'd and all that. As far as total adjustment possible Im not sure.

[Zhurdan]

Belmont,
Nice part about my "fun store" is that it's kinda the only transfer point around here, so I spend a lot there. They give me the faux stock with the rubber cups and let me take the scopes outside. Not like I was staring at the far wall of the building or anything. There's still a difference to be noticed even in daylight between the high end stuff and low end stuff.

I wasn't staring at some stuffed mount in a Cabela's. heheheh

[Belmont31R]

Belmont,
Nice part about my "fun store" is that it's kinda the only transfer point around here, so I spend a lot there. They give me the faux stock with the rubber cups and let me take the scopes outside. Not like I was staring at the far wall of the building or anything. There's still a difference to be noticed even in daylight between the high end stuff and low end stuff.

I wasn't staring at some stuffed mount in a Cabela's. heheheh

I know Im just saying actual range time and use is best not casual gun store encounters.

[Bimmer]

1. A 30mm tubes will/won't pass more light than a 1" tube: This one is silly, but people argue it... of course a 30mm tube will "pass more light."

I don't think so...

Isn't a scopes ability to "gather light" related to its objective lens more than the tube diameter? Once it hits the first lens, it's being reduced, reversed, resized(magnified) and reversed again. Tube diameter, I'd think, is more related to the size of the internal lenses and their quality/size over light transmission. Just a guess from physics class.

I'm not a physicist, but this is my vague understanding... Since the light coming in the front of the scope is reversed upon itself by the convex front (objective) lens, the light really passes all through one point, so the size of the tube is irrelevant, it's all about the front (objective) lens.

[SomeOtherGuy]

Follow on question: per Burris advertising, a typical 1" scope tube will house 11mm internal lenses (I believe this is the focus lens and the image erector assembly) while a typical 30mm scope tube will house 15-15.4mm internal lenses:
http://www.burrisoptics.com/tech.html

So the internal lenses for a 30mm tube are roughly 36% larger diameter than for the 1" tube.

Lenses are, obviously, very precisely ground and finished. But there are limits to precision, and assuming that a given manufacturer and price point would use the same machinery to grind lenses whether they are 11mm or 15mm, then if a certain level of precision (WAG: 1/10,000") is possible, the 15mm lens can be expected to be about 36% closer to its intended profile than the 11mm lens, at the same level of precision. That in turn seems like it should improve many aspects of optical quality - resolution, crispness, uniformity from edge to edge, etc. It may also make it easier to prepare aspherical lens shapes rather than spherical ones, since the curve adjustments needed are 36% bigger.

I am not an expert on this so while I'm making a statement, it's intended as a question for anyone with expertise to answer. I know from experience that cameras and microscopes with larger diameter lenses are almost invariably higher quality optics than ones with smaller diameter lenses, but I don't know the extent to which that is a result of the diameter vs. the extent to which people willing to pay for quality are simply also interested in the larger diameter lenses for whatever reason.

[Bimmer]

... the 15mm lens can be expected to be about 36% closer to its intended profile than the 11mm lens, at the same level of precision...

I am not an expert on this so while I'm making a statement, it's intended as a question for anyone with expertise to answer.

AFAIK, this is pretty much a non-issue.

People talk about the quality of the "glass" or the "lenses," but for the last couple decades making top quality glass lenses has been easy and cheap.

What separates the good from the bad from the ugly scopes isn't the quality of the lenses themselves as much as the coatings (anti-reflective and anti-fog) and the assembly of the scope (the alignment of the lenses, for example).

So, given that it's not so tough or expensive to start with top quality "glass," it doesn't seem like making good lenses of 11mm diameter vs. 15mm diameter would be much of an issue at all.

[Hochsitz]

Without question a larger tube diameter allows for more adjustment range, but it can also be used to make room for things like a parallax adjustment mounted on the adjustment turret (side focus) or reticle illumination in the front focal plane. All that stuff takes room and can be a legitimate reason to use optics from a 1" scope in a 30mm tube.

On the topic of light transmission, anti-reflection coatings play a huge role, but so does the number of lenses and hence surfaces that reflect light. If the larger objective lens requires an additional lens behind it to do its job then the overall light transmission through the scope will be less. Your exit pupil will be larger but that's not what this thread is about. This is why it's SO important to get outside in LOW light when comparing optics. I see really expensive optics that look beautiful in the middle of the day because they have lots of lenses that produce a near perfect image. But take that same scope out as the sun goes down and compare it to a less expensive and lighter scope that's 10 years old and you may surprise yourself. Of course it all depends on the type of shooting you're doing. If you only go to the range and shoot in broad daylight then get the scope that looks the best under those conditions.