Home Forums Hunting & Shooting Hunting Optics 30 mm vs 1"

Good article but nothing really new there.

Obviously, having a quality scope is important and understanding that high-quality glass (coatings etc) is not easy to manufacture was one of the main reasons I was always skeptical and bashing Tract Optics for spamming this forum with their junks products.

Clearly, two guys running a business out of their garage won't be able to source the best glass just to assemble it for cheap by the Chinaman. Why would any of the best manufactures ever sell their so hard to make high-quality products to someone just to undersell them right? Can you even imagine Zeiss, Swarovski or even MeOpta selling their best glass to some smartass at some huge discount?

Anyway, to wrap this up, and again, just for me personally, there is a benefit of using 30mm tube (or even larger) over a one-inch tube.

If that's not the case for you, and for those still in denial, stick to your one-inch tubes (or your iron sights) and I'm sure that your exit pupil will let you hunt in complete darkness with your one-inch tube LOL.

Given equal wall thickness, larger outer diameter adds strength. Of course weight and space are considerations in many applications, but the simple rule of wall thickness and outerdiameter holds true based on the elastic modulus.

You have your OPINION. Many of us here have cold, hard facts, and the FACT is that -- all else being equal -- a scope with a 30mm tube is NOT going to transmit more light than one with a 1" tube. .

It really isn't debatable, either. It's solid, demonstrable science.

The 30mm tube has some advantages, none of which are more light transmission; first, the 30mm tube of equal thickness is more rigid than a 1" tube. Second, they allow you to use lower rings with larger objective lenses again making a more rigid total package. The biggest advantage of them is the larger tube allows MORE elevation and windage adjustment. This is also why the really high-end tactical scopes are 34, 35 and 40mm tubes. I think US Optics even has 50mm tubes.

Disadvantages are more expensive, heavier and, in some cases, less pleasing to the eye.

The European scopes have had 30mm tubes mostly because 30 is a nice round number in metric. 1" is a nice round number in our system. 30mm sounds better than 1 3/16".

Since switching to a 30mm tube on my 30-40 Krag, I can see the bullet flying through the air!

Try that schit with a 1" tube fellas...

So if 30mm lets in more light, given identical objective lens, where does the extra light go that doesn't make it to the ocular lens in the 1" tube?

I currently have 4 30mm tubes and 1 34 mm tube, just traded one of my 30's off one of the cheap SWFA 1-4's so I have both 1" and larger tubes. Keep this in mind there shaky, the only reaction the light has with the sides of the tube is in the form of extraneous refractions that arise due to imperfections in the optics. Thus some light that enters the rifle scope is not focused as it is intended to be into the designed optical path. This extraneous or non focused light is simply not usable or detrimental and the tube is deliberately coated or baffles are inserted to absorb this optical noise.

At low illumination (before dawn and after dusk) there is an optimum scope magnification that produces an exit pupil size equal to the eye pupil. This optimum magnification increases with the objective diameter. A magnification below this value reduces the target size. A higher magnification reduces the pupil size, reducing image brightness and contrast. The size of the scope tube has nothing to do with image brightness.

http://www.highpoweroptics.com/optics-tutorial-i-55.html

but please don't be offended and keep up the good work as this place would not be the same without you and a few others like you. At times I am reminded of that movie "the burbs" here on the fire. On the other hand if your at all interested in a reasonable course of action then asking questions instead of asserting positions that you "feel" are right sometimes is wiser, but again you might be a democrat, so either way we cannot lose, comic relief or knowledgeable discussion both are worthwhile!

or have extraneous refractions of the brain.....

Sasha and Abby,

Is your local Swarovski rep still comparing a 30mm tube to a larger-diameter water hose?

I knew the advertising guy who came up with the "30mm tubes allow more light" quite well. He started the campaign in the early 1990's, convincing a generation of shooters that light was some sort of liquid that flowed like water through a hose. But it isn't. Instead light rays are bent by lenses, the reason the objective lens focuses the light entering the scope at a point in front of the erector lenses, well inside the interior dimensions of a 30mm tube.

The light rays then have to pass through the erector lenses, which are inside an even smaller tube inside the scope. In some (but not all) 30mm scopes, the erector tube is just as small as in a 1" scope--which is how 30mm scopes end up with more adjustment range.

The ad guy was FOS in a bunch of ways. He once bragged to me about how his custom .338-06 was the greatest plains-game cartridge ever, because he took it to Africa and killed four animals with one shot each. I replied that my wife had done the same thing with a .30-06. He blinked a little, then went on to tell me how his special handloading techniques boosted his .338-06's velocities to match the .3338 Winchester Magnum. I asked him about those special techniques, and he said he used special charges of a special powder. A few minutes later, however, he asked why the spent primers of his handloads sometimes fell out after firing a round.

His advertising claim of light acting like water through a hose was discredited (easily) within a couple of years, and Swarovski dropped the ad campaign. But apparently it still lives on among the minds of some shooters.

well!!!!

I had no idea that this would cause such an argument. I think MD explained it best.

I believe that for me I will be sticking to the 1" tubes. I appreciate the knowledgeable responses and the comic relief.

Again, a good article but nothing new in that and once again, does not prove that exit pupil size is somehow related to the light transmission.

We can argue here all year long but clearly, there are benefits to larger tubes otherwise companies like Zeiss would not use 36mm tubes (almost twice the size of a one-inch tube) for even close range 1-8 scopes as nobody needs a hundred inches of elevation in those scopes so clearly, working with bigger tubes (and more light inside the tube) has some benefits otherwise I'm sure Zeiss would make this scope with a much smaller tube to save weight and 50% of their expensive glass material becasue even one-inch tube can be made very durable.

So again, stick to your one-inch scopes because there are no benefits to anything bigger than that and you will be a fool to carry the extra weight around.

ShakyHands,

Your posts continue to become more entertaining.

Zeiss's own website specifically mentions, several times, the wide adjustment range of the 36mm tube.

It also mentioned 92% light transmission, as if that were exceptional. It is at the high end, but not unique to 36mm or even 30mm scope tubes. In the optics business, light transmission is measured with an integrating sphere, and a number of scopes have tested at 90% plus light transmission, including many with 1" tubes.

Keep 'em coming. We're rolling in the aisles.

There's only one way to be sure why Zeiss uses 36 mm tubes. And you're not.

Again, a good article but nothing new in that and once again, does not prove that exit pupil size is somehow related to the light transmission.

you have to be someone's sock puppet here just for entertainment purposes. Thank you for the laugh.

ShakyHands? More like ShakyLogic.

You seem to be stuck on the idea of there's "more light inside the tube" because the tube is bigger per se, and that simply isn't it.

Mule Deer, yes there is a wide adjustment range of the 36mm tube across the Victory line but based on your own interpretation, there is no benefit to that inside a 1-8 close range scope and I'm sure that Zeiss would choose a much smaller tube size for this scope specifically if there was no benefit to 36mm tube over one-inch tube other than the elevation adjustment benefits.

Additionally, again with all due respect, you were the one trying to convince me and others that it is not easier to "get behind" larger tube in comparable size scopes so I would suggest to stop adding wood to this campfire because your own credibility is being diminished.

No, you're not sure, you're guessing. Any manufacturer makes products for one reason--consumer demand.

But keep guessing, it's good entertainment for a Monday morning. Thanks!!

ShakyHands,

Good to know about my credibility!

From now on, whenever I write about optics I'll consult you. Thanks for the tip.

Again you believe it's the larger tube per se, and that's not it.

One of the easiest (if not the easiest) to "get behind" scopes around is the 6x42 Leupold, 1" tube and all.

I'm 30mm hole is a new handle for one of the previous idiots on the campfire, just not sure which one.