Looking at Leupold specs, it appears that they have 1" glass in a 30MM tube.
Butch

What size glass is supposed to be in there? The lenses have to be mounted inside the tube body and inside the erector tube...and the erector tube has to be small enough to move up and down and side to side inside the body.

Butch, so do the european scopes. It is actually not 1" glass. The lenses are sized for the design of the scope and not for the diameter of the tube. The design is predicated more on the objective lense diameters, the length of the scoope, power and a number of other times but not the tube diameter. The 30mm just gives them more windage and elevation.

The reason that I ask is a Leupold 30mm 4x12 and a European 30mm is a 3x12. I am speaking tube size not glass size. It seems that Leupold variables are 3 times the power and the Europeans are 4 times. Does this make sense?
Butch

quote:

Originally posted by butchlambert:
The reason that I ask is a Leupold 30mm 4x12 and a European 30mm is a 3x12. I am speaking tube size not glass size. It seems that Leupold variables are 3 times the power and the Europeans are 4 times. Does this make sense?
Butch

No, Butch it doesn’t make any sense. Maybe its me, but I haven’t got the slightest clue as to what you are talking about or referring to.

What I'm refering to is that Leupold is using the same internals of their 1" scope in a 30MM tube as a marketing ploy. I just wonder if this is true and if anybody knows for sure? Not throwing any stones, just heard rumors of this and would like to know.
Butch

quote:

Originally posted by butchlambert:
What I'm refering to is that Leupold is using the same internals of their 1" scope in a 30MM tube as a marketing ploy. I just wonder if this is true and if anybody knows for sure? Not throwing any stones, just heard rumors of this and would like to know.
Butch

Why would this be a marketing ploy?

As Customstox has already pointed out, all a 30mm tube is going to give you is a slightly larger space for the erector tube to move inside the scope, which in turn means you will have a slightly larger range of adjustment.

If they increased the size of the lenses inside the 30mm tube that larger adjustment advantage would disappear since they would also have to increase the diameter of the erector tube to accommodate the larger lenses.

I don’t know this for a fact, but I would bet that the diameter of the European lenses inside the erector tube are the same size as the Leupold...and I don’t know what difference it would make anyway. The light entering and exiting the scope has nothing to do with the size of the lenses in the erector tube. The light passing through a scope is not “squeezed†down by the diameter of the tube body.

As far as a marketing “ployâ€...what would be the “ploy?â€

As far as a marketing ploy goes wouldn't it be easy to charge a lot more money if they have the same internals as a 1" in a 30MM tube? People think that the 30MM tube has some magic. So what we are saying is a 30MM tube allows more vertical and horizontal travel only? If that is the case both the Europeans , Leupold, and others are doing it for the same reason. I'm certainly not arguing with you as I don't know. I would like to learn a little more about scopes rather than just keep on paying a lot of money for something that I don't need.
Butch

Butch,

The only advantage to a larger scope tube body is that it allows more room for the internal mechanics of the scope, it has nothing to do with the optical quality or brightness.

Transmitted light and the size of the exit pupil are a product of objective lens size and magnification, not of tube body diameter.

People who think a larger tube body has any effect on quality or brightness don’t have a very good understanding of the physics of light or of the construction of rifle scopes.

Having said that, a 30mm tube body certainly doesn’t adversely effect quality or brightness either, so judging a scope solely on the size of the tube body is a silly exercise at best. Also, most of the newer scopes with these huge objective and ocular lenses would look pretty silly with a smaller diameter tube body.

What I look for in a scope is resolving power, because that is entirely a function of quality glass, quality coatings, and precise construction. Unfortunately, allot people LOVE whiz-bang gimmicks and the scope manufacturers are in business to sell scopes, so newer scopes are including more and more features and gimmicks that have very little to do with the actual optical performance of the scope. Some of these things are handy, and even useful (side focus for example), but their purpose is not the optical quality of the image that you see.

Leupold may be using the same internal mechanics for both scopes, but just like the other brands, they also include their best glass and coatings on their higher end models which is going to raise the price.

The last time I talked to Leupold they said that all of there 30mm tube scopes have 1" internal lenses.

We all know what Leupold has, they advertise it..

What size is the glass in a Euro 30mm tube.

Rich

Guys, it doesn’t make any difference what size the lenses inside the erector tubes are. You can’t put 1 inch diameter lenses inside of a 1 inch outside diameter tube body, and you can’t put 30mm diameter lenses inside of a 30mm outside diameter tube body. Obviously, the tube body has a certain wall thickness, and so does the erector tube.

A scope is a tube within a tube, and the inner tube (erector) holds the lenses and also has to be able to move up and down and side to side inside the outer tube (the body).

If you increased the diameter of the erector tube so it would hold larger lenses you would negate the advantage of having more room for internal adjustments, which is the only advantage in the larger diameter tube bodies.

Butchlambert seems to be under the misimpression (frequently fostered by the advocates of one or another scope make or type) that the larger tube allows a greater range of magnification "zoom". This is nonsense. Any scope could be made to zoom from zero to as high as you want to go, but eye relief would vary wildly.

In practical terms, variable power rifle scopes can zoom at about a 3/1 ratio (or slightly less) without adversely effecting the sight picture and eye relief. Some scopes advertise a greater ratio. Those that advertise a greater ratio fall into two categories, (1) those that lie about their magnification (as most do) and (2) those that actually have an extended range of magnification, but also have eye relief that varies too greatly to utilize the extended zoom.

The actual "zoom" of a Leupold Vari-X II 3-9X, a scope that is often used as a known standard for comparing other scopes, is actually 3.3x-8.6X, or a ratio of about 2.6X. Very few scopes of any size or type will significantly exceed that ratio without adversely affecting the scope's usefulness.

quote:

Originally posted by Stonecreek:
Butchlambert seems to be under the misimpression (frequently fostered by the advocates of one or another scope make or type) that the larger tube allows a greater range of magnification "zoom". This is nonsense. Any scope could be made to zoom from zero to as high as you want to go, but eye relief would vary wildly.

In practical terms, variable power rifle scopes can zoom at about a 3/1 ratio (or slightly less) without adversely effecting the sight picture and eye relief. Some scopes advertise a greater ratio. Those that advertise a greater ratio fall into two categories, (1) those that lie about their magnification (as most do) and (2) those that actually have an extended range of magnification, but also have eye relief that varies too greatly to utilize the extended zoom.

The actual "zoom" of a Leupold Vari-X II 3-9X, a scope that is often used as a known standard for comparing other scopes, is actually 3.3x-8.6X, or a ratio of about 2.6X. Very few scopes of any size or type will significantly exceed that ratio without adversely affecting the scope's usefulness.

Very good post.

Optics are one of those things where whenever you gain something in one area you lose it in another, and there ain’t no free lunch!

Stonecreek,

In your experience, exactly how is the "usefullness adversely affected" of Swaro Z6's, IOR's and USO's with 5-6:1 zooms; the plethora of S&B, Zeiss, etc, with 4:1? You mention eye relief varying greatly, but the above scopes usually have more nearly constant eye relief than a Leupold. What are the problems you've actually found with these scopes? Or have you found them all to by lying?

As to the tube size question, some here are quite mis-informed. Quite a few of the Euro scopes really do have larger erector assemblies containing larger lenses. And yes, larger internal lenses can make a difference. Specifically,



Look it up and learn.

quote:

Originally posted by Jon A:
As to the tube size question, some here are quite mis-informed. Quite a few of the Euro scopes really do have larger erector assemblies containing larger lenses. And yes, larger internal lenses can make a difference. Specifically,



Look it up and learn.

And what exactly is the “difference†that they make?

What, too lazy to look it up? The above was a historical reference, one of the first to emperically define the relationship between lens diameter and the resolution it is capable of transmitting--even with "theoretically perfect" lenses. The point being, even when using top quality glass, coatings, etc, larger diameter lenses will likely provide a better image quality when all else is equal.

Scopes have lots of lenses inside, including some very, very small ones:



Another mm or two really increases their size by a large percentage. When you see a European scope with a 30, 34 or 35mm tube and it has less elevation adjustment than a 1" Leupold, that might be a hint that all is not equal.

JonA,

You have demonstrated that you know how to cut and paste mathematical formulas and pictures from the interent, now could explain how that formula provides the empirical evidence that you refer to?

Keep in mind that the discussion is in regards to the lenses “inside†of the erector tube only, not the objective or ocular lens groups inside those larger diameter areas of the scope.

The above was just a simple example of an easily understandable case where larger lenses have more potential on paper, meant to jump-start peoples' own curiosity into the subject. Ask the same question about larger objective lenses here and you'll have 100 people jumping into the thread saying they don't matter at all except for providing a bit brighter image in low light--a quick search will show you plenty of examples.

Of course how the erector lens size relates is much more complicated which goes even way beyond the theoretical--manufacturing realities of equaling lens quality in a smaller size, coatings that don't work the same for every angle of incedence, the inherent increase of aberrations due to more highly curved surfaces required to go down to a tiny erector system from a big objective then back up to a large ocular group and , etc.

It was not my intention to imply there was a single, easy equation to explain it all but the opposite--to hint it really is more complicated than "doesn't matter" generalizations.

You said it doesn't matter at all. Your turn to demonstrate. Looking at the above scope, if it didn't matter at all they could sure make those lenses smaller. Make the whole assembly smaller. It would be lighter, cheaper to manufacture and offer a greater range of adjustment. It would reduce inertial forces of recoil and make the scope more durable. It would allow even smaller tube sizes, further reducing weight.

Sounds like a win, win, win, win all the way around. If it could be done without paying a penalty in optical quality, why aren't they doing it? Why are some of the very top optics in fact, moving farther away from this by increasing the size of the internals?

Don't take the above the wrong way, I'm genuinely curious. I don't know everything, I'm here to learn like everybody else. If you have a good answer to all of the above I will thank you...as I don't seem to remember as much about this stuff as I thought I did.

The problem with your formula is that it is used to measure the “theoretical†resolving power of a single lens, NOT a lens system.

In the formula for measuring the theoretical resolving power of a lens system (like a rifle scope) the letter ‘D’ stands for the diameter of the objective lens...not the diameter of the many other lenses inside the tube.

The sophisticated machines used to test optical instruments, using MTF (modulation transfer function), measure the entire spectrum of light waves entering and exiting the system. The machines are capable of excluding the human eye from the equation and they can measure slight differences that no human being could ever hope to perceive.

As I’m sure you are aware of, optical designers design their instruments with multiple lenses working together and complementing each other as a unit...not as single lenses.

If you want to buy a scope based on tiny “theoretical†differences measured by a machine that are not perceptible to your eye then I guess that’s up to you.

For the rest of us, the only practical and perceivable difference between a 1 inch tube and a 30mm tube is that the larger tube provides more space for internal elevation and windage adjustments, which is a mechanical advantage not an optical one.

I agree with you 100% that optics are a very complicated topic, but there comes a point when you have to separate the “practical†from the “theoretical.â€

quote:

Originally posted by fyj:
If you want to buy a scope based on tiny “theoretical†differences measured by a machine that are not perceptible to your eye then I guess that’s up to you.

Apparently you didn't read my mentioning the formula applying to objectives (yes, it was a poor example) and all the other real, practical reasons they can make a difference listed in my last post.

Have you ever looked through a 35mm IOR Tactical, 34mm Schmidt & Bender, big Hensholt, etc? Who says people can't see a difference?

JonA,

So, according to your theory you are saying that these particular scopes display a perceptible superiority in resolution solely because of the larger tube body diameter and/or larger diameter internal lenses?

I assume, based again on your theory, that the 35mm IOR scope had perceivably better resolution than the smaller 34mm S&B???

Larger diameter tubes, allowing for more internal adjustments, are a totally sound and practical idea on a tactical scope intended for use at extremely long ranges...but that has little to do with the topic we were discussing which was 30mm Leupold scopes using “1 inch glass†as a “marketing ploy.â€

The best apples to apples comparison I can think of is an IOR 35mm vs. 30mm or a S&B 34 vs. 30 so it keeps the glass and coating quality the same. I'll be doing it shortly as soon as my 35mm IOR shows up but I have no reason to believe all the others who have compared the same already are just making stuff up.

No, I didn't buy it specifically because it had a 35mm tube in case you're wondering but for all its other features. I certainly won't be bothered by it though.

It'll have less range of adjustment than my 30mm's. So the only reason for a bigger tube being more range of adjustment is not the case here and that's certainly topic we're discussing and why Butch asked the question in the first place.

Let me see if I can word this in the way that I mean it. I'm certainly not looking for a piss fight. I wanted to know if a 30MM scope only had a larger tube only or did it have other things to make it optically better. I had heard and I guess Leupold confirmed this and that is they use the same internals as their 1" scopes optically. I thought this must be an advertising ploy as I didn't see that it was doing anything. The extra range of adjustment is only good for long range shooting.
I gather that some of the larger diameter scopes[European] have larger internal components that allow better optics and maybe less range of windage and elevation adjustment.
Butch

A guy should buy whatever he wants, and for whatever reasons he “believes.â€

Having said that, there are allot of assumptions being made and conclusions being drawn that have little or nothing to do with the optical physics regarding the size of lenses inside of a rifle scope and/or the size of the tube body.

FWIW, I copied this from the Schmidt & Bender web site:

“All PM II variable power scopes are built upon 34mm tubes to provide the maximum possible windage and elevation adjustments along with finer click stops. “

Funny, if this larger diameter tube body provided for better resolution wouldn’t one assume that the company would make note of this added advantage in their advertising????

quote:

Originally posted by butchlambert:
Let me see if I can word this in the way....

Yes, that’s how I understood your question, Butch, and it’s why I piped in. While I won’t say it’s impossible to put more than a 3:1 zoom in a 1†tube, it must be difficult as I can’t think of any that are more. So you were wondering why Leupold’s 30mm scopes still had the 3:1 while some other brands’ 30mms are 4:1 or even greater and if there was anything else different. I thought it was a fine question.

I do think your answer is that for Leupolds and probably a few other brands, they’re using the same internals so all you’re gaining is more adjustment and a stronger tube. But for some other brands you see they don’t have any more adjustment but do have things like higher zoom ratios, etc. For these I do think the possiblility of other optical advantages exists. All you can really do is try and find an apples to apples comparison and let your eye be the judge, which is what I’ll be doing—although, like I said that’s not my reason for buying it.

All that said, if it is a factor there are plenty of others that are certainly bigger. There’s lots of good glass out there in 1†tubes. There’s lots of really crappy glass out there in bigger tubes. It’s not an apples to apples world.

quote:

Originally posted by fyj:
there are allot of assumptions being made and conclusions being drawn that have little or nothing to do with the optical physics regarding the size of lenses inside of a rifle scope and/or the size of the tube body.

Yeah, like it absolutely, positively doesn’t matter at all. That’s a pretty strong statement. Don’t stop there, please. You’re making the assertion so please do explain why none of the other reasons I listed above can possibly apply. You must have quickly learned a great deal about something you didn’t realize existed just a couple of days ago.

quote:

Originally posted by fyj:
FWIW, I copied this from the Schmidt & Bender web site:

Actually, looking back, I think S&B might use the same size for 34 as they did for 30. Many of their 30mm tube scopes were seriously limited in elevation travel—which of course suggests they’re still bigger than would fit in a 1†tube which was the point in the first place. If that’s the case a comparison of those wouldn’t be possible as I don’t think they even make 1†variables anymore. You could always compare one against a 1†Leupold.

But if that’s what you’re looking for, some do mention it; Swarovski and Burris for example brag up optical improvements from the bigger tube. Feel free to say they’re wrong. Feel free to say those who have done comparisons with their own eyes are imagining things. But if you were looking to scientifically explain why there is no way possible it can make any difference, you’ve got a ways to go.

quote:

I thought this must be an advertising ploy as I didn't see that it was doing anything. The extra range of adjustment is only good for long range shooting.

That is more or less the practicality of it.

Warrior

Variable scopes change magnification through linear (fore and aft) movement of the lens groups in the erector tube, so I’m not sure why a larger diameter tube would have much bearing on this other than ease of manufacture.