Is it worth spending the extra money to get a 30mm tube. Is there that much difference in a 30mm vs. a 1"? Just what do you gain?

Well the increase in dia.will make it stronger,and the increase in mass will make it more prone to recoil damage.I have never had a 1" scope fail because of recoil.Some say there is more room for more adjustment in a 30MM Tube.I would stick with a 1" tube as I see no downside to them.I am not trying to start a war on Tube size.I just prefer the 1" tube. OB

the lenses in the 30mm are the same ones in the 1"

• A 4 times power multiplier
  
• Greater field of view
  
• Greater range of adjustment
  
• Stronger tube

What's not to like?

quote:

Originally posted by OLBIKER:
Well the increase in dia.will make it stronger,and the increase in mass will make it more prone to recoil damage.I have never had a 1" scope fail because of recoil.Some say there is more room for more adjustment in a 30MM Tube.I would stick with a 1" tube as I see no downside to them.I am not trying to start a war on Tube size.I just prefer the 1" tube. OB

To make a general statement that a 30mm scope is more prone to breakages because it is heavier than a 1" tube is incorrect.The top of the line tactical scope are 30mm to 35mm tubes and they are the toughest scopes cunrently being produce ( Nightforce,S&B PMll,US Optics,Etc.)

quote:

# A 4 times power multiplier
# Greater field of view
# Greater range of adjustment
# Stronger tube

Yeah their advantages can't be argued, I agree....but I still prefer the 1" tubes...course you see examples of fourfold power availability in 1" and adjustment range and strength have yet to become a deciding issue for me in my applications I guess.

woods

Not sure I'm tracking you. What does "A 4 times power multiplier" mean? With regard to a 30 mm tube vs a 1" tube?

TIA,

Don

1" tubes are generally 3x9's, 4x12's which takes the lower power and multiplies it by 3 to get the higher power. Some companies fudge and might call a 1" tube a 3x10 or a 4.5x14 but I suspect there is some fudging and rounding off going on there.

30mm tubes are generally 2.5x10's, 3x12's and 4x16's......you get the picture.

This held true until recently and now some companies like Redfield and Swarovski's have found a way to get higher multipliers.

BTW, I do not agree that the lenses in a 1" and 30mm are the same size. It has not been proven to me but I have seen informed opinions stated that have said otherwise. I do believe that Leupold cheated with their 30mm tubes by just using the same lenses but that does not mean that the much better optics companies (which includes just about every other one) have done the same.

Don't get me wrong, there are some excellent 1" tubes out there and I have a few but the 30mm tubes have the potential to be better (if you can get past your prejudices).

jwp475,You need to review your High School Physics.Look up mass and motion!!!!! OB

quote:

Some companies fudge and might call a 1" tube a 3x10 or a 4.5x14 but I suspect there is some fudging and rounding off going on there.

Actually sightron, nikon new monarchs, burris signiture selects, some pentax, and bushnell 4200's are offering 1.5x6 - 2.5x10 - 4x16 -6x24 - 8x32 scopes and I don't think there is fudging going on as you phrase it. Simply more than one optics maker has managed to do fourfold power change in 1" scopes.

quote:

but the 30mm tubes have the potential to be better (if you can get past your prejudices).

Here I don't see it as better in my case if I'm not encountering situations where I need the added strength and adjustment range provided by the heavier (in like model scopes) and fatter tubes. I don't argue their added benefit to one who may actually need it but I haven't......I prefer a 1" tube because its looks better to me when mounted, and will do all I will ask of it to this point in time.

woods

quote:

BTW, I do not agree that the lenses in a 1" and 30mm are the same size. It has not been proven to me but I have seen informed opinions stated that have said otherwise. I do believe that Leupold cheated with their 30mm tubes by just using the same lenses but that does not mean that the much better optics companies (which includes just about every other one) have done the same.

Full agreement on that

quote:

Here I don't see it as better in my case if I'm not encountering situations where I need the added strength and adjustment range provided by the heavier (in like model scopes) and fatter tubes. I don't argue their added benefit to one who may actually need it but I haven't......I prefer a 1" tube because its looks better to me when mounted, and will do all I will ask of it to this point in time.

Full agreement on that as well
I think 30mm tubed scopes have their place in the scheme of things especially where one hunts at night I just don't like their bulk and weight although 2 brands are excellent in that regard Zeiss VM and the Swaro PH, for the most part the rest are too heavy and I just don't care for a 20+ oz scope on a light or medium weight rifle and the way it affects handling . Those 2 don't give me any more benefit or at least a measurable benefit then their 1" little brothers for most normal American hunting situations.

quote:

Originally posted by woods:

• A 4 times power multiplier
  
• Greater field of view
  
• Greater range of adjustment
  
• Stronger tube

What's not to like?

Sorry, and I do not wish to be disrespectful, but this list is inaccurate in a number of ways.

1. "4 times power multiplier". The diameter of the tube has nothing to do with the power range of the scope. A 3/4" tube could be made to multiply 100 times, but optical and physical limitations having nothing to do with tube size make it impractical. The larger eyepiece that a manufacturer is willing to put on a 30mm tube (where it doesn't look so disproportional) is helpful in utilizing a wider power range, but the size of the ocular lens has nothing to do with the size of the tube per se.

2. Greater field of view. Nope, again FOV is unrelated to the size of the tube. It is a function of magnification and eye relief.

3. Greater range of adjustment. BINGO! This is the only real optical difference in that the lens which contains the retical can move further (provided it is no larger) inside of a 30mm tube than inside of a 1" tube. Unfortunatley, if the manufacturer's specs from Leupold are to be believed, their 30mm scopes offer no more range of adjustment than their corresponding 1" scopes, so why does that particular manufacturer bother?

4. Stronger tube. All other things being equal (thickness of walls and alloy of metal), this has to be true. But when did you ever break a 1" tube, except in a calamity that would have damaged a tube of any diameter?

A scope with a 30mm tube will usually be somewhat heavier than a one-inch tube. This is of no disadvantage in a stationary varmint rifle or in an unlimited target gun, but is obviously undesirable in most hunting guns. The heavier tube will also theoretically place more stress on the mounts, but good mounts can certainly withstand the inertia of a few more ounces in most instances.

There are a few applications where a 30mm tube has its advantages. If you have one of these applications, by all means consider one. Unfortunately, the typical shooter buys a 30mm tube for the same reasons that he might respond to an ad that promises to enlarge his penis; and similarly is more concerned about self-satisfaction rather than measurable performance.

Stone Creek , I wish I had the ability to express myself as well as you do.I agree with what you posted 100%. OB

Picky, picky, picky! Nit-picky!

I guess I should have put all the caveats in like "in the majority of cases" or "until recently" or "generally speaking" - GMAB

Saying that a 2.5x10x50 30mm scope does not have a larger FOV than a 3x9x50 1" scope is ludicrous. There are no direct comparisons between the 2 because the 30mm tube has a lower power and it will have a larger FOV.

For example the nearest I can come to a comparison is like the Swarovski 2.5x10x42 30mm scope and the Swarovski 3x10x42 1" scope.

The FOV on the 30mm is larger, naturally because of the lower magnification. Even at the highest magnification of 10x the FOV is larger in the 30mm, although I suspect the actual magnification may be different. They do round the numbers off.

Or how about the Zeiss 2.5x10x50 30mm scope as compared to the Zeiss 3x9x50 1" scope. I have both of these Zeiss's BTW. The Conquest is clearer and brighter than the much more expensive VM/V T*, one helluva scope. See, I'm not prejudiced against 1" tubes at all.

The FOV is greater with the 30mm tubes. Why? Because they make them that way (with the lower power range) and have up until now.

Is the 30mm worth the extra cash? Up until now, if you wanted the very best with the largest range of adjustment and largest FOV, it was worth it. If you wanted a scope just as clear and bright for a lot less money, then no, it's not worth it (just make sure and get a Conquest or Nikon and not a Leupold).

Flame away!

quote:

Originally posted by woods:
Saying that a 2.5x10x50 30mm scope does not have a larger FOV than a 3x9x50 1" scope is ludicrous. There are no direct comparisons between the 2 because the 30mm tube has a lower power and it will have a larger FOV.

It is impossible to say whether a 2.5x scope will have a larger or smaller field of view than a 3x scope unless one knows the eye relief.

For example, 8x binoculars with an eye relief of about .80" will have a similar field of view as a 4x scope with a 3" eye relief.

Again, the size of the tube is irrelavent to the field of view (and also irrelavent to the range of magnification of the instrument).

Just because manufacturers may tend to "make them that way" if they have one or another size tube doesn't make the tube size the controlling factor. That would be like saying that if you buy a hunting rifle with a 24" barrel that it will be a magnum caliber and if you buy a hunting rifle with a 22" barrel that it will be a standard caliber just because most manufacturers tend to "make them that way". Just as barrel length doesn't control chambering, tube size doesn't control field of view or range of magnification.

Stonecreek

I agree with your point even though I have not verified it myself. I will take your word for it.

However it would not be possible to call Zeiss and tell them you want a 1" scope in the same size as a 30mm scope and want the same FOV that the 30mm has. They will tell you they don't make it. Therefore the FOV for the 30mm scope "is" larger than the FOV of the 1" scope (at the lowest power setting).

"It all depends upon what the definition of "is" is." Who said that?

quote:

Originally posted by OLBIKER:
jwp475,You need to review your High School Physics.Look up mass and motion!!!!! OB

I know enough physics not to run a Toyota into a Mac truck.. The wieght of the scope will put more stress on the mounting system is true the part that the scopes don't hold up is not.........
Nightforce NXS scopes are designed and guaranted to withstand 1200 G's both positive and negative try that with your little frail scopes........ :

jwp 475, What I said is true,but I never said that 30MM tobes were no good.I said I had never had a 1" tube fail me and could see no advantage to a 30MM tube.I also said that this was MY OPINION.You dont have to agree with me.You are intitled to YOUR OPINION.You should always read for content,not what you want too see and hear!!! OB

quote:

Originally posted by OLBIKER:
jwp 475, What I said is true,but I never said that 30MM tobes were no good.I said I had never had a 1" tube fail me and could see no advantage to a 30MM tube.I also said that this was MY OPINION.You dont have to agree with me.You are intitled to YOUR OPINION.You should always read for content,not what you want too see and hear!!! OB

This is what you said;

[Quote]
Posted May 7, 11:17 AM Hide Post
Well the increase in dia.will make it stronger,and the increase in mass will make it more prone to recoil damage.I have never had a 1" scope fail because of recoil.Some say there is more room for more adjustment in a 30MM Tube.I would stick with a 1" tube as I see no downside to them.I am not trying to start a war on Tube size.I just prefer the 1" tube. OB
[Quote]

I never disagreed that you never had a 1" tube scope fail on you.You stated that the 30MM tube scope was heavier and more prone to fail because of recoil.I responded that to make a broad statement such as that was NOT CORRECTED, becaues the toughest scopes made are the Tactical scopes with 30 and 35 MM tubes such as NIGHTFORCE,S&B,US OPTICS,ETC. Now this is not an opion this is A FACT
Now I typed this slow so that you can grasp it........You read for content and try to grasp the concept.............

The main reason you might go with 30mm Scopes vs 1" is that they are usually better optically. I was surprised that the earlier poster said that his 1" conquest was brighter and clearer than his 30mm tube scope. My experience has been that within the same brand the 30mm scope is better optically.

Not all 30mm tube scopes are that heavy. Some 30mm scopes are actually lighter than some 1" scopes of the same magnification. Swaro and Zeiss have some light 30mm tube scopes that are superb. S&B's are superb scopes but they are usually heavier.

If you can spend a good bit of time looking through the scopes you are considering. Preferably in the evening. If you are inside a store look into a dark corner or back room and try and pick out details. Sometime you can really see a difference in resolution even with such a simple test.
Good luck!....................DJ

Gentlemen,

Field of View has NOTHING to do with eye relief!

The field of view of the scope is simply the apparent field of view (defined by the eyepiece) divided by the magnification. It is possible to design wide field of view eyepieces with long or short eye relief. Practical physical limitations (i.e. the physical diameter of the eyepiece lenses) make it more difficult to get wide apparent field of view and long eye relief, but eye relief by itself is not a limitation.

Andy

I've always believed its the ocular size that effects FOV......the tube size that effects adjustment range......that strength was a result of tube thickness,material and diameter.....and optical quality is a direct result of lens quality,polishing,light correction,impurities in the glass,and the quality and number of coatings.

woods

quote:

Originally posted by butchloc:
the lenses in the 30mm are the same ones in the 1"

I thought the new Leupold V7 series of scopes, most particularly the 1.5 X 6 had larger objective lenses than the equivalent 1" tube. This model has a 24mm objective lens compared to the 20mm of the VX-III line. It also has 4X magnification. It's a 30mm tube.

quote:

Originally posted by Wink:

quote:

Originally posted by butchloc:
the lenses in the 30mm are the same ones in the 1"

I thought the new Leupold V7 series of scopes, most particularly the 1.5 X 6 had larger objective lenses than the equivalent 1" tube. This model has a 24mm objective lens compared to the 20mm of the VX-III line. It also has 4X magnification. It's a 30mm tube.

I just bought a VX-7, 1.5 to 6x and it has a 24 mm objective. I compared it to 8 other scopes I have, including other Leupolds, and the image is stellar, far better than any others I have. All were compared at the same power setting.
If you want to look through a great scope, look through a VX-7 some day.
This scope has a 30 mm tube.

Don

quote:

Originally posted by BigJakeJ1s:
Field of View has NOTHING to do with eye relief!Andy

quote:

Originally posted by BigJakeJ1s:
Field of View has NOTHING to do with eye relief!

Technically it may not but in practical terms it sometimes does. Leupold scopes for a good while tended to have longer eye relief than many of their competitors, they also had smaller FOV's. This may be the source of some of the conventional wisdom that long eye relief shortens FOV but Intermediate eye relief scopes and pistol scopes also have very restricted FOV's.
Maybe you could make a Pistol scope with a huge Occular and still have a normal sized FOV but in practical terms it's not going to happen. So in some cases Long Eye relief DOES mean a restricted FOV. Look through any Pistol or Scout scope and you'll see for yourself................DJ

Benefits of tube size may vary, however some thinkers not only see benefit in 30mm tubes, but even suggest that 34mm tubes might be advantageous.

It just depends on your particular desires, although this 34mm scope has a 5 to 1 zoom and a heavier wall thickness. Rifle still weighs the same as when the all steel Unertl M40 was on it.

quote:

Originally posted by djpaintles:

quote:

Originally posted by BigJakeJ1s:
Field of View has NOTHING to do with eye relief!

Maybe you could make a Pistol scope with a huge Occular and still have a normal sized FOV but in practical terms it's not going to happen. DJ

I think I just said that. People are willing to live with huge objective lenses, but for some reason are not willing to live with similarly large eye lenses that could afford (if properly designed) much wider field of view.

Andy

quote:

Originally posted by Stonecreek:

It is impossible to say whether a 2.5x scope will have a larger or smaller field of view than a 3x scope unless one knows the eye relief.

...

Again, the size of the tube is irrelavent to the field of view (and also irrelavent to the range of magnification of the instrument).

The size of the field lenses, which may or may not be limited by the size of the tube and the room left for adjustment, does affect field of view.

It is impossible to know whether a 2.5x scope has a wider field of view than a 3x scope, even if you know the eye relief! Just because one scope has a longer eye relief than another does not mean it will have a narrower field of view. Eyepiece design and system magnification determine field of view.

Andy

The size of the ocular lens can have a small influence on the field of view of an optical instrument. Its effect is not nearly so significant as is the distance of eye relief. Within practical limitations for an optical gunsight mounted on a sporting arm, the size of the ocular lens cannot be made large enough to have a significant effect on field of view. Likewise, the very small difference in the limitation on ocular lens size that is represented by the difference in a 25.4mm tube versus a 30mm tube also makes the size of the tube irrelavent to field of view.

The belief that eye relief has nothing to do with field of view can only arise from ignorance. Ignorance is excusable, but curable. Obstenance is not.

quote:

Originally posted by Stonecreek:
The size of the ocular lens can have a small influence on the field of view of an optical instrument. Its effect is not nearly so significant as is the distance of eye relief. Within practical limitations for an optical gunsight mounted on a sporting arm, the size of the ocular lens cannot be made large enough to have a significant effect on field of view. Likewise, the very small difference in the limitation on ocular lens size that is represented by the difference in a 25.4mm tube versus a 30mm tube also makes the size of the tube irrelavent to field of view.

The belief that eye relief has nothing to do with field of view can only arise from ignorance. Ignorance is excusable, but curable. Obstenance is not.

If a ~20% increase (likely larger, given similar dimensions for adjustment and mounting clearances) in diameter of lenses (and associated field stop) is deemed insignificant, I suppose that is a matter of opinion. Granted, some scopes use that space for additional adjustment range instead of wider field of view.

Ignorance alone does not lead one to personal attacks when the facts are not on one's side.

Andy

I regret that you interpret my comments as a personal attack.

Perhaps you simply misspoke and did not intend to actually state that "Field of View has NOTHING to do with eye relief!" If that is the case and you will correct that statement, then I will be proven wrong as you will have illustrated that obstenance is indeed curable.

By the way, are you implying that (all other things staying the same) a 20% increase in the area of the ocular lens will translate into a proportional increase in FOV? If not, then what increase in FOV can be expected, and how significant would it be?

The scope's exit pupil is your access to viewing through a scope. The eye pupil engages the exit pupil of the scope so you can see what is in the field of view of the scope. The exit pupil is not dependant on the size of the ocular lens, nor is field of view or eye relief. All are design features of the scope, but not on the size of the ocular lens. The ocular is only there to focus the reticle, and provide a place for the pupil of your eye to see through the exit pupil of the scope, which is like a tube of light, into which you place your eye pupil.
Field of veiw and eye relief are related, but have nothing to do with the size of the ocular lens. The ocular can be one or two inches in diameter, and the scope's exit pupil would remain the same, all other design features of the scope held constant.

Don

quote:

Originally posted by Stonecreek:
I regret that you interpret my comments as a personal attack.

How else do you intend someone to interpret being called incurably obstinate? However, if that was not your intention, then I accept your regrets.

quote:

Perhaps you simply misspoke and did not intend to actually state that "Field of View has NOTHING to do with eye relief!" If that is the case and you will correct that statement, then I will be proven wrong as you will have illustrated that obstenance is indeed curable.

Eye relief is not a factor in computing field of view of an optical system. One cannot compute field of view using eye relief without other factors that would allow one to compute it without using eye relief in the first place. That is pretty much the definition of "nothing" to me. Eye relief does place practical limits on physical design to implement a given field of view within other limitations such as the diameter(s) of eyepiece lenses.

You previously stated that you cannot tell whether a 2.5x scope has a wider field of view than a 3x scope, unless you know the eye relief of each scope. I repeat that knowing the eye relief does not allow one to know the field view, unless one is also aware of other factors that would allow one to know the field of view in the first place.

quote:

By the way, are you implying that (all other things staying the same) a 20% increase in the area of the ocular lens will translate into a proportional increase in FOV? If not, then what increase in FOV can be expected, and how significant would it be?

First of all, the lenses I believe we were referring to were the field lens(es) and/or erector lenses located in the tube of which we are debating the merits of a ~20% increase in diameter. The diameter of the other (rear) ocular lens(es) has only an indirect effect on field of view (other than in perhaps a limiting factor).

Given that the optics market is reasonably cost-competitive, manufacturers are not in the habit of providing expensive lenses that are larger (and more expensive) than required to illuminate the entire field of view. Therefore, it is a fairly safe assumption that if the manufacturer increases the size of the field and erector lenses (those housed in the straight portion of the tube), it is done so for the purpose of increasing the field of view, or more fully illuminating the existing field of view, or a mixture of both. The maximum increase in field of view would be in the same proportion as the increase in lens diameter; i.e. a 20% increase in lens diameter (all other things held equal) would afford a 20% increase in field of view.

Andy

quote:

Originally posted by DMB:
The scope's exit pupil is your access to viewing through a scope. The eye pupil engages the exit pupil of the scope so you can see what is in the field of view of the scope. The exit pupil is not dependant on the size of the ocular lens, nor is field of view or eye relief. All are design features of the scope, but not on the size of the ocular lens. The ocular is only there to focus the reticle, and provide a place for the pupil of your eye to see through the exit pupil of the scope, which is like a tube of light, into which you place your eye pupil.
Field of veiw and eye relief are related, but have nothing to do with the size of the ocular lens. The ocular can be one or two inches in diameter, and the scope's exit pupil would remain the same, all other design features of the scope held constant.

Don

I'm not sure what you are trying to say...

Exit pupil is the diameter of the bundle of light emitting from an afocal optical system (one that does not form a focus external to the optical system; your eye's lens forms the focus on the retina) Exit pupil is not directly related to field of view or eye relief.

Given that the apparent field of view (real fov X magnification) cannot be larger than the apparent angular diameter of the rear ocular lens (determined from the diameter and the eye relief), this places an upper limit on field of view for a given ocular diameter and eye relief. However, there are other factors which may dictate a larger rear ocular lens than otherwise necessary from a pure field of view aspect, such as distortion and control of abberations. Therefore one cannot simply take the ocular diameter and the eye relief of an arbitrary optical system, and compute the field of view.

Andy

quote:

Originally posted by BigJakeJ1s:
Eye relief is not a factor in computing field of view of an optical system.
Andy

As I had initially judged, incurable.

(Not a personal attack, simply an observation.)

Objective lens:
The objective (in a conventional systemic sense) gathers light, magnifies it, inverts and reverses the image and, if properly done, corrects that image to perform satisfactorily as a part of the overall system. There are other jobs the objective can perform.

Erecting system:
Most scopes use an erector lens system (some scope uses an erecting prism), to capture the rays from the objective, magnify and reverse the inversion and reversion of the image and correct the image further. If an erecting prism is used, there is typically little or no magnification that takes place. An erecting prism does, however, usually shorten the overall length of the system. There are other jobs an erector system can perform but they will not be mentioned at this time.

Reticle system:
Reticular-aiming points can be front or rear focal point oriented. They, historically, have been metallic, membranes, synthetic and/or natural wire (hair), and glass.
Glass is superior in that the optical system can be further corrected and enhanced by glass, if properly done. A three element sandwiched glass reticle, using corrective differentiated glass, optically coated (and in some cases with curved surfaces), helps correct the system far better than a single pane of glass (plano-plano). This is the most difficult and expensive reticle to build in a conventional scope system. U.S. Optics has a patent pending on this type. The other reticle materials mentioned above cannot possibly add to, or enhance the optical system under any circumstances. Please be clear in your mind about that.

Ocular system
Most ocular systems are designed to do the final correction to the entire optical system. This results in effect modifications of the performance characteristics happening at and behind the second focal plane, such as eye relief, exit pupil, field of view and object enhancement on the focal plane. There are, again, other jobs the ocular can perform.

I forget who wrote this....believe it was on a US optics site.........

woods

quote:

Originally posted by BigJakeJ1s:
Field of View has NOTHING to do with eye relief!Andy

quote:

Originally posted by BigJakeJ1s:

Given that the apparent field of view (real fov X magnification) cannot be larger than the apparent angular diameter of the rear ocular lens (determined from the diameter and the eye relief), this places an upper limit on field of view for a given ocular diameter and eye relief.
Andy

Andy, I don't know the optical equation to explain all this but what you are saying here completely contradicts itself. In one post you say it has "NOTHING" to do with it and in another you say it is determined by it and the diameter?????????????.......................DJ

quote:

Originally posted by djpaintles

Andy, I don't know the optical equation to explain all this but what you are saying here completely contradicts itself. In one post you say it has "NOTHING" to do with it and in another you say it is determined by it and the diameter?????????????.......................DJ

Re-read very carefully what I wrote. To paraphrase, X cannot be larger than Y, that is determined by Z. That is a far cry from saying X is determined by Z!

In engineering there is a difference between a limiting factor and a determining factor. A determining factor will always affect the output, whereas a limiting factor only does so under specific conditions. Eye relief is a limiting factor on field of view. Now if you insist, under specific conditions, that may be interpreted as not NOTHING.

In the interest of halting this pointless conversation, I will yield that point!

Now, on with other interesting topics!

Andy

quote:

Originally posted by BigJakeJ1s:

Now, on with other interesting topics!

Andy

Ok, How about that the "Limiting Factor" on the size of a rifle scopes Ocular isn't asthetics. It can only be so large without interfering with the bolt handle...........................................DJ