30mm or 1"
12-18-2009, 06:09 PM
#11
Boone & Crockett
Join Date: Feb 2003
Posts: 10,679
There are two types of 30mm tubed scopes.
Those that have larger lenses than 1" tubes and therefore allow more light to pass through them and those that have equal sized lenses but allow a greater range of adjustment.
Typically tactical 30mm scopes will have 1" glass internally to allow for a greater range of adjustment for windage and elevation corrections. This is how Leupold scopes are manufactured.
Typically European (Swarovski, Meopta, Zeiss) hunting scopes will have larger internal lenses to allow more light to be transmitted through the scope.
The size of the exit pupil (determined by dividing the objective lens by magnification) simply corresponds to the diameter of the ring of light when it reaches your eye. It is true that your eye will only dilate to a certain diameter. If the exit pupil of the scope is larger than your eyes pupil then the light outside your pupil is wasted light. However if the internal lenses through out the scope are larger they will allow the exit pupil to be brighter.
A very simplistic way to look at this is to take two equal rooms that are the same in every way except the size of the window in each. One room has a 1'X1' window and the other room has a 2'X2' window. Which window will transmit more light into the room?
The other benefit to a 30mm tube is that they are stronger than a 1' tube of equal length.
Leupold isn't going to tell you the advantages of why you should buy some other companies scope because as BC explained Leupold does not use 30mm glass in any of their scopes. They are simply giving you the advantages of Leupold 30mm scopes compared to Leupold 1" scopes and not Swarovski 30mm scopes. However, they do tell you that light transmission "is a function of optical design and not tube diameter". Optical design includes lens diameter.
Those that have larger lenses than 1" tubes and therefore allow more light to pass through them and those that have equal sized lenses but allow a greater range of adjustment.
Typically tactical 30mm scopes will have 1" glass internally to allow for a greater range of adjustment for windage and elevation corrections. This is how Leupold scopes are manufactured.
Typically European (Swarovski, Meopta, Zeiss) hunting scopes will have larger internal lenses to allow more light to be transmitted through the scope.
The size of the exit pupil (determined by dividing the objective lens by magnification) simply corresponds to the diameter of the ring of light when it reaches your eye. It is true that your eye will only dilate to a certain diameter. If the exit pupil of the scope is larger than your eyes pupil then the light outside your pupil is wasted light. However if the internal lenses through out the scope are larger they will allow the exit pupil to be brighter.
A very simplistic way to look at this is to take two equal rooms that are the same in every way except the size of the window in each. One room has a 1'X1' window and the other room has a 2'X2' window. Which window will transmit more light into the room?
The other benefit to a 30mm tube is that they are stronger than a 1' tube of equal length.
Bigcountry, Sorry, but I will rely on the optical experts from Leupold. This is directly from their website:
The Leupold Answer Guide
Advantages of a 30mm Maintube
Does a 30mm main tube give you more light? The principal advantages of the 30mm tube are added strength and increased adjustment range for windage and elevation. For example, the M8-12X (1" main tube) has a total elevation adjustment of 51 minutes. The Mark-4 M1-10X (30mm main tube) has 90 minutes. The percentage of light passing through a scope is a function of lens coating and optical design, and has nothing to do with tube diameter.
I assume that Leupold does have some valid expertise in scope design.
The Leupold Answer Guide
Advantages of a 30mm Maintube
Does a 30mm main tube give you more light? The principal advantages of the 30mm tube are added strength and increased adjustment range for windage and elevation. For example, the M8-12X (1" main tube) has a total elevation adjustment of 51 minutes. The Mark-4 M1-10X (30mm main tube) has 90 minutes. The percentage of light passing through a scope is a function of lens coating and optical design, and has nothing to do with tube diameter.
I assume that Leupold does have some valid expertise in scope design.
Last edited by bigbulls; 12-18-2009 at 06:20 PM.
12-21-2009, 04:46 AM
#13
Fork Horn
Join Date: May 2009
Location: South Dakota
Posts: 149
any opinions on the Mark 4 4.5 x14? I am also looking at putting one on my new 270wsm. I would rather get the 1" tube, but can get the mark 4 for a lot cheaper thru special programs for military.
I dont know if the extended turrents will cause problems with carrying and packing.
I dont know if the extended turrents will cause problems with carrying and packing.
12-21-2009, 06:21 AM
#14
Guest
Posts: n/a
any opinions on the Mark 4 4.5 x14? I am also looking at putting one on my new 270wsm. I would rather get the 1" tube, but can get the mark 4 for a lot cheaper thru special programs for military.
I dont know if the extended turrents will cause problems with carrying and packing.
I dont know if the extended turrents will cause problems with carrying and packing.
I don't currently have one, but have fondled a few. Its close to as good as it gets. I am sure others will tout the kraut glass. But I will be thrilled to get one.
