12 replies [Last post]
Offline
Moderator
Joined: 01/27/2002
Posts: 7916
Big Game Rifle Selection... (Feature Article)

July 2004 Feature Article:

Big Game Rifle Selection from a Female Perspective

Please use this area to post comments or questions about this feature article.

Offline
Location: lehigh acres FL
Joined: 10/31/2003
Posts: 15
Big Game Rifle Selection... (Feature Article)

A 3-9X40 for open field's, & a 2-7X33 for light gathering ability in thick wood's or at dawn & dusk ?????

Offline
Location: lehigh acres FL
Joined: 10/31/2003
Posts: 15
Big Game Rifle Selection... (Feature Article)

A 3-9X40 for open field's, & a 2-7X33 for light gathering ability in thick wood's or at dawn & dusk ?????

Quicksilver's picture
Offline
Location: Colorado
Joined: 05/03/2003
Posts: 239
Big Game Rifle Selection... (Feature Article)

Flint, Did the article stutter?

The Leopold VX-II 2-7x33mm scope was designed to be a mid-range scope, ie "thick woods", and with the Multicoat 4 lens, as stated by Leopold, "Unparalleled light transmission in all light conditions.."

Basically, enhanced image clarity in all light levels, "Dusk or Dawn"....

Source: ?????

Offline
Location: lehigh acres FL
Joined: 10/31/2003
Posts: 15
Big Game Rifle Selection... (Feature Article)

Quick, the VX-II 3-9X40 also has multicoat 4 lens.
My point being the objective dia.. Personally,I would rather have a larger objective dia. in low light condition's (such as in thick wood's) for better light gathering capabilities than a small objective.
Personal opinion only, to each there own, thank's for your input.

Quicksilver's picture
Offline
Location: Colorado
Joined: 05/03/2003
Posts: 239
Big Game Rifle Selection... (Feature Article)

I guess it's safe to say, "It's all in preference..."

VX-II 3-9x40mm compared to the VX-II 2-7x33mm is a 1.4 inch longer than the VX-II 2-7x33mm, weighs about 2 oz. more, and comes with a little heavier price tag....

The actual Objective Diameter of the VX-II 3-9x40mm, is only, .2 inches or basically 1/5 of an inch larger than it's less expensive predecessor.

In General the VX-II 3-9x40mm is just a bulkier and longer scope than the slimmed down VX-II 2-7x33mm. If an individual was seeking a little extra light and that would justify the higher price, length and weight, I guess the VX-II 3-9x40mm might be a better choice. But, once again, "It's all in preference...."

Offline
Location: Colorado
Joined: 02/27/2003
Posts: 394
Big Game Rifle Selection... (Feature Article)

Well, if you do the math you find that at maximum magnification the 2-7x33 has a larger exit pupil than the 3-9x40, meaning that it should pass more light. Of course, if you turn the 3-9x40 down to 7 power--which is more of an apples to apples comparison--then it has a larger exit pupil and should pass more light. So, the question is, are you comparing them at equal magnifications or at each one's maximum magnification?

Personally, I would just get a fixed 4x scope since I've never found greater magnification than that to be very useful.

Quicksilver's picture
Offline
Location: Colorado
Joined: 05/03/2003
Posts: 239
Big Game Rifle Selection... (Feature Article)

Donmillion, for simplicity, it's safe to assume that a VX-II 40mm objective compared to a VX-II 33 mm objective based on size alone, the VX-II 40mm will have a greater light gathering ability.

The actual beam of light that reaches the eye, determined by "Exit Pupil", should be calculated by comparing each scope using the same magnification. "Apples to Apples..."

Just for information: Donmillion is correct...
Exit Pupil calculated using max magnification:

VX-II 2-7x33mm= 33mm / 7mag = 4.71 mm Exit Pupil
VX-II 3-9x40mm= 40mm/ 9mag = 4.44 mm Exit Pupil

Simple, at max magnification, the VX-II 2-7x33mm will actually pass a larger beam of light.

But, when comparing the same two scopes using the same magnification:

VX-II 2-7x33mm= 33mm/ 4mag = 8.25mm Exit Pupil
VX-II 3-9x40mm= 40mm/ 4mag = 10mm Exit Pupil

The VX-II 3-9x40mm passes a larger beam of light, as expected.

So, basically, a 7mm increase in diameter of an objective lens from 33mm to 40mm, increases the exit pupil size, along with the size of the light beam, by 1mm. So, the size of the objective lens is directly related to exit pupil size but the exit pupil size is not directly related to the light itself.

A better approach to analyzing the "light gathering ability" is to look at brightness which is determined by the quality of the lens, objective diameter, lens coating, and the overall scope resolution....

Ideally, the exit pupil is nothing more than a variable which dictates the size of the light beam that reaches the eye and has nothing to do with brightness or resolution which are the key factors during dawn & dusk light conditions.

Offline
Location: Wisconsin
Joined: 12/08/2003
Posts: 134
Big Game Rifle Selection... (Feature Article)

I don't know where everyone hunts, but where I do, there isn't a scope made that extends legal shooting hours. I can see perfectly well through any of my scopes when legal shooting begins and ends, although some are brighter than others. So for me, weight, size, and how it affects the balance of the rifle are all far more important.

Offline
Moderator
Location: Nova Scotia
Joined: 08/17/2002
Posts: 1762
Big Game Rifle Selection... (Feature Article)

I agree mister venison. I purchase a scope for its reliability, weight, and eye relief and after hours brightness has never been a deciding factor. I have always used Leupold scopes on my rifles and have never been disappointed or let down. I want to try the Bushnell elite series but am too chicken to switch something that has performed flawlessly.

Quicksilver's picture
Offline
Location: Colorado
Joined: 05/03/2003
Posts: 239
Big Game Rifle Selection... (Feature Article)

How useful is a scope, which may be perfectly balanced, light as a feather, and can be held at a comfortable distance from the eye, if, the image isn't bright, clear, and crisp?

But then again, what good is it to have the "Hubble Telescope" mounted to your 30.06, if it's to heavy to carry, and not well balanced?

As far as the dawn & dusk scenario goes, when used in the context of scopes, it is merely a test which is used to scale the quality of the objective lens glass, lens coating, prisim, and overall resolution by determining if the image has bright colors opposite to being washed out, clear as opposed to being dark, and crisp verse being blurry.

Not to be confused with testing a scope for "Poaching Ability"....

Related Forum Threads You Might Like

ThreadThread StarterRepliesLast Updated
Rifle selectionnewbie1207/05/2003 07:58 am
Rifle selectionnewbie1906/14/2004 12:09 pm
New Bow and Rifle for 2011Perry106/16/2011 11:19 am
New to hunting looking for advise on Rifle selectionNewbienCal4404/04/2013 17:14 pm
what caliber for my daughter?unbridled1503/06/2006 22:40 pm