40mm vs 50mm objective

lead lobber

I am new to the scopes that cost more than rifles but want to get a leupold vx II 3X9 40mm. Is there a big advantage to a 50mm objective or is it hype. I have heard that the eye can only make use of the light from a 40mm and the 50mm is not used by the eye. I like the scope to be low on the rifle so would like to stay from the 50mm. I will be hunting deer.
Also is there a big diffrence between the VX II and the VX III the 3 is about $200 more. thanks



Edited by - lead lobber on 06/18/2002 15:04:19

Nighthawk

I will answer this question to the best of my ability. I think its a matter of opinion. But I own both type of optics and I cant really say the 50mm scope really gathers more light than the 40mm.To put it plainly If I were hunting with my 40mm scope Instead of a 50mm, at dusk or dawn, I could not blame the scope for not gathering enough light. And I have noticed that you seem to get a less distorted picture with a 40mm objective,than with the 50mm.

Rugster

bullelk

There are a few different ways of light gathering and brightness. The larger is going to give you more light, but about the only time you can tell the difference is at dawn and dusk.
Then don't quote me on the rest of this, I'm taking it from memory.
Their are formulas, such as the power divided into the objective diameter, I think. Exit pupil diameters, Lense coatings, all are factors to some degree.

The 40mm will be plenty good enough for deer hunting.

I may not be 100% right, but I'm close.

bullelk

"If All Else Fails, Read The Directions"

robsguns

All the above comments are correct in their own way, and then some. There is a formula, and it is like what has been stated. It all comes down to the size of the exit pupil and how much light the human eye can use, which is about 4mm worth. If you have a 50 mm objective and a 10 power scope the exit pupil is 5 mm, more than can be used by the eye. 40 mm objective with a 10 power is 4mm, understand?, right in the ball park of what the eye can use. Now as you go up in power the larger objective has a good use, to increase the exit pupil in correct proportion. I called Leupold and the man I spoke to actually talked me out of buying a 50mm, as he told me the above, in a nut shell. He also talked me out of buying the adjustable objective. The customer service at Leupold is very helpful in explaining this in detail, give them a call. 503-646-9171 or view their website for info. on the VX models. http://www.leupold.com/

SSgt Ryan E. Roberts, USMC

Edited by - robsguns on 06/18/2002 19:48:31

bullelk

Ryan,
Thanks for clarifying my post, I knew I was close, and I didn't want to give him any wrong information.

bullelk

bullhauler

The sarge is correct; but, let me shed a little more light on the subject for you. The light gathering ability of a scope also relies on tube diameter to transfer that light to your eye. According to the fine folks at leupold a 30mm tube will transfer a larger amount of useable light to your eye than a 1" tube. Although the eye only has use for a certain amount of light, the 1" tube restricts it to some extent. The main thing is to make sure to buy a quality scope(my rule is always pay for the scope at least what you pay for the rifle). Putting a cheap scope on a rifle is like putting white spoke rims and used tires on a cadilac. Make sure they use quality lenses and that the lenses are multi-coated in some fashion. Hope this helps.

welcome to America...now speak english or get the ****out

JustC

I will agree with a bullhauler's suggestion as well as robsguns. You would be well served to go and look at the scopes with 30mm main tubes and 40-44mm objective lenses. A 30mm tube with a 40mm objective gathers more light that a 1" tube with a 50mm lens. I have found that the tube diameter makes the biggest difference. I will not even try to explain why it makes better use of the light, if I knew exactly why, I would be a wealthy scope manufacturer. I just know it works.

Burris Black Diamond has 30mm, as do the Leupold Long range models.


A great rifle with a junk scope,....is junk.

hitman

My only argument for the 50mm is it looks pretty tough. That being the case, I got rid of one of mine after lugging over the hills all day. I went back to a smaller scope. I guess I'm not so tough. If you want to impress people when you take your gun out of the case go with the 50mm.

Hitman

Shootist3006

One other consideration; the bore of the 50 MM will be almost 1/2 an inch higher than a 30 MM. This will require that you hold your head at an awkward angle (or add a cheek piece to your stock) in order to sight through the scope. That extra height makes a lot of difference and it isn't good.

Quod principi placuit legis habet vigorem.Semper Fidelis

JustC

shootist3006 you are correct, but, if you get a 30mm tube with a 40mm objective, your scope is still closer to the gun than the 1" with a 50mm. My mark IV's sit right on top of the .900+ barrels that I use. They still clear the contour also.

A great rifle with a junk scope,....is junk.

lead lobber

Ok Thanks for the info. Its gonna be a 40 mm. It looks like the 30mm tubes are out of my price range. Now My current scope is a tasco 3-9 that cost $29. How much more light do you think the leupold scope will bring in? Is it worth the extra 200 to buy the V III, or should i save 200 and get the V II? I shoot deer at 20 to 100 yrs but want to be able to shoot 200-300 yrs if I get the chance

HUNTER30

I have a VX-II on my muzzleloader.I think they are a very good scope & i would by another one. Hunter

cpermd

Listen up LL
The kids who have answered have tried to be helpful.
They add to their post count is all they do.
Rugster is the worst,he will post about anything.
The 50 mm will give you a 25% greater exit pupil in a good scope.
It will bring in 60% more image and light.
A 30 mm tube will transport 40% more image.
A 50 mm obj only adds 10 mm which is 5 mm up and down.
That is 0.12" higher which is not very noticeable
cpermd