~40mm objectives Vs ~50mm objectives (500 yards and in)?

[jrock]

For me it is based on the FOV at the low end. I like at least 22 feet at the low end for a big game hunting rifle to cover the close range shots. Needs to be 6x50 or 4x40 to achieve this. I like more FOV so I'd chose 50 over 40 unless weight is a factor or features trump it. With good glass, and a medium to low power setting, 40mm will gather plenty of light for those morning or evening shots.

 

[Hand Skills]

I don't think optics work that way.

For example the Leupold VX5HD 3-15x44 and 3-15x56 have the same FOV.

 

[Backcountry sports]

I have read all about these scope sizes and debates and just wanted to see what the main consensus is here for medium range shooting (500 yards and in). All else being equal, the 50mm will gather more light, will typically be heavier and will typically keep the scope higher above the bore which means you might need a cheek rest added to your rifle. So do most people here hunt 40mm scopes or 50mm? Ive only ever used 40 and 42mm scopes. Thanks!

 

[jrock]

I don't think optics work that way.

For example the Leupold VX5HD 3-15x44 and 3-15x56 have the same FOV.

That rule was more like a guide line That is why I put a FOV number to go with. Just personal preference and by no means common to everyone.

 

[Backcountry sports]

50mm is the way to go

 

[J E Custom]

I have read all about these scope sizes and debates and just wanted to see what the main consensus is here for medium range shooting (500 yards and in). All else being equal, the 50mm will gather more light, will typically be heavier and will typically keep the scope higher above the bore which means you might need a cheek rest added to your rifle. So do most people here hunt 40mm scopes or 50mm? Ive only ever used 40 and 42mm scopes. Thanks!

The real reason to go to a 50 or 55mm objective is its light gathering ability. If you hunt in the dark woods, or in poor light they can be an advantage. they can be a disadvantage in other ways like you described. I prefer the 50+ mm objective as long as it is in a 30 mm tube. The 30 mm tube allows for bigger glass inside and more MOA adjustments in the Turrets. also the 30 mm tube scopes can be shorter in length than high powered 40 mm scopes.

On many of my personal rifles I still have 40 and 44 mm Objective lens for many of the reasons you mentioned, But for the low light conditions I prefer the 50 + objective lens for many reasons. I also like them because of there ability to gather more light in the lower power range for running shots.

As I get older, the better the light the better the shot, so I am slowly changing to the larger objectives.

J E CUSTOM

 

[VTbluegrass]

Depends on the magnification and if you are going to take that 500 yard shot in the last 2 minutes of legal light on a cloudy day. Also depends on the scope. I can not for the life of me distinguish any difference between 40mm and 50mm in the amount of light getting through a VX3 at 14 power. So I go with the lighter scope. Nothing of mine has higher magnification, but it would stand to reason based on the physics of scopes that higher the magnification the more it matters.
You will probably get more light transmission buying a higher end option of any objective size than you would by spending more on a large objective lens.

Also when it comes to taking an animal in low light I have trouble with losing the reticle especially when hunting in the woods or against dark back drops. So I may give up some potential light transmission for a lighted reticle.

 

[jrock]

I have a 50mm Zeiss HD5 and its basically night vision, even on 25 power.

 

[Orange Dust]

Y

The real reason to go to a 50 or 55mm objective is its light gathering ability. If you hunt in the dark woods, or in poor light they can be an advantage. they can be a disadvantage in other ways like you described. I prefer the 50+ mm objective as long as it is in a 30 mm tube. The 30 mm tube allows for bigger glass inside and more MOA adjustments in the Turrets. also the 30 mm tube scopes can be shorter in length than high powered 40 mm scopes.

On many of my personal rifles I still have 40 and 44 mm Objective lens for many of the reasons you mentioned, But for the low light conditions I prefer the 50 + objective lens foe many reasons. I also like them because of there ability to gather more light in the lower power range for running shots.

As I get older, the better the light the better the shot, so I am slowly changing to the larger objectives.

J E CUSTOM

YES, Old folks scopes are more expensive too. Why are we constantly penalized?????

 

[J E Custom]

PS;
There is an distinct advantage When hunting at night using a green aluminator and the 50 MM + scopes.

With the 50+ mm scopes, they are very good under these conditions, especially at lower power.

J E CUSTOM

 

[Rich Coyle]

The high end scopes of 16x or more with large objectives and tubes are absolutely superb in low light. They are heavier, but absolutely superb. Don't ever look through a $3k scope at sundown and you will remain happy.

Unless it's a z6.

 

[jebel]

If you are comfortable with 14x magnification max for the distances you are shooting, I don't think you need any larger than 40-42mm objective lens diameter. In daylight, you only need the larger objective when using higher magnifications (say, 20x+).

The more relevant question is when light is low at first light and nightfall. In these situations, I agree with these comments.

The column of light (exit pupil) that reaches your eye should be 7mm or more. Its easy to calculate by dividing the objective lens diameter by the magnification. Example: A scope with a 50mm objective lens that is set on 14x will have an exit pupil of only 3.6mm, far smaller than you would want in marginal light. But .... if you turn the magnification down to about 7x then you will achieve a 7mm exit pupil which provides the maximum light column usable by most eyes.

Now consider a scope with a 42mm objective lens. If you want to achieve the same 7mm light column you can use a magnification of 6x. Is the difference between 6x and 7x make enough difference for you to choose a 50mm scope? Something to consider.

Large objective lens just let you use slightly more magnification than smaller objective lens do.

The above assumes that the same quality glass is used.

The relative difference between a 40mm objective and 50mm objective in low light is about 7x magnification vs. 8x magnification to maintain a clear picture (with enough light). If that 1x difference in magnification is inconsequential to shots you would take in low light, go with the 40mm. If that 1x extra magnification is profoundly important (enough to outweigh added weight, height, and cost), go with the 50mm objective. People will decide differently, but that's the basic issue to consider.

 

[Calhntr]

Out to 500yds every 40 and 42mm I run, leupolds, zeiss, Burris, vortex, meopta, Swarovski, no problem, dont need or gain a heck of alot out to 500 with anything bigger.

 

[Orange Dust]

My k525i went down at 5:40 this afternoon looking at a feeder 10' in the woods, 200yds away. I was in a field. By going down i mean the point i would not have been able to count points on a buck at the feeder. This is on 15x. It never did go down in the field. Im in arkansas. My leica 2800 went down 10 to 15 min earlier. By going down i mean you couldnt see well enough to range an object. Sunset was 5:00 on the dot..

 

[Rich Coyle]

Ten ounces too heavy!