Home Forums Hunting & Shooting Ask The Gunwriters Why has everyone gone ape over larger, i.e. 50mm, objective lens on scopes?

When I was in collage 35+ years ago, I was taught that the eye could not use the light from an objective lens larger than a 40mm.
As I have grown older I have found that I can not see any better with a 40mm than I can with a 33mm. So I have moved to the smaller scopes while everyone else seems to be moving to the larger objective lens.
So, why has everyone gone ape over large, i.e. 50mm, objective lens on scopes?

I guess because some people think the Hubblescopes look cool, or will provide them some unspecifiable advantage.

I'm with you...I've gone almost totally to 4x33 and 6x36 scopes.

Dennis

I dunno nuthin' about the how's or why's, but the diff between a Loopy 3.5x10x50mm and a 3.5x10x40mm (or whatever it is) was easily apparant in low light to my eye.

It's the American "Bigger Must Be Better" mentality... turn brain off, follow other lemmings off cliff.

My two big game scopes average out 40mm....grin


The little Leupolds are pretty sweet though.

This Fud thinks they probably look cooler to the buyer, thus the attraction to the so inclined.

I like Leup 2x7s and 2.5x8s.


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...If a hunter is going to poach after shooting hours the 50mm and larger objectives do gather more light in those low light conditions. For legal hours hunting I see no real advantage to the large objectives, on BIG GAME scopes. I use 2-7X33,2.5-8X36, and a 4X30 on my favorite big game rifles, and a 1.5-6X20 on a dangerous game rifle. I hunt till dark, and have no complaints about thier performance even with 67 year old eyes.

....The varmint guys using 12, 14, 16, and sometimes 18X or greater magnifications could benefit from the larger objectives.

Brad, I must march to the beat of a different drumer. I'm not following any lemmings off a cliff.

Ya'll go ahead and use the small diameter objectives,no problem,but don't knock those of us that like larger 1's.I have 7-5.5x16x44s,2-2.5x16x50s and 5-3x12x56s.I just like them better for my eyes.

That "gathering of light" term is funny.

What good is more light if your I can not use it?

The 40mm limit you mentioned earlier isn't absolute. The size of the exit pupil depends on the magnification as well, and whether a given person can use it depends on that person's eyes. If your pupils don't dilate to more than 4mm then for 10x a 40mm scope will do all you need. If your pupils will accomodate 5.6mm then a big 2.5-10x56 may allow you to see better. It will be bigger, higher and heavier and you may not value the increased brightness enough to accomodate the tradeoff.

It's all about what does it for you. I generally prefer smaller scopes, but I own a couple of biggies too.

The oddest looking rifle I ever bought was used every little Marlin 336 SS with a 3.5x10x50mm Simmons Aztec Scope with see-thru mounts.

I traded the scope and mounts to my old smith for an action and trigger job and he thru in at the end an old Millet sight.

last year I ran into a guy that huge see thru mounts on a Ruger All-Weather. When asked why it was to accommodate the 56MM scope he had. IMO Ruger makes a nice factory ring set........why nobody would use them is beyond me!

I have never seen any difference in a 33MM over a 50MM obj. But then my name doesn't begin with E !!!

Cuz I like em, You got a problem with that?

No, I don't have a problem with it.
I just want to know if there is a logical reason why you and others like them?
IMO they mess up the handling and balance of the the rifle and are a lot heavier.

It's not funny to astronomers who happen to know a thing or two about telescopes and, of course, a rifle scope is a type of telescope. A larger objective lens will collect ("gather") more photons (light) than a smaller objective lens.



"The ability of a telescope to collect a lot more light than the human eye, its light-gathering power, is probably its most important feature. The telescope acts as a ``light bucket'', collecting all of the photons that come down on it from a far away object. Just as a bigger bucket catches more rain water, a bigger objective collects more light in a given time interval. This makes faint images brighter. This is why the pupils of your eyes enlarge at night so that more light reaches the retinas."
http://www.astronomynotes.com/telescop/s6.htm
http://users.zoominternet.net/~matto/M.C.A.S/powers%20of%20a%20telescope.htm#Powers%20of%20a%20Telescope


-Bob F.

As I have gotten older my eyes do not adjust as fast as the light fails in the afternoon. We can deer hunt in Arkansas until thirty minutes after sundown and the 50 mm objectives help me see better in low light in the afternoon. It does not help as much in the morning low light when the light is increasing instead of decreasing. If it does not work for you, you don't have to use it, but don't try to tell me that it doesn't help me. miles

I should have put :)'s......


Actually there are good reasons to use a larger objective scope if you hunt in marginal light. I'm 47yrs old and actually had the amount my pupils dialate measured in low light (not complete darkness and without dialation drops) at 7.2mm. So I for one go against the commonly held belief that noone over 40 can't use more than a 5mm exit pupil YMMV. If you smoked or had other conditions you might very well not be able to fully use even a 4mm exit pupil. The point is that for some people a larger exit pupil can make a real difference but maybe not for you personally.

The second point is that not all 50mm obj. scopes are heavy, some are a lot lighter than you think. A Swaro 4-12x50 1" tube is actually over 2 ounces LIGHTER than a Bushnell Elite 4200 2.5-10x40. A 30mm! tube 2.5-12x50 Swaro PH is less than an ounce heavier than the Bushnell even with a 30mm tube vs a 1" tube. Some of the 50mm and larger obj scopes are quite a bit heavier but not all. You really need to check the weight of individual scopes before making blanket assumptions.

I've got Swaro 4-12x50 scopes on 3 or 4 different rifles in LOW rings. They aren't necessarily as high mounted as you think either!

So if you can have a 50mm obj scope that you can see better with, that weighs the same or less as a lot of 40mm obj scopes and you can mount it in low rings to maintain a good cheek weld, why aren't MORE people using 50mm scopes? (in the Swaro 4-12x50mm case it's because they ain't cheap!) .................................................DJ

I know for a fact that optically the lunker Zeiss 3.5-10x44 spanks my very functional 6x36 Leupold. Especially towards dusk.
It is just brighter and clearer to my eye. No arguement needed.

Both are on rifles that have specific purposes.

Use whatever works best for you.