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

my Barska 6-24 x 60IR Tactical Swat mildot reticle scope mounted on my new Ruger 16.5 inch barreled 325WSM Frontier Rifle in Krypton SuperRings is just about perfect for hunting fiddler crabs in the near dark. I keep a 6 Volt lantern lashed to the top with camoflaged tape and the whole outfit is a short and easy to carry 12 pounds full up! I love the Barska 60X scope it really gathers the light, so much so that I have to wear sunglasses at night to protect against flash blindness when I take a shot with my rifle. The absolute coolest thing is that the scope is almost exactly as long as the rifle barrel!

I don't have many 50mm objectives!

On the elk hunt this year my *50-year-old huntin' bud complained that his 4.5-14x 50mm Leupold was disappointing in its ability to help him see elk moving around in a meadow before dawn - in fact it was no better than my 3.5-10x 40mm Leupold, which is more than enough scope but not a night-vision device.

I tried to tell him that it wasn't really necessary to buy that more expensive top-heavy 50mm version in extra-high rings, but he is a true "if it is bigger - it must be better" kind of guy.
So I just had to laugh about the whole incident!

*The scope�s EP corresponds to our pupils, which dilate to a maximum of 7mm in a young person, decline to about 5mm by age 50 and another millimeter each decade after that. If a scope�s EP exceeds the diameter of ours, the rim of extra light spills out onto our irises, wasted.

Other points aside, I am greatly encouraged by the fact that nobody here has given the fallacious argument that they want the huge objective because it gives a wider field of view. I got so tired of hearing that when I sold scopes that it nearly made me weep. This is clearly a (ahem) brighter crowd.

RockyRaab
One of the overlooked facts is that if you tap the objective of a 50 mm scope. it moves the cross hairs less than it does on a scope with adjustable parallax...

That's kind of a peaches and pomegranates thing, isn't it? What about a 50AO?

Well, it will move the crosshairs on a 50mm AO, but not as much, proportionately, due to the larger field of view...

Sorry... LOL

The trend migrated to the US from Europe...but in Europe they typically can hunt at night without the use of a light.

You haven't read the rest of this thread have you? Simply put this statement is false.

I actually had mine measured before surgury, I'm 47 and they were 7.2mm in low light..................................DJ

Well if you want to believe what Frisco states, by the time you reach 100 your pupils will disappear...............

We all just need to not take rough "rules of thumb" as the Gospel truth. Some people may never have pupils that dialate even all the way to 7mm -especially smokers, and others will of course defy the commonly held truth.

Best thing of course is to find out for yourself......................DJ

I hate it when I have been fed wrong information by some gun writer!
I stand corrected, I suppose.

I have many different objective sizes & magnifications depending on the rifle & application. A .308 Sako with a Mannlicher style stock with a 4X Weaver, a .376 Steyr, .35 Whelen, 50 cal. ML., & 30-06 all with 6X42's, a .280 with a 2 1/2-8X36, a .260 mountain rifle with a 2-7X33, .300 Win.Mag. & 7MMUM with a 50MM, & a host of others with 42/44MM. My DGR wears a 1 1/4-4X24. I have no problem with a 50MM especially for stand hunting or long shots. I prefer each type of scope for a particular application. I haven't even mentioned Ill. scopes I use for night hunting.

I'm in the same boat as dj. Prior to laser surgery my Doctor checked my pupil dilation, and found mine dilate to 8mm. I was 48 when I had the surgery done. I had to have prosthetic lenses implanted, replacing the natural ones, that are anti-glare before he would do the surgery. I can utilize an EP of 8mm.

Not everyones has. Unfortunately, you are correct to the extent that many have though - at least I would assume that is partially the reason why Burris no longer makes their fine Fullfield I 4X scope.

I am absolutely satisfied with a scope which hugs the rifle. Anything the sticks out farther has absolutely no advantage to me. Smaller, dimmer, but working beats bigger, clearer, and tweaked every time. It's right for me, though many people - most of who probably spend less time hunting than I do, seem to choose a different version of "right".

Yup, anything that sticks out all the time is liable to cause trouble.

As John Holmes could have told us ...

Rocky,that's funny!!!

I've done a research and a few things.

1.For most of us legal shooting hours are from 30 minutes before sunup to 30 minutes after sundown.
2.The average human eye pupil size at night is a little over 7mm.
3.To find the exit pupil size of a scope you divide the objective lens by the power setting on the scope.
4.No scope will transmit 100% of available light to the eye. The very best scopes will transmit 98% of available light to the eye. Most will transmit between 90-95%.

So the trick is to to match our pupil size at night, which for most is less than 8mm, to the exit pupil size of a scope, so we can make a shot in that first or last minute of the legal shooting hours.

With my 2-7x33's set at 4x the EP is 8.25mm, at 5x it is 6.6mm.
With my 3-9x40's set at 5x the EP is 8mm, at 6x it is 6.67mm.
With my 4-14x56 set at 7x the EP is 8mm, at 8x it is 7mm.

I guess these 50+mm lens are helpful to some hunters, particularly those that hunt over feeders and agi fields.

But I sure don't want one on my stalking rifles.

It is my understanding that the 50 PASSES more light through the scope than a 40 does. No scope can "gather" light.

Have I been mislead all these years?

Dew

Priceless...............