Home Forums Hunting & Shooting Hunting Optics 40mm vs 50mm

How many guys here use 50mm objective scopes in the field? I have seemed to prefer the 40mm objectives for the most part. Is there much benefit to the 50mm? I like my scopes mounted higher than most seem to on this site. I like to have medium height rings. I think the 50 would fit on this in most cases. Is it worth the extra money to go to a 50mm say in the Ziess Conquest?

Oakster,

I mounted a 50mm Bushnell on two of my rifles. One, the lighter of the two rifles is getting a 52mm glass because its lighter and better in low light.

The idea of a solid cheek weld does not apply to my shooting. I hold my rifles like I would a B B gun.

Biggest scope I have is a Zeiss with a 44mm objective. The only scope I can see me buying with a 50mm objective is a Conquest or VX3 megascope, like a 6.5-20x50.

3-9 models, no.

3.5-10 models, yes.

like a 1" ,42-44mm myself for brightness /sticking in a guncase etc. on a hunting rifle

My experience is that 50mm won't fit in some cases and you can't lean it against a tree. I sold mine and won't have another unless it's on a target rifle.

We do most of our hunting at night (hogs/coyotes etc) so nearly all of our scopes are 50mm.

When I was a child, I did childish things and embraced the notion that "bigger is better", including 50 mm scopes. When I became an adult, I put away childish things.

dawaba,

So, let me git thsi straight. YOu can see in low light with an adult 40mm scope better than you can with a childish 50mm scope?

40mm class scopes always get me past legal shooting light, so I have absolutely no need for anything bigger. For hogs and 'yotes at night we use a spotlight, so obviously no need there either.

You just can't mount that 50mm low enough.

I go for the smaller objectives.....40mm and under.

The higher you mount your scope, the flatter your trajectory will be. Just ask Ringman.

i sat in a deer stand this evening hoping some pigs would come to the feeder. No pigs but had 8 deer - all bucks - that i watched for over 2 hours and had to run off when i left.

i was in pretty thick cover but feeder was only 50 yards away. Moon is a little less than a half moon and was high in the sky after sunset

i had leica geovid 8x42 binos and a zeiss victory 3.5-10x42. Both got me to 50 minutes after sunset, which is when i got down.

The zeiss got noticably darker when i cranked it up to 10x but was fine on 6-8x (I guess i know how much my pupil dialates now).

In an open field with the half moon I'd probably still be sitting there.

A decade or so ago, I sat one evening on my back porch with 2 Leupold Vari-X IIs, a 3x9x40 and a 3x9x50. Neither was mounted on a rifle, so I taped them together and alternately glanced through them as the light faded into darkness. It was well past legal shooting light before MY EYES could grasp any difference, the laws of physics and light transmission notwithstanding. I suppose that a leopard hunt over bait in Zimbabwe MIGHT be an instance where the larger objective would be desirable, but even that could be subject to debate.

I abhore the current fad of choosing gigantic and heavy scopes to mount on a carrying rifle. The gun appears to be mounted on the scope, rather than vice-versa, and that just violates the Law of Aesthetics, which to my eye, almost always trumps the Law of Physics. If you own a 12 lb David Miller gun for Coues hunting, well, a big scope looks right at home, but not on the average shooting rig.

My next door neighbor, a good hunting buddy, remains a child, although he's 58 years old. ALL of his scopes--he owns around 10, I'm guessing--are 50-56 mm, and all of his rifles are ponderous things that look like a sniper or long-range outfit. Not one is a carrying gun. But he has bad knees, will need knee replacement soon, and hunts from the road nowadays. To him, a light rifle topped with a well-balanced, trim scope is childish. But we are still buddies, and I even carried his pack and 10-lb 7mm Mag rifle for him while he struggled up a Santa Rosa Island hill in 2009 to collect a fine muley buck. He was almost as proud of his deer as he was of his 56 mm Zeiss scope. For the record, I toted a 7Mag too, with a 4.5x14x40 Leupold. My neighbor owns this same Leupy too, but in the 50 mm persuasion, of course. So, to each his own....

I will continue to buy good 40 mm glass. The 50 mm stuff is just too bulky and awkward. Good 40 mm scopes will take me past the end of legal light. No need for more. I do like 42-44mm on varmint scopes because of the higher magnification, but no 50s for me.

YEP ! 42 seems to be my sweet spot and you can still mount them low.

What's the value of "low"?

My understanding of the way a scope works. An average human has a 4mm pupil during the day and about 7mm adjusted for dark. You take the objective divided by the magnification to get the exit pupil of the scope. Anything greater than 7mm in low light conditions or more than 4mm in the middle of the day is wasted.

3.5X10X40 scope with magnification at 10. 40/10=4 which is great for daytime. If you ajust the magnification to 5. 40/5=8 which is more than the average eye can accept.

If you had a 3X10X50 set at 10. 50/10=5 which is more than you need during the day and you will be able to set magnification to 7 instead of 5 to receive the same amount of light. Not a big enough difference to me to have to mount the scope higher and I don't like the looks of the 50.

The important point is doesn't matter how big the objective your eye can only take so much light and if you understand this concept you can adjust any size scope to the same brightness level by adjusting the magnification.

All that being said I go for the best glass I can afford and prefer a 42mm and don't care for any scopes over 14power. I currently have a new swarovski z3 3x10x42 on my M70 SS Featherweight .270 and at only 12 oz is easily the best scope I have ever owned.

I wouldn't say "wasted." A larger exit pupil makes it easier to get in position behind the scope; the eyebox is less critical. And I think that has value, especially if you have to get a shot off quick.

As stated earlier, a larger objective will let in (not "gather") more light but what happens to that light after that is a function of the quantity and quality of the lenses and their coating. A larger objective does not guarantee that you will have a brighter picture at the other end.