How big an Objective Lens do you need?

B

BrianBM

New member
Never mind varmints at long range, I'm thinking of deer, on that .280 I'm slowly stalking. Maybe a pig. If you want to make sure you can make a shot very early or very late, on an overcast day when the light's low (and very blue), do you want a large objective? Never mind magnification, this is a different question. I suspect that low light level, rather then great magnification, is the best reason for an objective of 40mm and up. BUT, I've never hunted. So what do you think? What properties do you want, in the scope on the rifle in your hand, when a large buck appears in your binoculars at 200 yards in the last minute of legal hunting hours on an overcast day?
 
Depends of the mfg, lenses and coatings. My Leupold 3x9x40mm Vari-X II with the "multicoated" lenses seems to transmit just a little more light at near-dark:30 than my 50mm Tasco world class.But the difference isn't all that much and I'm not sure the cheaper Leupolds with only "fully" coated lenses would perform as well.

I hunt with and have lots of confidence in both of the above scopes. I own other scopes by Tasco, Simmons and Bushnell BUT they aren't nearly as good as my Leuold and the Tasco World Class.
 
That seems reasonable - no one has a bad word about Leopold quality. There's a VX-III in the lineup, 2.5 - 7 I think, with a 36 mm lens; I might go that high, in price. Light transmission at low levels is probably too close to 40mm to matter, just a smidge up or down. I wish I could find a user's comment on any of the luxe Leopold glass, the LPS or (more interesting) VX-L series with that interesting cutout; but those are ....ahhhh ..... pricy. The VX-L at 3.5 - 10x is more magnification then I can imagine needing, but being able to put a 50mm lens that close to a barrel has GOT to be useful. So far, Google finds nothing about that lens save retailers' ads, no reviews of usefulness away from the range.

Anybody here do any shooting through LPS or VX-L scopes? I'm curious as heck. And any further comments on the optimal front-lens size for deer in very, very bad light are still very welcome. :)
 
First, I have no answer to your real question, but have one of my own to throw in...

Wouldn't a variable-power scope act like a telephoto zoom lens, reducing the effective aperture as magnification is increased, as well as being slower overall than a fixed-power scope with the same sized objective?

In other words, is a variable scope a handicap in low-light situations?

--Shannon
 
I have a VX-III with a 50mm on it. In hindsight, I should have gotten a 40mm. The 50 really brings in the light, but sits higher than the 40 would.
 
My 22-250's 4.5-14X has a 40mm objective, and I have fired it after sundown at coyotes. It was plenty bright. My 7X57 has a 2.5-7X Leupold VX-I on it, and the objective is 38mm, I believe. I have fired at game 1/2 hour after sundown and thought it was plenty bright. When I took the scope away from my eye and saw how dark it really was, it amazed me! So I think a 40mm objective is probably plenty. The higher the magnification, the smaller the exit pupil with a given objective size. So at higher powers, you might need a bit more.
 
tube_ee, I think you're correct. BUT, who is to say that the deer that pops up in the blue ligh minute is going to do so at a particular range? A fixed 4x40, say, would be GREAT if it does so at 150 yards across a cornfield. OTOH if the two of you are looking at each other at 25 yards, if you're hunting a patch where ranges are short, it might be hard to find the deer in a 4x. You do want to be able to set up the scope for the range at which a deer is most likely ... I think. (Zero experience, 100% speculation.)

You've made an argument in favor of a modest range of magnifications ... and a large objective. I suspect that a 2x-5x with a large objective would be ideal for low light deer out to 300 yards, but AFAIK there is none.

Following the threads of adulation on the K-31, since those rifles are apparently accurate, and generally comparable to the .308, it occurs to me that it might be interesting to price out a VX-L on one of those, rather then purchase a .280 first and see what's left over for a sight. Still gotta leave money for reloading gear. I'm off to visit the optics zone, since he posts here and everyone speaks well of him.
 
Oh, yeah - John in Jax, the VX-II is my optical baseline. Definitely spend that much, might be willing to spend more. I'm educating myself all at once, on rifles, sights, and reloading.
 
Just came back from wandering around the optics zone, looking at rifle scopes.
Yeep. Some of that stuff, the US Optics and Schmidt & Bender ... that can get expensive, can't it?
 
Honestly, when I went to look at scopes, I was in a low light condition in Gander Mountain and could not see a difference between the expensive Leupolds and the Nikons. In fact, it seemed that the Nikon was a little easier to find the eye relief, but as for light, I thought they looked equally light, maybe even more so in the Nikon.

I still have yet to see more than buying a name with Leupold though, so I may be biast.
 
:D theres a thing about light transmission and how much your eyes can actually use, the rest is wasted. the human eye can only take in 7mm of light at the most, usually 5 or 6mm. knowing that, you can divide the objective lense size by magnafication level
ill give an example say i have a 50mm obj. lens and a 3x9 scope. i set it on 6. divide 6 into 50, answer is about 8.5 maybe, dont have a calculator on hand, but this shows that if youre eye takes in only a max of 7mm then the rest of that is not used and not needed. set it on 8 and the number would be6.3 or something which is still alot more than most eyes can take. so if you use a 3x9 50mm scope, the 50mm bell only comes into play on the highest setting.
my point is, you need no more than 42 on a 3x9, 40 is fine
2x7, no more than 36
only time a 50 would really help would be 4.5x14 or bigger but a 44mm would be adequate for a 4x12 and for 4.5x14 on most people.
this is peobably confusing but its true. trust me. scopes dont gather light, they only transmit what light is there. thats where the bigger bell comes into play, but if youre eye cant use it, you dont need it. unless you only use your scope on the highest power.
 
VA, I do understand .... interesting stuff. You post at ungodly hours. Make a good surfcaster, no doubt about it.
 
my thoughts, after shooting dozens of deer in failing light---3-9 or 2-7x40, quality scope like leupold, nikon, redfield etc. is all you'll ever need, just be sure to turn the scope down to its lowest setting for the last few minutes of light, as this will allow better low-light vision than even your naked eye (at least for me anyways). one more thought, i've never taken binoculars hunting--if you've got good optics on your rifle, why bother? plus if the deer is moving in dense cover you may not have time to fool with binocs. and get a shot off
 
for shooting legal hours around here (1/2 hour before and after sunrise/set) a 32 will work fine, but everyone still gets the 40's. oh, and i like the nikon monarchs for the money.
 
I took my vx-III with a 50mm objective down to south Texas for hogs a few february's ago. We were hunting at night under the light of a full moon with some scattered clouds. Hunting over feeders at about 100 yards. I shot a real nice boar and I was the only one out of six that could even find the feeder through a riflescope.

Sold me on the light gathering capabilities of large objective lenses.

Although this is an extreme condition, we get some hot weather during deer season and the best chance to shoot something is very early or very late. Its still pretty dark 1/2 hour before sunrise.
 
Quackfiend, binoculars would be easier to use for long periods, and would reduce the chance of doing something really, really dumb. I also think suitable binoculars afford the scanning user much better vision, especially at distance, then any monocular lens system could ever do, including better penetration of shadow.

kingudaroad, that's exactly the sort of situation I have in mind .... I know it'd make the collectors beserk to see a K-31 drilled & tapped to accomodate a Warne base and a high-end scope. Still, the price of a K-31 makes makes more money available for good glass. The latent accuracy of the rifle makes a 250 yard bang/flop reasonable for a thoughtful shooter, even a first-timer. For reasons discussed elsewhere, I'm going to be sitting in ambush, not stalking, and I might need to be some distance off from the clearing or whatever that I am surveying.

If I get a brief glimpse of a deer, as Quackfiend notes is certainly possible, I'm not going to take a shot. An ethical beginner should shoot ... thoughtfully.
Like someone said (I wish i could remember where I read this) "Slow is smooth, smooth is fast."
 
kingudaroad

i can see all night on a clear full moon with my 40mm up to about 10x. if you have a 3x9, the 40 will do the same as the 50.
 
All you collectors can rest more easily. I've been looking over the general enthusiasm for Darrell's K-31 mounts. Sounds good. Be at ease. :)
 
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