Hello everyone, would like to hear what you all think of the low magnification scopes made by Zeiss, Leupold, Swaro, etc. with smaller objectives (20 and 24 mm). Any issues with light gathering out of these smaller objectives? Intended use would be plains game and buffalo.
Yes and No.
The very worst scope I’ve ever owned for low-light work is the Leupold 1.5-4.5x20mm. I know its like $400, but it is absolutely awful. I relegated it from rifle use down to a Ravin crossbow and even at 35 yards its such garbage at dusk and dawn for white tails.
Now the very best scope I’ve ever owned, and I’ve owned a LOT of them and used them for probably 30-50 big game animals is the Swarovski Z6 1-6x24mm EE. I’ve used it at 9pm in Northern Canada, I’ve used it to clearly view a hung bait in Africa at all hours. It’s so good for about every application I’ve ever had need to own an optic. Shots at 5 yards in the jess? Sure. A shot on a bushbuck at 345 yards? I did it. I’ve put them on 375HHs, 318WRs, 470s, 7x57s, 340 weatherbys, crossbows, 7x64s, 7x65rs, 404s, 300HHs, drillings, 458s, etc.
Here’s the math when you have a scope with incredible clarity and light gathering like the swaro. The human pupil in a male over age 35 can open to roughly a maximum of ~6.5mm in total darkness. So that’s the maximum light absorption you can bring in. A 24mm exit objective therefore if it had 100% transmission would give you full light transmission at 4x. (24mm / 4x = 6mm) For low light hunting a 4x magnification is plenty for 200 yard shots. Surely the light gathering of the binos to first confirm the quality of the animal is going to dictate a relatively close shot like that anyway.
So all things being equal, that Swaro 1-6x24mm is going to give you just as much light gathering as your eye can handle at 4x in twilight as a $4000 swaro 4-16x50mm would at 8x. The question is would you actually need 8x in low light? You’d miss the animal trying to search for it so you’d just crank that giant telescope down to 4x anyway and all that light gathering is lost, non-absorbable by your pupil anyway.
But then we go to mid-day hunting and spot-and-stalk shooting off sticks. 99% of missed opportunities are spent “f-ing around on the sticks”. Fuddling with the zoom. Trying to get your face off the comb to look through a giant telescope of an optic. Being unable to take a snap shot instinctively on an animal that may be moving. When the moment is right hesitation is the road to ruin. The straight tube scopes give you so much more advantages for speed of target acquisition and speed at which you can be ready to pull the trigger.
Last bonus for straight tube scopes. You can fit them in extra low rings. That means your stock‘s comb fits to your face like iron sights. Which means better shooting form. Which means less recoil punching you in the face. It allows a person to shoot a lot bigger gun comfortably than the typical rambo-benchrest American rifle with a high comb, high rings, and a giant optic. My ten year old weighs 100lbs and has a 1-6x24mm on his dangerous game rifle in 375HH and has no trouble shooting it from a darkened blind for crocs, or for kudu, zebra, eland, impala, wildebeest and other plains game out at reasonable adult shooting distances off sticks.
So, more info than you asked for, but there’s a reason that really high end stalking rifles and dangerous game rifles almost always have straight tube scopes. You give up virtually nothing and you gain a lot.
