FAQ
Hunting Optics: Frequently Asked Questions
Short, direct answers to the questions hunters actually search for, with a link to the longer version where there is one.
About hunting optics
What does 10x42 mean on a pair of binoculars?
10x is the magnification - the image looks ten times closer than with the naked eye. 42 is the diameter of the front (objective) lens in millimeters, which sets how much light the binocular collects. Divide the second by the first and you get the exit pupil, 4.2 mm, which is the most useful derived number for low-light use. Full explainer.
What magnification should I buy for hunting?
8x for timber, cover and whitetail. 10x for mixed country, which is why it is the default. 12x or 15x only if you will genuinely carry a tripod, because above about 10x handheld shake costs you more detail than the magnification gains. 8x42 vs 10x42 in detail.
What is exit pupil and why does it matter?
Exit pupil is objective diameter divided by magnification, measured in millimeters - the width of the light column leaving the eyepiece. Your own pupil opens to roughly 5-7 mm in low light, so a binocular with a 5.25 mm exit pupil feeds your eye more usable light at dusk than one with 4.2 mm. It is fixed by the format, not by the price. With the arithmetic.
What is twilight factor?
The square root of magnification multiplied by objective diameter - about 20.5 for a 10x42, 18.3 for an 8x42. It is a crude single figure for low-light detail resolution, and it moves in the opposite direction from exit pupil, which is why neither number alone decides anything. Both, properly explained.
How much should I spend on hunting binoculars?
Around $250 if you hunt timber and close country - that genuinely covers it. Around $500 if last light and open terrain matter to you. Above that only if you already know specifically what you are missing, because the returns get small fast. The economics, honestly.
Are expensive binoculars worth it?
The jump from $120 to $250 is enormous. $250 to $500 is real and worth it for low light. $500 to $1,500 is a small, genuine improvement that most hunters will not notice in the field. Anyone describing that last step as transformative is selling something. We make the case here.
Do I need ED or HD glass?
Need, no. ED glass uses extra-low-dispersion elements to cut the color fringing that makes a dark animal against bright brush look mushy. It matters most at high magnification and in flat light. HD is a marketing term rather than a standard, and different brands mean different things by it. What each label actually means.
What is angle compensation on a rangefinder?
It converts the straight-line distance the laser measures into the horizontal distance, which is what gravity actually acts over and what your pins or turret are calibrated for. From a treestand or across a slope those two numbers differ enough to miss over. It is the single most important feature on a hunting rangefinder. Full explanation with the trigonometry.
Why does my rangefinder not reach its advertised range?
Because the advertised figure was measured against a highly reflective target like a road sign or a rock face. Deer hide reflects poorly, so a unit rated 1,400 yards reflective is typically good for a few hundred yards on a dark animal. That is physics, not a defect. What accuracy and range figures mean.
Can I use a golf rangefinder for hunting?
It will measure distance, but most golf units optimize for the nearest reflective object - the flag - which is the opposite of what you want with brush between you and the animal, and many lack hunting-style angle compensation. The differences in full.
Should I buy a rangefinder or rangefinding binoculars?
Rangefinding binoculars remove the one-handed juggle and the second item on your chest, at the cost of weight, money, and a single point of failure. A separate rangefinder is cheaper and lets you keep binoculars you already like. The comparison.
Do I actually need a spotting scope?
Only if you need to judge antler or horn at over about 600 yards before committing to a stalk. If you hunt timber, or everything you shoot at is inside 300 yards, good binoculars do the job and weigh five pounds less. Worked through here.
Angled or straight spotting scope?
Angled is more comfortable seated for long sessions and works with a shorter tripod; straight is faster to get on a target and better from prone or a vehicle window. Most western hunters end up angled. The full comparison.
Do I need a tripod for binoculars?
Not at 8x or 10x. At 12x and above, yes - a shaky 12x shows you less than a steady 10x, so the tripod becomes part of the optic rather than an accessory. Where the threshold is.
Is a bino harness worth it?
It is the best value upgrade in optics. A $29 harness holds the binoculars against your chest, keeps rain and brush off them, and stops the swinging that makes people leave glass in the truck. It improves any binocular more than the next $100 of glass would. Our picks.
How do I clean binocular lenses without damaging them?
Blow the grit off first - never wipe dry grit, because that is what causes permanent fine scratches - then use a wipe or cloth made for coated optics in a light circular motion. A shirt tail is the most common way good coatings get ruined. The full method.
Is a monocular good enough for hunting?
As a pocketable second optic for quick confirming looks, yes. As your only glassing optic, no - one eye tires faster, you lose depth perception, and scanning is slower. The honest comparison.
Are thermal monoculars legal for hunting?
It depends entirely on your state and the species. Several states permit thermal for hogs and coyotes while prohibiting it for big game, and the rules change. Check your current state regulations before buying, and treat nothing on this site as legal advice.
About this site
Have you tested the products you recommend?
No, and we say so on every page. We do not run a testing lab. What we do is apply one published set of ranking criteria, read specifications off each manufacturer's own page with the date we read them, compute the optical arithmetic ourselves with the formulas shown, and attribute everything else to named sources. The method in full.
How do you make money?
Affiliate commission. When you buy through a link here the retailer pays us a percentage, and you pay the same price you would have paid anyway. There is no advertising and no sponsored content on this site. Full disclosure.
Does commission affect your rankings?
No, and the mechanism is what matters rather than the promise: the criteria and their weights are published before the picks, and every product card shows its score against each one. A commission-driven ordering would be visible as a mismatch with our own stated rules. In practice we recommend the cheaper option repeatedly.
Why do some prices say 'Check price' instead of showing a number?
Because our price data for that product is either missing or older than 48 hours. Prices on this site expire on their own rather than going stale, so the failure mode is silence instead of a wrong figure. The number you see at the retailer is always the one that applies.
Who publishes Glass & Ridge?
Iron Mako Media. Articles are written by Mike M., the hands-on owner behind it. More on the about page.
Question not answered here? Ask us, or start with the upgrade guide and the glossary.