Every anchor that produces a HuntGrade is published on this page, and every score is arithmetic you can repeat. Check our math — that's the point.
Two real scopes from the catalog. Average their three published scores into one number and they land on the same number — but they are opposite bets: a premium name with top-tier glass and handling carrying the only D warranty in the catalog, against a budget scope that's middling everywhere yet better-promised. The single number can't tell you which risk you're taking. The profile can.
Almost every spec on a thermal has an obvious better: more resolution, longer battery life, less weight. Those go into the grades. Lens size is the exception — bigger glass picks up animals farther away, smaller glass shows you more of the field, and which one is "better" depends on whether you hunt open country or close timber. So lens size isn't included in the grade — instead, we show you exactly what each size trades away.
Every thermal makes the same trade: a bigger lens picks up a coyote farther away, but shows you a narrower field of view. Each curve is one sensor class — choose a lens size and you've chosen your spot on it. A sharper sensor moves you to a better curve; nothing escapes the trade.
These yardages are our math, not the brochure's: the distance a coyote-sized animal first shows up as a warm spot on screen (textbook detection criterion, 12 µm pixels). Knowing exactly what animal you're looking at takes roughly 8× closer. Weather and sensor sensitivity can only shorten these. Lens sizes marked on the 640-class curve.
No hunter wants a dimmer display or a heavier scope — there's no trade to weigh, so these specs go straight into the grades. Lens size stays out; it just moves you along the curve at left. Its one real cost is ounces: bigger glass weighs more, and the weight is included in the grade.
A spec sheet lists core resolution, pixel pitch, lens size, and base magnification as if they were four separate selling points. They aren't — they're one geometry. The core sets a fixed budget of pixels. Pixel pitch (the physical size of each pixel) and lens size decide how that budget is spent: across a wide field of view, or packed tight for detail at distance. Magnification just reports how big the result is painted in the eyepiece. The four steps below walk that ladder with real scopes from our rankings, measured two ways — the field of view (FOV: how wide you can see at 100 yards), and how many pixels land across a coyote at 200.
The detail column above is a number; here it is as a picture — the same coyote at 200 yards, drawn at each rung of the ladder. Every frame covers the same patch of ground; the only thing that changes is how many pixels land on the animal. Detail scales with distance: step out to 300 yards and 12 px falls to 8.
And digital zoom can’t add to that count — it crops the center of the FOV and paints the same pixels bigger:
These frames are geometry only — the pixels the sensor samples, simulated from core, pitch, and lens, with rendering quality deliberately left out. Sensitivity, glass, processing, and the display decide how cleanly those pixels reach your eye, and that is exactly what the Image grade below measures.
FOV (field of view) = the width you can see at 100 yards, in feet. Coyote detail = pixels across a 30-inch coyote body at 200 yards. Both are pure geometry from core, pitch, and lens — our math, not the brochure's.
Each grade is built from a few specs, and the weights below are published and fixed. Every spec converts to points on a fixed anchor curve — each card publishes the conversion, and the worked example below repeats the arithmetic end to end so you can check it. Price isn't part of any of them — an expensive scope earns nothing just for costing more. What you get for your money has its own score, further down the page.
What you actually see through the scope. Three specs set it: the detail the sensor resolves, the faintest heat difference it can show, and the screen that puts it all in front of your eye.
Resolution does more for what you see than any other spec, so it carries half the grade. Every core is scored by its total pixel count on a scale that flattens as it climbs — each doubling buys a little less image than the last. The class is just the bracket; the points come from the exact core inside.
Sensitivity earns its keep in humidity, fog and the dawn hour, when everything reads the same temperature. Below about 25 mK you stop noticing the difference on a clear night, so the points flatten as the number drops — a 40 mK core with good processing still reads as a strong field image.
Every minute behind the scope is spent looking at this small internal screen, so its quality counts. But a good OLED at 640×480 is already a clear sight picture, so the floor sits high and the extra resolution on premium panels refines the view rather than transforming it.
Whether you can live with it on a rifle, all night. The grade covers the housing that takes recoil and weather, the ounces it adds to the rifle, the hours a battery lasts, and the eye relief that keeps your brow safe.
The one score that's judged rather than computed, set in three tiers from the maker's own documentation: MIL-STD or machined billet earns 96, IP67 rifle-rated 90, weather-resistant IPX7 71.
Weighed as the scope sits on the rifle, ready to fire — where a maker's published weight leaves out the mount you're forced to buy, we add a flat +5 oz reference mount, the same constant for everyone, and keep the listed figure for audit. Ounces convert on a curve where 16 oz is anchored at 85 and each doubling costs 30 points; lighter is always better.
Hours on one battery convert on a curve — 4 h is anchored at 29 points, 8 h at 70, 13 h at 99 — because swapping batteries at 2 a.m. is the most-cited frustration in owner reports.
Millimeters convert on a straight line — 27 mm is anchored at 20 points, 60 mm at 76 — because eye relief that's too short on a recoiling rifle is a safety problem before it's a comfort problem.
What the maker promises in writing for the day the electronics die. The written terms are the only part of the promise you can hold them to, so the grade comes from those terms alone.
The famous "lifetime" warranties usually carve out the thermal electronics, so what counts is the years the electronics are covered: 2 years is anchored at 30 points, 6 at 88, on the stepped ladder above.
Coverage that follows the scope to its next owner is worth real money on resale. Warranties you have to register for count at full value — registering takes five minutes, so we assume you will.
Every number above is published, so each grade is just arithmetic you can repeat. Here are all three for the N-Vision Halo XRF, computed start to finish — a proven 640-class core behind a modest display, a short eye box, and a standout warranty. One scope, three separate reads.
A $2,000 scope and an $8,000 scope are graded on the same curves. What you get per dollar is its own score — shown as a "value pick" tag and a sort, never mixed into the grades.
Each figure is tagged by how we got it. Where a maker won't publish a spec, we work out the right number ourselves and label it — we fill the gap, we don't guess silently or punish the blank.
Brands quote sensitivity (NETD) two different ways, and the after-processing version can't be compared across brands — each brand grades its own homework. We use the comparable figure, tell you which one it was, and flag the uncertainty instead of hiding it.
The spec-sheet "detection range" is measured against a standing man in perfect conditions. We compute our own ranges against the animals you actually hunt — coyote, hog, whitetail — at a stricter standard, and call them what they are: a best-case ceiling, not a promise.
No sponsored placements, no manufacturer money, methodology published. Where the site carries retail links they are clearly disclosed and have zero influence on any grade — the grade is computed before the link exists.
These are two different things, kept apart on purpose. The score is anchored and absolute — a 1024×1024 core is worth 92 today and in ten years, and nothing already scored ever silently re-scores. The letter grade is the opposite: it ranks a scope against the entire current field, so it answers "how does this stack up against everything on the market right now." As the field advances, a scope's score holds still but its letter slips — today's A is tomorrow's C, even though the number never moved. A top-tier scope from 2019 still earns its old score; it just no longer earns the A. The score is the measurement; the grade is the standing.
Anchors are fixed; the methodology itself still improves. When it changes, the change is logged here with its reasoning — never applied silently. Two kinds of changes earn an entry: changes to the math, which bump the version, and changes to how the published numbers should be read, which don't. Design polish never qualifies.