Every thermal spec sheet lists three ranges. Most people read the biggest one and assume that's how far the optic works. It isn't, and the gap between those numbers is where a lot of bad shots come from.

**Detection** — the distance where you can tell something warm is out there. That's it. A heat source shows up as a bright spot with no usable shape. Could be a coyote. Could be a raccoon. Could be a rock that soaked up sun all afternoon and is still giving it back. Detection tells you where to point your attention, nothing more.

**Recognition** — close enough that the blob has a shape. You can tell it's a four-legged animal instead of a bird or a person, and you can get a rough read on body size. Head shape and gait start showing up.

Recognition is not identification, and this is where people get in trouble. Knowing something is dog-sized doesn't tell you if it's a coyote or somebody's lab that got out.

**Identification** — you can confirm what it is and see enough body detail to place a shot. Muzzle, ears, tail, how it moves. The doubt is gone.

Identification is your actual working range. Everything shorter than that is scanning.

**Where the numbers come from**

The ranges aren't field-tested. They're calculated from how many sensor pixels the animal covers at a given distance. Far away, an animal covers a pixel or two — enough to register heat, not enough to have a shape. As it gets closer it covers more pixels and detail fills in. Each tier has a minimum pixel count, and the manufacturer publishes the distance where a standard-size target hits that threshold.

Nobody walks a coyote across a field to verify it.

**Why real distances come up short**

Those calculations assume clear dry air, strong temperature contrast, and a standardized target that's usually a lot bigger than what you're actually hunting. Humidity, rain, fog, and dust all eat infrared before it reaches the sensor. A warm night shrinks the gap between the animal and the ground. And a coyote presents way less surface area than the reference target.

All of that pushes your real numbers shorter than the sheet.

**The practical version**

Read the spec sheet right to left. Start at identification range, knock it down for your conditions and your target size, and treat what's left as your honest working distance. Detection range is scanning margin.

Two optics with the same detection number can have very different identification ranges depending on sensor resolution and lens size. That's the comparison worth making.

Also worth knowing: manufacturers don't all calculate this the same way. Target size assumptions and conditions vary. DRI figures are decent for comparing models within one brand and pretty unreliable across brands.

Detection vs Recognition vs Identification (DRI): what those three numbers on the spec sheet actually mean