A 384 thermal scope uses a sensor that is 384 pixels wide and 288 tall, about 110,000 pixels in total. That is roughly a third of a 640x512 sensor. For a lot of hunters it is plenty: coyotes inside a couple hundred yards, hogs coming to a feeder, or a predator hunt in brushy country where shots stay close.
A smaller sensor means a smaller, lighter unit and a lower cost of entry into thermal. The tradeoff is detail at distance. As you zoom in on a 384 image, it gets blocky sooner than a 640 or 1280 sensor, so it is harder to tell a coyote from a fox or a sow from a boar far out. If most of your shots are inside the range you can identify, 384 does the job.
Lens size matters as much as resolution. A 25mm lens gives a wide view for close work, while 35mm and 50mm lenses narrow the view and bring distant animals closer. If you want more pixels for open fields, compare these against the 640 and 1280 options on our thermal scopes with LRF page.
Pick based on how you hunt. The Nocpix SLIM L25 384x288 is a 2-in-1 that switches between riflescope and handheld, which suits a hunter who wants one unit. The NOCPIX Rico 3 L35R adds a 35mm lens and a rangefinder for hunters who want to range from the rifle.
It is the size of the thermal sensor: 384 pixels across and 288 pixels high. Each pixel reads heat from one spot in the scene, so more pixels means more detail. A 384x288 sensor has about 110,000 pixels, compared with roughly 327,000 on a 640x512 sensor.
The 384x288 number is the sensor's native resolution. The display inside the eyepiece usually has more pixels than the sensor, so the scope scales the thermal image up to fill it. That makes the picture look smooth, but it does not add heat detail the sensor didn't capture.
A 640x512 sensor has close to three times as many pixels, so the image holds detail longer when you zoom and lets you identify animals farther out. A 384 unit is usually smaller and costs less. For close cover and shorter shots, many hunters never feel the difference.