Pulsar · Krypton 2 FXG50

Estimated range, standing human, clear air

IdentifyRecognizeDetectBox claim

Pulsar Krypton 2 FXG50640×480 · 12 µm · 50 mm

160 m identify260 m recognize1,042 m detectbox says 2,300 m (1.8 m object)

501002005001k2k5k m

Estimated from pixel pitch and lens focal length using the Johnson criteria (2, 8 and 13 pixels across a 0.5 m human critical dimension), clear air, 50 % probability. A model of the optics, not a measurement — real range depends on temperature contrast, humidity and the animal.

Pulsar

Pulsar Krypton 2 FXG50

Clip-on640-class

The Pulsar Krypton 2 FXG50 is a 640×480, 12 µm thermal clip-on behind a 50 mm lens. On the Johnson yardstick that is an estimated 1,042 m detection and 260 m recognition range for a standing person; Pulsar quotes 2,300 m detection (1.8 m object). At 20.5 oz it is 9th-lightest of the 10 clip-ons here, where the median is 19.4 oz.

Approx. price: ~$5,000
Sensor: 640×480 · 12 µm
Lens: 50 mm · 1×
Est. detection: 1,042 m · 1,140 yd

Best for

Keeping your day scope and its zero while adding thermal at night

We may earn a commission. Price and availability on Pulsar’s site may differ.

Box claim vs. what the optics support

Manufacturer says

2,300 m

detection, 1.8 m object

Johnson estimate

1,042 m

detect · 260 m recognize · 160 m identify

Claim ÷ estimate

2.2×

how much further the box reaches than a 2-pixel, 0.5 m criterion

One pixel of this unit sees 0.240 mrad (12 µm ÷ 50 mm). Two pixels across a 0.5 m human is 0.5 ÷ (2 × 0.240) × 1000 = 1,042 m. The box figure is usually computed against a person’s 1.8 m height instead, which is why it comes out higher. Full explanation.

Specifications

Manufacturer-published figures, cross-checked against pulsarnv.com, pulsarvision.com, predatorhunteroutdoors.com.

Sensor: 640×480
Pixel pitch: 12 µm
NETD: <40 mK
Refresh rate: 50 Hz
Lens: 50 mm
Base magnification: 1×
Field of view: 8.8° horizontal
Display: 1920x1080 AMOLED
Claimed detection: 2,300 m
Claim basis: 1.8 m object
Run time: 11 h
Battery type: Removable pack
Weight: 20.5 oz
Length: 5.2″
Laser rangefinder: No
Ballistic calculator: No
Records video: Yes
Wi-Fi: Yes
IP rating: IPX7
Warranty: 3 years (5 with registration)
Approx. price: ~$5,000

Derived here

IFOV: 0.240 mrad
Est. detection: 1,042 m
Est. recognition: 260 m
Est. identification: 160 m
Claim ÷ estimate: 2.2×
Derived field of view: 8.8°
Pixels per degree: 72.9

Features

640 sensor
12 µm
50 mm lens
50 Hz
Removable battery
Records video
Wi-Fi
IPX7
AMOLED display

What the spec sheet says

Read from the published specifications and this catalog’s own numbers — not from owner reports, which we have not collected for this unit.

For it

640×480 core — 2.8× the pixels of a 384-class unit
12 µm pitch — the 50 mm lens sees what a 17 µm core would need 71 mm to match
Removable battery pack — a spare in the pocket doubles the run time
11 h published run time, 3rd-longest of 64 here
IPX7 sealed — survives immersion, not just rain
Records video and streams to a phone over Wi-Fi
Detection claim is only 2.2× our estimate — one of the more conservative box figures here

Against it