Athlon Optics Cronus ATS Pro 50L-640 Thermal Scope with LRF

Athlon calls the Cronus ATS Pro 50L-640 its flagship thermal riflescope. It pairs a 640 × 480, 12 μm sensor behind a 50 mm F1.0 lens with a laser rangefinder rated to 1,600 yards and a ballistic calculator that can put the holdover point on the reticle. Next to the Guide TU650LS, it gives up the Guide's 640 × 512 sensor and 14-hour battery for a laser rated farther (1,600 yards against 1,300) and a lower 2.95x starting magnification.

Key Features

• The 50-640's sensor and lens, plus ranging. The 50L-640 shares its 640 × 480 sensor, 50 mm F1.0 lens, 8.8° × 6.6° field of view and 2.95x to 23.6x range with the non-rangefinder Cronus ATS Pro 50-640; the laser rangefinder and ballistic calculator are what it adds. Against the 35L-400, the 50 mm lens puts 0.24 mrad on each pixel instead of 0.34, and the zoom reaches 23.6x instead of 13.2x.
• First focal plane reticles. Athlon's reticle manual lists ten interchangeable reticles, five MOA and five MIL, on the first focal plane, so their subtensions hold at every magnification. Each comes in six colors with ten brightness levels.
• Three ranging modes. Single ranging puts the holdover point on the reticle for the distance just measured. Continuous ranging (5, 10 or 20 seconds) shows the holdover in MOA or MIL instead. Shooting via PIP puts the ranging cursor and data on the main screen and the reticle in the picture-in-picture window. A stadiametric rangefinder is built in as well.
• Ballistics set up in the app. You build rifle and bullet profiles in the Athlon Ballistics app and send them to the scope; in single ranging mode it then shows the holdover point for each distance it measures.

• Ten zeroing profiles and One Shot Zero. Profiles A to J cover different rifles, loads or distances, each zeroed at 50, 100, 200, 300 or 500 yards or meters, and One Shot Zero calibrates the zero in the field.
• Digital zoom and image tools. Zoom runs from 1x to 8x in 0.1x steps, with a quick-zoom button on the zoom knob. Hot track marks the warmest point in the image, picture-in-picture sits at the top left, middle or right, and three scene modes (Natural, Enhanced, Highlight) work with seven color palettes.

• Auto-Shot recording with audio. Switched on, Auto-Shot records a video from 3 seconds before a shot to 7 seconds after, plus five images, with trigger sensitivity in five settings. With the microphone on, any video records sound, and 128 GB of built-in storage holds it all. Eco mode switches off Auto-Shot and Wi-Fi.
• Three batteries. One built-in battery and two external packs. The scope draws on the external pack first, Athlon rates runtime at 10 hours or more, and the USB-C port powers the scope, charges both batteries and transfers files. Keep the internal battery charged: if it is completely flat, the scope will not start on the external battery alone.
• Wi-Fi and video out. 2.4 GHz Wi-Fi streams live video to the Athlon Thermal app with the phone within about 15 yards, and a micro HDMI cable in the box connects an external display.

• Sealed for weather. IP67 and fog-proof, rated to work from -22°F to 122°F, on external power below -4°F.

Who It's For

• Predator and varmint hunters, the uses Athlon names for it, who want ranging, holdover and recording in one optic.
• Shooters moving up from the 35L-400. It uses the same manual, buttons, menus and zeroing system, and the same 1,600-yard rangefinder and three-battery setup. What changes is the 640 × 480 sensor and 50 mm lens, at 42.3 oz against 41.3.
• Buyers choosing among our 50 mm rangefinder scopes. The Guide TU650LS answers with a 640 × 512 sensor rated ≤15 mK, a 14-hour battery and 256 GB of storage at 935 g. The Alpen Apex 640 50mm LRF is the lightest at 632 g and runs up to 15 hours on two batteries, while the Athlon gives you ten zeroing profiles to the Alpen's five and 128 GB of storage to its 32 GB.

Accessories & Compatibility

• Mounting. The scope has a 30 mm tube, and two Picatinny-compatible 30 mm rings come in the box. Athlon does not publish the rings' height.
• Focus. The focus ring on the objective works like the parallax adjustment on a conventional riflescope.
• Extra power. The USB-C port can run the scope from an external power bank on a long night.