How to choose a Guide thermal
Form factor
Start with the job. A thermal riflescope, from the TU 3.0 and Nova series, replaces your day optic. An Orion 2-in-1 or a TB clip-on mounts in front of the day scope you already own, and the Orion also works handheld. The TE, TD and Kodiak monoculars are scouting tools you sweep across a field, and the TN and DN binoculars spare your eyes on a long sit.
Sensor and rangefinder
Then choose the sensor. A 256x192 sensor, as in the TE211, suits close-to-medium scouting, 400-class and 640-class sensors show more detail at distance, and the TU1250M carries Guide's 1280-class sensor at the top of the range. Last, decide on a laser rangefinder: none, a built-in LRF, or Guide's in-lens LRF, which sits inside the objective and which Guide says minimizes parallax error.
Frequently Asked Questions
Should I buy a thermal scope or a thermal monocular first?
For most hunters, the monocular. It scans a field by hand to find warm animals, and the scope comes second, once you know what you are looking at.
What does NETD mean?
Thermal sensitivity: the smallest temperature difference the sensor can show, in millikelvins. Lower is better. Guide rates its TU Pro 3.0 LS models at 15 mK and most TU 3.0 scopes at 18 to 20 mK.
Is thermal hunting legal?
It varies by state and by species, so check with your state wildlife agency before you go.
To decide which to buy first, read Thermal Scope vs Thermal Monocular, and for the specs, Thermal Imaging Specs Explained.