LRF (Laser Rangefinders) are becoming more and more prevalent on thermal scopes because judging distances at night is very difficult. I get the following question a lot, so thought I would share it here as well. There are a few tips I tell people if you don't have an LRF at least for coyote hunting.

Thermal Shading: This is a technique that I have used for years. The degree to which this works can very depending on the resolution and base magnification of your scope. If using a 1x thermal, this isn't going to apply nearly as much, or it will happen at much closer ranges. Thermal shading is noticing the heat differences of the coyote's body. A coyote loses heat through the head and lower legs the most. When a coyote is all one color, on most thermals, it is past the shooting distance where you can hold right on your spot (PBR). As the coyote gets closer, you will often notice the legs and head becoming a different color than the rest of the coyote, and eventually you will start to notice this on the body of the coyote as well. When you can start seeing thermal shading in the body of the coyote, it is within range of most modern center-fire cartridges. This is an example at some different yardages:



Reticle Proportion: Another technique is set up a target at known distances of a coyote. You can use HVAC tape to make an outline for instance or at least the distance from the ground to the shoulder or the nose to the tail, etc. Use your favorite reticle and see how large the coyote is in the scope at given distances. The reticle chosen, whether it is a FFP or SFP reticle and the magnification level (if not a FFP), can all make a difference.

Good lesson.  I am still learning distance estimation with thermals.  I like the thermal shading examples.

This is a very useful tip.
Thanks!