With the 'HF Legacy' setting you have the option for the PIR sensor of your new - second generation - Reconyx HyperFire cameratrap (only available in the HS2X, HP2X, HP2W, and HL2X) to operate the same as the outdated - first generation - HyperFire models (e.g. HC500, HC550, HC600, PC800, PC850, PC900, SC950). This functionality is especially interesting for professionals already using the first generation HyperFire models. In this way, results can be compared in a responsible manner. If you do not use the HF Legacy setting, you will have a more sensitive PIR sensor with which you can capture animals or people even faster.
The PIR detection zones (red) of the second generation Reconyx HyperFire models (with the exception of the HF2X). These correspond to the first generation Reconyx HyperFire models, but are more sensitive by default. With the HF Legacy setting, the sensitivity of the PIR sensor also corresponds to the first generation HyperFire models.
Cameratraps that feature the HF Legacy functionality: