Question: What are your experiences with optical gas imaging cameras?

The caption on the lead image reads:

Stills taken from the optical gas imaging camera video that show what the human eye sees (left) compared to the emissions shown when the camera is switched to infrared mode (right).

This image was in a great email that came in today from the New York State Department of Conservation: https://content.govdelivery.com/accounts/NYSDEC/bulletins/1d463fd

Here's what they say:

Air Resources staff use an optical gas imaging camera to shed some light on previously invisible air pollution. This video camera allows our staff to see reflected infrared radiation from certain air contaminants. They can use the camera to identify leaks or malfunctioning equipment at air pollution sources, and record real-time pictures and videos to document any issues. The optical gas imaging camera is a valuable tool because it allows identification of pollutants being emitted that would otherwise be invisible to the human eye. Ultimately, the camera helps us to evaluate a facility to find and fix any problems quickly, which helps to keep our air clean.

Has anyone else used one of these?