These are the slo-mo guys.

https://www.youtube.com/@theslowmoguys

They have been around for a while and do some very interesting stuff with some very high speed cameras, with guns and explosives.

Another interesting pair is Ballistic High speed. The also have some very high speed camera's. They are more focused on tactical stuff. They one time set up a bowling ball mortar to shoot a ballistic gel dummy. As the former owner of a bowling ball mortar, the was a very frightening video.

https://www.youtube.com/@BallisticHighSpeed