just 3/8" isn't sufficient. There should be a diameter *and* something to describe the thread - either pitch - 20 (threads per inch), or a code to describe what the screw form is. UNC (Unified Coarse thread) / UNF (Unified fine thread) / BSP (British Standard Pipe) etc.,
The wrong threads per inch could screw in a turn or two but wouldn't be safe and could chew up the thread on the bottom of the camera. The different thread forms have different angles and radius'.
I will try and work out exactly what thread it is later today.