I’ll soon shoot studio portraits with my Chamonix 45 H1. The lens is in a Copal 1 shutter, so its maximum shutter speed is 1/400. I’lm using FP4 plus film.
Can I shoot at that 1/400 so as to kill the studio’s ambient lighting and rely solely on the strobes?
Yeah, but very bright highlights (a touch of sunlight here and there) may still come through. Your best bet is to block out most of the extraneous light so that the strobes dominate the exposure anyway.
Personally I like to keep shutter speeds below 1/00 because of the "just in case" factor of old shutters perhaps not syncing perfectly anymore...
That meter will measure all the light, corded or not corded. When you measure the ambient light in the studio, set up for your portraits and at the ISO for your film, what reading do you get?