Question about Elinchrom Compact BRX 500

A little late, but still for your information:
The maximum shutter speed (i.e. slow shutter speeds) are of course unlimited.
The flash itself flashes in briefly, shorter than 1/1000s, exact spec of the flash here:
https://www.profotshop.ch/pi...

The typical question is the fastest shutter speed, and that depends on the camera.
The so-called synch speed is limited, especially with SLRs with focal plane shutter, and is 1/250s or slower, depending on the camera type. For faster shutter speeds, Elinchrom offers a special high-speed sync mode, but the BRX flashes are NOT compatible with it. In my opinion, however, high-speed sync is overrated because, no matter how it is used, it is still quite limited by considerable loss of flash power.
There are small compact cameras with electronic global shutter (e.g. Canon G5x) that don't even have the focal plane sync problem. With these you can take flash photos in normal mode (without HS mode) even with 1/1000s exposure time. (I have tried 1/500s myself so far).

Hello, for studio flash set a shutter speed of 1/125 or 1/160.