Profoto HSS

What is HSS?
High-Speed Sync (HSS) is the technical term for syncing flash with shutter speeds shorter than the so-called x-sync, typically 1/250 of a second. With HSS, you can shoot at shutter speeds up to 1/8000. That means you are in full control of the ambient light, which is useful when shooting outdoors in sunlight.  

What is HSS used for?
Having the option to shoot with flash at a super short shutter speed down to 1/8000s gives you superior control of the ambient light. As an example, it allows you to shoot with a large aperture in bright conditions to achieve a shallow depth without burned out skies. You can also capture super crisp action in mixed light conditions without getting any motion blur from ambient light.

How do I work with High-Speed Sync (HSS) on my Canon camera?
For HSS using an Air Remote TTL: Go to the settings menu, select ‘SYNC’ and then activate ‘Hi-S’. You can now select any shutter speed on the camera and use flash.
For HSS using Profoto A1: Canon cameras will automatically switch to HSS when shooting above the flash sync shutter speed.

How do I work with High-Speed Sync (HSS) on my Nikon camera?
Nikon cameras will automatically switch to HSS when shooting above the flash sync shutter speed.

Does Profoto HSS work with the Canon 1DX model?
Yes.

What’s the difference between freeze/HSS?
You can either “freeze” motion with the flash duration (i.e. Freeze) or the cameras shutter speed (HSS).