No problem. Sync speed is the maximum speed in which your shutter can sync with your flash before requiring high speed sync, which reduces power efficiency of your flash. The way it works is that under your sync speed, your first curtain opens, exposing the sensor at the time of your flash; and then your second curtain closes behind it. In high speed sync your first and second curtain move over the sensor at the same time, which requires your flash to “pulsate” at an incredibly high speed to expose the entire frame. This leads to less power in your flash output. The only use case for high-speed saying is when you are working in very bright conditions, and you want to maintain a shallow f-stop, which requires a high shutter speed. To use high-speed saying he will need a compatible light system, which most modern ones are these days.
