The Sony A9 III is an excellent full-frame mirrorless camera. When choosing an optimal flash, consider these options:

1. Sony HVL-F60RM
- Official Sony flash designed to integrate seamlessly with the A9 III
- Guide number of 60m at ISO 100
- Wireless radio control for off-camera use
- Quick, quiet recycling and stable continuous performance
- Ideal if you want maximum compatibility and performance

2. Godox V1-S
- Round head design for natural catchlights and even illumination
- Powerful guide number of 60m at ISO 100
- Wireless 2.4GHz radio transmission with TTL auto exposure
- More affordable than the Sony while delivering great performance
- Good option if you want great bang for your buck

3. Profoto A10
- Premium compact studio light with AirTTL support for Sony
- Round head with soft, gradual light falloff
- Powerful with 76Ws output despite small size
- Fastest full power recycling of 1 second
- Go with this if you want top-tier pro flash performance and quality

Profoto A10 or Sony HVL-F60RM2

If u need a high-end studio light, the best choice is Profit A10.