Yes, the Sony a9 features an electronic shutter that allows for completely silent shooting at up to 1/32,000 sec, making it perfect for golf, tennis, or quiet ceremonies.
Using the NP-FZ100 battery, the Sony a9 is CIPA-rated for approximately 480 shots using the viewfinder or 650 shots using the LCD monitor.
The Sony a9 features dust and moisture resistance with extensive sealing throughout the body, though it is not fully waterproof and should be protected during heavy rain.
Yes, it records high-quality 4K video (3840 x 2160) using full pixel readout without pixel binning, oversampling 6K data for exceptional detail.