Tolong jelaskan mengenai Shutter dari Sony alpha a99

Kecepatan Shutter: Still images: 1/8000 to 30 sec, Bulb Movies: 1/8000 to 1/4 (1/3 step), up to 1/60 in AUTO mode (up to 1/30 in Auto Slow Shutter mode)

Tipe Shutter: Electronically controlled, vertical-traverse, focal-plane type