The shutter speed in <Shutter>.
optional
channelId: number
Zero-based channel; read by the parser, never written by the camera.
optional
shutterLevel: "1/3"
| "1/4"
| "1/5"
| "1/6"
| "1/8"
| "1/12"
| "1/15"
| "1/25"
| "1/30"
| "1/50"
| "1/60"
| "1/100"
| "1/120"
| "1/250"
| "1/500"
| "1/1000"
| "1/2000"
| "1/4000"
| "1/10000"
Shutter speed as a fraction of a second; always written in replies.