Brendan if it fits in the camera mount it's a 1/4 x 20 (20 teeth per inch). Go to any bolt place and ask for a 1/4 stainless steel socket head cap screw 1/2 inch long.
Bunnings do not have a good range of this stuff, any bolt and bearing place should have them or you can buy them online.
https://www.boltandnut.com.au/socket...ews-ansi-b18-3
1/4" x 20 TPI x 1/2" Full Thread UNC Coarse Socket Head Cap Screw (3/16" Key) A4-70 Stainless G316 ANSI B18.3