Abstract: Disclosed is a follow focus. The follow focus includes the gear box, the handwheel assembly and the follow focus assembly. The handwheel assembly includes a handwheel body and an active worm, the active worm is fixed to the handwheel body and extends toward the gear box, and the active worm is provided with a first worm gear; and a follow focus assembly includes a follow focus gear and a driven worm, the driven worm is fixed to the follow focus gear and extends toward the gear box, the driven worm is provided with a second worm gear, an angle between the active worm and the driven worm is 90°, and the first worm gear is meshed with the second worm gear.

Abstract: Disclosed is a mobile phone clip, including: a clamping member, a supporting member, and a base. The clamping member is rotatably connected to the supporting member through a first rotating assembly, the supporting member is rotatably connected to the base through the second rotating assembly, and a third rotating assembly is provided on the base. The second rotating assembly is configured to rotate supporting member to adjust a pitch angle of the mobile phone, the base is provided with a third rotating assembly for connecting an external equipment, and the third rotating assembly is configured to horizontally rotate the base to change an orientation of the mobile phone.

Abstract: Disclosed is a nonferrous magnetic filter system. The nonferrous magnetic filter system includes a filter assembly and an adapter ring. The filter assembly includes a lens ring, a first magnet, a first filter lens and a first clamping ring. The first magnet and the filter lens are firmly pressed and fixed on the lens ring through the first clamping ring. The adapter ring includes a fixing ring, a second magnet and a second clamping ring. The second magnet is firmly pressed and fixed on the fixing ring through the second clamping ring. The filter assembly is configured to be assembled on the adapter ring from a side of the adapter ring through a mutual adsorption of the first magnet and the second magnet.