SMALLRIG SR 3639

Half cage for Sony mirrorless cameras

The SmallRig 3639 Half Cage is a lightweight camera cage designed to improve accessory mounting options and provide additional protection for selected Sony Alpha mirrorless cameras. Its half-cage construction keeps the camera relatively compact while creating mounting points for equipment commonly used in photography and video production. It is suitable for handheld shooting, tripod-based setups and camera rigs that require additional accessories without the bulk of a full cage.

Compatibility with selected Sony Alpha models

The cage is designed for the Sony Alpha 7 IV, Alpha 7S III, Alpha 7R IV, Alpha 7R V and Alpha 1. Its shaped construction follows the contours of compatible camera bodies and is intended to preserve access to the camera’s main controls, screen, battery compartment and connectors. Before installation, users should verify the exact camera model and follow the manufacturer’s fitting instructions, as the cage is designed for specific body dimensions rather than universal compatibility.

Secure two-point camera locking

The camera is secured using a 1/4"-20 screw at the bottom and an additional side locking point. This two-point attachment helps reduce unwanted movement or rotation between the camera and cage during handheld operation or when accessories are mounted. Integrated protective padding helps prevent scratches and reduces direct contact between the metal structure and the camera body. The side locking mechanism requires the removal of the camera’s split ring on the left side before installation.

Multiple mounting points for accessories

The cage includes 1/4"-20 threaded holes, ARRI-style 3/8"-16 locating holes and an integrated cold shoe mount. These attachment options allow users to configure a setup with compatible handles, external monitors, microphones, LED lights and other production accessories. The range of mounting positions makes it easier to adapt the camera rig to different recording styles, from compact handheld filming to more elaborate video setups.

Integrated Arca-type quick-release base

A built-in Arca-type plate on the bottom allows convenient attachment to compatible support systems. The design supports quick transitions between handheld operation, tripod use and compatible DJI RS 2, RSC 2, RS 3 and RS 3 Pro stabilizers. Additional 1/4"-20 mounting threads provide options for attaching other compatible plates or support accessories. Compatibility depends on the particular quick-release system and the configuration of the equipment being used.

Compact and lightweight construction

The cage measures approximately 108 × 98.5 × 51.3 mm and weighs around 115 g, with a stated tolerance of ±5 g. Its compact dimensions help keep the overall camera setup manageable while adding mounting flexibility. The construction uses aluminium alloy, stainless steel and silicone components, combining a rigid mounting structure with protective contact surfaces. The black finish is designed to fit discreetly into professional and enthusiast camera setups.

Practical features for video production

A built-in magnetic spanner makes it convenient to access the tool required for mounting and adjustment. The cage can also be used with selected optional accessories, including the SmallRig HDMI cable clamp 3000; compatibility with this clamp varies by camera model, so the manufacturer's compatibility notes should be checked before purchase. The camera itself and separately sold accessories are not included unless explicitly stated in the package contents. The SmallRig 3639 is intended to provide a practical mounting platform while preserving the portability of a mirrorless camera system.

• SmallRig Camera Half Cage (SR 3639)
• Locking Side Plate
• Built-in Magnetic Spanner