A camera SDK (Software Development Kit) is the manufacturer's own programming interface for talking to their cameras — the proprietary path that exists beyond ONVIF. Where ONVIF gives a common baseline across brands, an SDK exposes the full, vendor-specific feature set: every imaging parameter, the camera's unique analytics, precise PTZ behaviours, firmware and device management, and features too new or too specialised to be in the standard yet. Axis, Hanwha, Hikvision, Dahua, Bosch and others each publish one.
The SDK is what you reach for when the open standard runs out. ONVIF might stream the video and report basic events, but to configure a camera's on-board AI, drive an advanced PTZ tour exactly, or pull a proprietary metadata feed, the VMS often must speak the vendor's SDK directly. This is the practical meaning of the ONVIF "baseline vs full features" boundary: standard for interoperability, SDK for everything the vendor does beyond it.
The trade-off — and the pitfall — is lock-in. Integrating against a vendor SDK ties that part of your system to that vendor: deeper features, but a custom integration to maintain and a harder path to swap brands later. Good designs use ONVIF for the broad, interchangeable baseline and reserve SDK integration for the specific cameras whose unique capabilities justify the coupling, with eyes open to the maintenance and lock-in cost.
