Based on standard industry practices and the provided reference, you typically only need genlock if you are feeding live video from multiple cameras into a switcher for instantaneous cuts or dissolves.
When is Genlock Necessary?
Genlock, short for "generator locking," is a process that synchronizes the video output of multiple devices to a single timing reference signal. This is crucial in multi-camera live production environments.
When cameras are genlocked, their video frames are aligned precisely in time. This allows a video switcher to seamlessly transition between cameras without glitches, stutters, or synchronization errors (like screen tearing or frame jumps) that would occur if the camera outputs were slightly out of phase.
As stated in the reference:
You don't need Gen Lock unless the cameras are feeding live video to a switcher (to my knowledge) so just Jam throughout the day and you will be fine.
This highlights the primary use case: live, multi-camera switching.
Key Scenario for Genlock:
- Live Multi-Camera Switching: If you are using multiple cameras and sending their feeds directly to a production switcher (like a Blackmagic ATEM, Roland V-series, etc.) for live broadcast, streaming, or recording with real-time cuts, genlock is essential for professional results.
Genlock vs. Jam Sync
It's important to differentiate genlock from jam sync (or timecode jamming). While both involve synchronization, they address different aspects:
- Genlock: Synchronizes the video output signal timing between devices. Ensures frames arrive at the switcher simultaneously.
- Jam Sync (Timecode): Synchronizes the internal clocks of devices to the same timecode value. This is vital for post-production, making it easy to align footage from different cameras on a timeline, but it doesn't align the actual video output streams for live switching.
When Jam Sync is Sufficient
If your workflow involves recording footage from multiple cameras independently and then syncing them in post-production, you typically do not need genlock. Jam sync (synchronizing timecode) is the standard method for this scenario. It allows your editing software to automatically align clips based on their shared timecode, significantly simplifying the editing process.
As the reference suggests, if you are not live switching:
...so just Jam throughout the day and you will be fine.
This confirms that for many common multi-camera recording situations where editing happens later, jamming timecode is the appropriate and sufficient method.
In summary, assess your specific production workflow. If you are live switching multiple cameras, genlock is required. If you are recording footage for post-production editing, timecode jam sync is usually all you need.
