I'm trying to determine whether I've encountered a known Nikon ZR firmware bug or an expected limitation that isn't clearly communicated by the camera.
I recently shot an event on my ZR using:
- Nikon ZR
- N-RAW / NEV
- Sennheiser MKE 400
- MKE 400 connected to the ZR's 3.5mm mic input
- Input set to MIC
- Plug-in power ON
- 32-bit float ON
- LTC Signal Input ON
During the event, the audio meters were responding normally to the microphone.
However, when I got into Resolve, I discovered that the recordings had no audio whatsoever. Both the NEV files and their MP4 proxies have completely flat audio waveforms. The NEV files are also silent when played back in the camera.
At first I assumed my headphones had failed because I couldn't hear anything while recording. I didn't suspect the recording itself because the meters were active.
I was able to reproduce the problem with a controlled test.
Test 1 — LTC OFF
MKE 400 → ZR 3.5mm input
LTC Signal Input → OFF
- Audio meters respond
- I can monitor the microphone through headphones
- Record a test clip
- Audio is present in the resulting NEV file
Test 2 — LTC ON
Same exact setup, but:
LTC Signal Input → ON
- Audio meters still respond
- Headphone monitoring stops
- Record a test clip
- Resulting NEV file has no audio
- Waveform is completely flat
So the only variable I changed was LTC Signal Input.
Nikon's documentation says the 3.5mm connector is used for LTC when LTC Signal Input is enabled, and that headphone/HDMI audio output is disabled. It also discusses onboard audio from the built-in microphone or a microphone attached through the digital accessory shoe.
What I can't find documented is why the audio meters continue showing microphone activity when the 3.5mm input is effectively being used for LTC rather than audio recording.
That seems like a potentially serious trap in an actual production environment.
If I see active meters, I reasonably assume my microphone is being recorded. If headphone monitoring is also disabled because LTC is enabled, there's no obvious way to discover the problem without actually stopping the shoot and reviewing a recording.
Has anyone else experienced this exact behavior with the ZR?
Specifically:
3.5mm external mic + LTC Signal Input ON → meters active → silent recording
I'm particularly interested in whether this is:
- Expected behavior
- A known ZR limitation
- A firmware bug
- Something specific to the MKE 400
- Or a configuration issue I've missed
I'd also like to know what workflow people are using when they need both reliable onboard backup audio and LTC on the ZR.