This graph shows the signal-to-noise ratio for the Blackmagic Cinema Camera at the old 1.2.1 firmware and the latest 1.5.1. The Nikon D800 is also included as a reference to show what a typical DSLR performance graph like. The recording level was set to -12dBFS.
The old firmware had a sweet spot at 30% gain. This provided an excellent s/n ratio of 65dB with an input level of -43dBu.
The new firmware now has a sweet spot at 80% gain and the s/n ratio has dropped to 60dB which is still quite good. However, the camera now requires a much stronger input signal of -33dBu.
Therefore, with the same input signal of -43dBu, the s/n ratio has dropped by 15dB which is quite significant. Definitely a step in the wrong direction.
Also, the frequency response now has a sharp roll off under 1kHz. This is also not good but can be fixed in post with some equalization.
Blackmagic is aware of these issues and will hopefully have a fix soon.
In the meantime, we recommend that you set the camera to 80 to 100% gain and feed the camera a very hot signal. When using our passive DXA-BMD adapter, set the level to +3dB on the VU meter. Since this adapter does not have a preamp, you should only use high output mics like the Sennheiser wireless or an amplified signal from a mixer.
You can also use our active DXA-SLR MINI or DXA-SLR PRO adapters which have built-in low noise preamplifiers and will allow you to get excellent results with other mics. You would simply need a special cable to connect to the two ¼” inputs on this camera.