We have been testing different microphones for the Nikon D800. One of the major problems with shooting on the DSLR are the audio preamplifiers (preamps) on the camera. They’re not designed very well. The camera has a spectacular imager because of the chip size, 1+ inch wide. But without good audio, you really just have a film camera. In order to get around this problem, we purchased 2 inexpensive wireless lavalier microphones, a Pearstone OLM-10 and an Audio Technica. Then we have a Senheiser wireless lavalier microphone, very high quality, and an Audio Technical 875 shotgun routed through a Zoom H4n.
We found that both the Pearstone and Audio Technica wired lavalier mics had an unacceptable level of hiss, at -45dB or higher. This is quite audible, making the recording sound as though it was made on a tape recorder. The D800 input level had to be raised to 10 or 11 to get an acceptable volume for the speaker but, as a consequence, increased the hiss to an audible level.
Then we tried the Senheiser wireless lavalier and increased the receiver preamp output to 3/4 full volume. This allowed us to reduce the D800 input level to 5. Then the hiss dropped to -50dB or lower. At that setting, this hiss became inaudible.
Our final test was routing an XLR Audio Technica 875 Shotgun mic through a Zoom H4n set on an input level of 60 and an earphone output level of 60. We then routed the earphone output into the D800 microphone input and again set it to a level 5. Again, the hiss was not audible, producing an acceptable recording level.
With this test, we found two acceptable solutions to eliminate having a two system recording for using the Nikon D800 as a HD video camera.
The one disadvantage about using a single shotgun on the Zoom H4n is the single shotgun only records on one channel. That’s easily fixed by using dual mono audio in Final Cut Pro X (FCPX). The big advantage is we can get XLR audio into the D800 while making a 48kHz 16-bit perfect simultaneous recording on the Zoom. We even tried it with the built-in stereo mics and had good success with that, too.
The only time we have found the wired lavaliers to work is when we have recorded outside where there is enough ambient noise to drown the hiss. Even though the hiss is there, the SNR (signal to noise ratio) with the ambient makes the hiss fairly inaudible.