Using the Edutige EIM-003 Plus an iPhone as a Separate Audio Recorder
Here's a video about how you can use an Edutige EIM-003 microphone plus an iPhone as an external audio recorder for videos. Why would you want to do this? Mainly to improve audio quality by placing the microphone closer to the audio source. Check out the difference between the camera's built-in microphone and the EIM-003 and iPhone combo.
