Now that I've added a 7D MkII to my u/w water camera collection, I've noticed something strange. Since my 7D was unable to constantly focus while in the video mode, there were no apparent problems with the sound. Since the 7D MkII can continuously focus while shooting, I think the focus motor is generating a sound that is being picked up in the audio. While editing some video taken a few months ago, I've noticed that periodically there are loud clicking sounds. The waveform is very consistent. At first I thought it was one of the video light arms moving, but I get the same sound out of water, while shooting video with the camera in the housing.
I just learned that not all focus motors are created equally. The Canon lens, 17-40 L series has a USM motor, which is supposed to be quieter than other motors.
I've considered moving to a Sigma 17-70mm lens which can do macro. Sigma makes three of the lenses, but of the three lenses, only one will fit into my Ikelite housing because of the diameter, the one that does not have the ultrasonic lens motor. So this lens noise must be a common problem, but I've never heard of it.
If this is the cause, I see two solutions, one is to add background music or ocean sounds to the video to cover up the noises, or go in with the waveform editor, locate every occurrence of the sound and drop the volume to a point where it isn't noticeable. So far that's what I'm doing, but it is a tedious job. I'm using Magix Edit Pro 17 Plus, which has some noise filters, but the duration of these bursts are too long and high in amplitude for the filter to correct.
My question is, are other people experiencing the same thing? Are there other solutions?