At the last wedding reception I did I used my 5D mk3 with the new Rode video mic (the stubby one) to capture the very loud music etc. The 5D was in audio Auto mode and as the music was loud I tripped the switch on the Rode to reduce the input by 20db (I think its that)

The audio was still blown out. Am I being unrealistic to think this setup isnt appropriate in this type of environment?

Dan I always use manual audio with the 5D Mark 3 be sure to check the led to make sure you are not in the red. Also for a safe guad record 20sec and playit it back to check the audio.

Any auto-level audio system is likely to be defeated by very loud noise levels. You need a system that includes a limiter to avoid distorted peaks. The 5D3 does not include a limiter. It's generally better to record manually.

I believe that the new JuicedLink box records the the mic you have plugged into it at regular volume on the left channel and -10dB on the right just incase you're ever in a scenario where something is getting blown out. Now you'd have a way to fix it in post. Something like this might work for you if you like to record in auto.

Thanks for the replies. I use a Zacuto EVF via the HDMI which can display audio meters but unfortunately the 5mk3 doesnt send the audio via the HDMI (apparently) so have no way of monitoring on the go.

Thanks for the replies. I use a Zacuto EVF via the HDMI which can display audio meters but unfortunately the 5mk3 doesnt send the audio via the HDMI (apparently) so have no way of monitoring on the go.

One of the 5D MKlll's awesome new features is you most certainly can monitor audio through earphones directly from the camera, and levels on the LCD via the info menu.

Thanks Charles, when you have an external monitor plugged into the Mk3 the LCD switches off.

I think what Charles was pointing out is that even when the HDMI diverts the video from the LCD screen, the audio from the headphone jack is still active... that's how I monitor my audio.
I use a SmallHD monitor (which as you said, defeats the built-in LCD screen on the camera) and monitor audio with headphones via the headphone jack on the camera.

Even with the external monitor, you can hit the "Q" button to see the levels when you need to.

The headphone jack is not active during playback with HDMI plugged in however... only while recording.

Thanks John, I'll check out the 'Q' button