Canon 5D Mark II - Dual System Audio the Post-Production Process

I am using the Don Earl Engraved Color Reference Sync SlateWhen shooting with the Canon 5D Mark II, the only way to get great audio is to record it separately. Once production is finished we need to sync the audio and the video back together in post.

If you have taken the time to properly slate footage during production, the process is actually pretty quick and easy. There are, however, a few tricks with the 5D2 but once you get the process down it does not take long at all.

This is my process for syncing audio to the Canon 5D2 recorded separately using the Samson Zoom H4n recorder and Final Cut Pro. 

Step 1 - Find Matching Audio and Video Clips 

If the camera and audio recorder start and stop consistently it is really easy to match audio and video clips once you find the first one because they should progress forward evenly. It is good practice to verbally state the scene and take number before clapping the slate. This way you can audibly hear the scene and take and visually see the scene and take making it obvious which audio clip goes with what video clip. 

Step 2 - Find the Sync Points & Sync

Quickly find the sync in your audio by looking for a sharp spike in the audio.Finding the sync point is easy. In the video, find the frame where the slate closes. In the audio, look for a sharp spike in the waveform and mark in on the clap. 

If I am syncing a bunch of clips I will make a new sequence for each clip and add the full video to the sequence. The reason for separate sequence is so I can batch process everything when I bake in the audio (Step 5). Once the video is in the sequence I will find the sync points and add the audio to tracks A3 & A4. 

Step 3 - The 99.9% Solution

The Canon 5D Mark II does not record at a true 30fps. It is actually recording at its own funky rate 99.9% slower then 30fps. This is a problem. If you sync the dual system audio at the beginning of the clip after about a minute you will notice your audio is way out of sync. 

Setting the speed of your dual system audio to 99.9 percent solves the sync problem with the 5D.The solution is to change the speed of the audio not recorded on the 5D to 99.9%. Once you do this your audio will stay locked in sync for the duration of the clip.

At this point we are in sync and could start editing. However, for big projects and especially multi-cam projects I prefer to "bake in" the audio. Doing this, to me, is safer and keeps things better organized. Doing this renders the audio speed change into new synced master clips that I bring back into Final Cut Pro to start editing. This ensures that the audio and video will stay locked together throughout the post process.

Step 4 - Setup Audio Outputs

Adjust the audio outputs to 4 if you want to keep both audio sources.If you want to keep the on camera audio in addition to the dual system audio you will need to adjust your sequence settings before exporting. Open sequence settings and go to the audio outputs tab. By default you will have 2 audio outputs, increase the audio outputs to 4. This will keeps track A1 & A2 separate from tracks A3 & A4 in the new mater clips. If you do not do this you will mix both the camera audio and dual system audio together into 1 stereo pair. If you do not need the camera audio make sure you disable or delete those tracks before exporting.

Step 5 - Batch Export

There is a window in Final Cut Pro that I have never really had a good use for until now. The Export Queue.

The Export Queue allows you to batch export sequences. This is why I create a separate sequence for each clip. Drag all of the sequences into the export queue and confirm your settings are set to export same as source, select where to save the new master clips and click Export. 

Use the Export Queue to batch export and create new master clips.Final Cut will create new master clips, rendering the audio at 99.9% and baking it into the new quicktime files. The new master clips will contain 4 audio tracks if you decided to keep the camera audio. Once the export queue has finished creating the new master clips we are ready to start editing the project.

This may seem like a lot of extra steps but the process actually goes really fast once you get the workflow down. It is worth taking the time to get the project setup properly before you start editing.

Update on Thursday, March 25, 2010 at 5:58PM by Donald Kilgore

With the latest Canon 5D Mark II firmware update 2.0.3 (now 2.0.4) the camera will now record in proper frame rates that do not require changing the audio speed to 99.9%. This update not only adds the huge update of being able to record 24p but also records all frame rates to NTSC broadcast specs as well as PAL, solving the drifting audio sync problem. 

Canon 5D Mark II Frame Rates - Firmware 2.0.4

NTSC:

• 1920×1080 : 30 fps (changed - actual 29.97 fps)
• 1920×1080 : 24 fps (added - actual 23.976 fps)
• 640×480 : 30 fps (changed - actual 29.97 fps)

PAL:

• 1920×1080 : 25 fps (added - actual 25.0 fps)
• 1920×1080 : 24 fps (added - actual 23.976 fps)
• 640×480 : 25 fps (added - actual 25.0 fps)

Audio and the Canon 5D Mark II

One of the biggest limitations of the Canon 5D Mark II is its ability to capture great audio. The 5D2 captures beautiful pictures, but its ability to capture audio is severely limited. With the built in microphone not only is the sound quality poor, but it also picks up all sorts of noise from the camera mechanisms and operator handling. The built in mic should be your last resort. If you can, invest and take the time to ensure your picture's sound quality matches that video quality.

"You may have a great picture, but if your sound isn’t very good, audiences will quickly become annoyed and either emotionally or literally abandon your film. That’s never a good thing.” -MIKEL J. WISLER

Having good audio is more important than having a good picture. If your content is good, picture quality is forgivable but if the audio quality is poor, it is very difficult to tolerate. So if we are going to shoot anything besides silent b-roll we are going to need an audio solution to compliment the 5D2.

I have reviewed and tested various options for capturing audio with the 5D2. This is what I have found to be the best audio solutions for the Canon 5D Mark II.

Using the stereo 3.5mm input

The 5D2 does have a 3.5mm audio input so it is possible to add an external microphone. An external microphone offers a huge improvement over the camera's built in microphone. There are a few "all-in-one" microphones on the market that mount to the camera's shoe and plug into the 3.5mm input. Check out B&H's review complete with audio samples.

One popular option is the Sennheiser MKE400. I have read reports of people experiencing considerable amounts of hiss from the Sennheiser MKE400. Additionally, the MKE400 is a mono mic.

I'm using an old school flash bracket to mount the Rode Stereo VideoMic above the camera.

I found the better option to be the Rode Stereo VideoMic. Not only is the Rode a better performer it also captures stereo sound taking advantage of the 5D2's stereo input. This works great for capturing ambient sounds and reference audio.

The Rode is not going to be the end all solution, for capturing dialogue and critical sound we are going to need something else.

You could use the BeachTek DXA-5D or the juicedLink CX231 and add XLR inputs to the 5D2. Both of these units mount under the camera, have two XLRs inputs, phantom power, and gain controls. In some situations this could be a good solution, but it is limited. You still will not have control over the camera's input levels. Even with the Magic Lantern hack your audio quality will ultimately suffer and be limited to the camera's ability to only record 16-bit/44.1kHz Linear PCM audio.

Dual system audio

The H4n has a standard screw mount on the back. I'm using the arm from my litepanel to mount the H4n to the camera's shoe.The only solution to getting great audio with the 5D is to record it separate. Just like shooting on film, we need to slate it and sync in post. It is a few extra steps and a bit of a headache if you are used to diving straight into editing, but the results are worth the extra time.

I started researching various field recorders like the Tascam HD-P2, Roland R-44, and top of the line Sound Devices 702T. These were all excellent field recorders, but in the end it was the much cheaper Samson H4n Zoom that I found to be the best option.

Not only was the H4n a fraction of the cost of these other recorders but it was also smaller and could easily mount to the camera. The Zoom H4n records WAV audio files with sample rates from 44.1kHz/16bit to 96kHz/24bit, has phantom power, and a headphone jack for monitoring. The best thing about the H4n is it has the ability to simultaneously record up to four channels, the 2 internal microphones and 2 external inputs. This is great because you can capture ambient environment sounds with the built in microphones while using the external inputs for dialogue. If recording outside, pickup a "red head" for the H4n's internal microphones.

Zoom H4n Windscreen For Your Handheld Recorder with the Canon 5D Mark II and Joby Gorilla pod from iamkalaniprince on Vimeo.

Putting it all together

Once you have successfully captured your audio, you will need to sync it in post. There are a few tricks with the 5D2. I will post a separate blog on the post process soon.