MP4 vs. AVCHD for the Canon C100 Mark II

The Canon C100 Mark II, like most higher-end cameras these days, is capable of shooting in a few different codecs. But where most manufacturers would offer a few distinct flavors - a RAW option and a compressed option or an 8-bit and a 10-bit codec, for example, Canon has included two confusingly similar options - MP4 and AVCHD. So when should you use each of them?

Use AVCHD if Audio is a Priority

The audio in the AVCHD codec is recorded in a lossless audio format - Linear PCM. Think of it as the audio equivalent of shooting RAW - you have a lot more room to push it in post, and the inherent quality is much higher because you are keeping every ounce of information. 

MP4, on the other hand, is compressing it all into AAC format, best known as the codec of choice for iTunes.  Non-audiophiles probably can’t tell the difference, and for web-exclusive content the difference is probably negligible. But the quality loss is real, and if that concerns you then MP4 is probably not the right codec choice.

Use MP4 if Bit Rate is Your Top Priority

Canon’s MP4 implementation on the C100 Mark II is capable of stepping up to 35mbps, as compared to AVCHD’s upper limit of 28mbps. We can only speculate as to why exactly that is, but if squeezing the highest quality image out of this camera is your top priority, then shoot in MP4.

Use AVCHD if You Want Slow Motion with Audio

If you want to record slow motion in AVCHD, your bit rate has to be set at 24mbps. Then you simply toggle down to frame rates and select 59.94. Shoot your footage as you normally would, but know that when you bring the footage into your editing software you will have to manually slow it down to 40%. Shooting your slow motion in AVCHD will record audio /and/ video, unlike in MP4.

Use MP4 if You Want Easily Accessible Slow Motion

To shoot slow motion in MP4, your bit rate has to be set at either 24 or 17 mbps and your frame rate has to be set to 23.97. Then, under “special recordings” in the other functions menu, you turn on Slow and Fast motion. The C100 Mark II will now shoot at 60fps but play back at 24fps, essentially conforming the clip in-camera. This is easier to toggle in and out of quickly as it is assignable to a custom function, but note that the C100 Mark II will not record audio at all when in Slow and Fast mode. 

In Conclusion

The dirty secret is that while there are a few subtle differences that differentiate these two codecs, you will get roughly the same image quality regardless of your codec choice. Hopefully this article has given you a couple features to judge these codecs on, but it would be hard to go wrong with either.