DSLR Audio Questions

[Foster Kane]

I plan on doing interviews with my DSLR and I was wondering what has everyone's experiences have been like with the audio.

1.What type of external mic do you recommend? I have a Rodevideomic for my Canon HF 200. Will I need a cold shoe adapter?

2. I have seen DSLR shoots where there is a man with a boom mic. Is that necessary?

3. What problems should I expect?

4. The T3i has manual audio, how important is that?


Thank you everyone.

 

[M. Gilden]

OK- I'm THIS close to just writing up an audio bible for these cameras and asking for it be stickied. There's a ton of information, and honestly its not very easy to find.... So there are questions like this far too often.

In a nutshell, the general belief is that you just can't use the audio in camera for anything. They were designed to take great pictures, audio was an afterthought clearly. This is for two reasons: All the Canon DSLRs audio in camera used automatic gain control (more on that in a minute), and has weak pre-amps.

So, you'll find a lot of people here telling you that you MUST get an external audio recorder if you want anything decent, and then sync the audio track in post. Thankfully, that's not entirely true anymore, but it is still good advice and often the easiest answer if you don't mind the extra steps to sync.

Thankfully, manual gain control is being offered on Canon's newer models. Why is this important?

Auto Gain a nice idea for consumer type point-and-shoot cameras. But the big problem when trying to make a professional sounding shot is that the volume will be constantly changing, bringing static and hiss in between dialog. Unacceptable. Canon didn't give us an option to turn that off, so it was a no brainer to go external- the internal audio on these cameras was simply NOT USABLE at all.

But, now that you can turn that off, and set the values manually (either with a new camera or using the Magic Lantern hack), you're left with just the preamps to deal with.

Are the pre-amps that bad?

Well, depends on what you are doing. If you are recording a narrative, or need to set the tone with a lot of dynamic range sound, your best bet will be the lower noise floor of an external recorder. Better yet, get a pro audio engineer with their own boom pole and let the camera man just focus on the shot (that's the way pros do it, and why you see that alot).

But, if you are just recording a run-and-gun style interview, maybe even with a wireless lav mic, you are going to notice very little difference in using an external recorder, and it probably would not be worth the extra investment and work to sync.
Wireless lavs work well because the receiver actually has its own mini preamp that can feed a slightly hot line into the camera. A straight up mic without any amplification might not work as well, leaving the sound quieter and closer to the noise floor. But, I've seen people use it on cameras with the AGC disabled and it was usable for their purposes.


That should be all you need to know for now.

 

[Chris Santucci]

1.What type of external mic do you recommend? I have a Rodevideomic for my Canon HF 200. Will I need a cold shoe adapter?

That mic is great. I use on on my 7D. It attaches to the hot shoe on the 7D or 5DMKII.

2. I have seen DSLR shoots where there is a man with a boom mic. Is that necessary?

That depends on how good you want the audio to be and how close you can get your camera to the sound hole of your subjects. The closer you can get a mic to the action, the better. If you need to hear what people are saying in a room full of noise, get the mic as close as possible to the person speaking, preferably with the noise *behind* you.

3. What problems should I expect?

If you use AGC with an on camera mic, you will have a bit of background noise evident, but again, as long as you're close enough to the sound you want to hear, you can get acceptable audio which you can then filter as needed in post.

4. The T3i has manual audio, how important is that?

It's important if you are shooting in a controlled situation like a sit down interview where you can LOOK at the audio level meter on the camera and adjust it before rolling in order to get a nice steady level, instead of having levels that raise and drop as in the case of AGC.

 

[davefisk]

Avoid automatic gain control at all costs. I have done audio for tons of sit down interviews, and I use a hardwired lav as well as a boom on a stand. I'll have the lav on one audio channel and the boom on the other. You can run that into a two channel mixer (like the sound devices mix pre), and then come line out into the camera. I would record a scratch track of audio on the camera, and then run a separate audio recorder, and use a clap slate to sync it in post.

The short answer is to hire a sound person. A sound person can be expensive, but not hiring one can cost you more in the long run.

 

[iHartVideo]

Regardless of manual gain (which, BTW, the GH2 has) the onboard mics just pic up way too much room/ambient sound. Everything is way to 'reverby' and room like.

I did some interviews this weekend and bought a wireless lav system... the sound much more professional and sounds fantastic compared to any onboard/on-rig solution.

 

[aguia]

I'd like to hear from anyone what they are using as a high-end double system with an HDSLR. Time code please?