Videomaker – Learn video production and editing, camera reviews › Forums › Technique › Sound › Why use a external recorder?
August 2, 2014 at 9:56 AM #80486CyreousMediaParticipant
I've read so many times that even though your DSLR may have an input jack for audio do NOT use it, instead get yourself an external recorder (i.e. the Zoom H4n, if 'external recorder' isn't the correct term now you know what I'm referring to) and plug your mic into that. I don't have enough gear yet to try it out so would someone please explain to me what difference it makes? If I have a Rode Videomic Pro attached to the end of a boompole and plugged into an H4n it, in my mind, would sound the same as having a Videomic Pro attached to my DSLR's hotshoe and recording that way. The only exception would be how close you could get the mic because on the camera it's a slave to the visual perspective; wherever the camera has a good shot is where it will be and the mic will have to put up with it.
If anyone could shed some light on this I'd appreciate it, whether a technical answer or a simple one I don't care, it's just driving me crazy and I don't want to drop $100+ on unncessary gear.
Thanks in advance
August 4, 2014 at 3:08 PM #210869mcrockettMember
It's not really a rule of thumb that you MUST use an external recorder. In many cases, recording audio directly to your camera using an external microphone connected to the camera can be OK as well. But there are some things to consider.
For one, you mentioned it in your post that camera position can be part of the reason. Using an external recording device, you can get the microphone closer to your subject for clearer, cleaner audio.
Also, a lot of cameras, although they may have an input for an external microphone, may not have any way to visually monitor the audio levels. Even if you have a jack to plug in a pair of headphones to listen to your audio, it's not the same, especially if your camera has the ability to control the volume of the sound going out to those headphones. In other words, what you hear in the headphones may not necessarily be what is being recorded to the video. Most external audio recorders will be able to give you a visual representation of your audio levels so that you can see if the signal is too low, or if it may be peaking too high.
Another reason may be that you would want to use your audio recorder to record vocals, while you use the in-camera audio to record ambient sound. This, of course would depend on what it is that you're shooting.
I'm sure that there may be other reasons that other videographers would give, but those would be my reasons. Hope this helps.
August 4, 2014 at 3:51 PM #210872Eric MatyasParticipant
One other thing to consider is: if you're recording dialogue with an external recording device rather than into your camera, you'll need to slate in order to ensure lip sync in post. This generally means needing another person on your crew.
August 4, 2014 at 8:14 PM #210878brunerwwMember
The principal reason not to record directly to your camera is the generally poor quality of in-camera preamplifiers or "preamps".
Whether your microphone is on the camera or off, the noise contribution of the crummy preamps in most DSLRs (even those with manual gain control) is apparent in quiet scenes.
The H4n has marginally better preamps than a DSLR (still noisy by professional standards), the JuicedLink preamps are quieter than the H4n and the preamps in the professional quality $2000 Sound Devices 702 field recorder are quietest of all.
Here's a great explanation/comparison from Robert at JuicedLink:
Hope this is helpful!
August 7, 2014 at 9:56 AM #210893CyreousMediaParticipant
That was all very helpful and interesting. I do suppose I need to do some research on the science behind sound and how it's recorded; many of the numbers in the video were new to me so I didn't fully understand the clip with my head although I did hear the difference.
I appreciate the help
October 13, 2014 at 3:36 PM #211229GMHorseParticipant
I think audio consideration is critical to video and there are very good reasons to employ an external recorder for your audio instead of the audio in the camera. Firstly, there are compromises to the audio recording in cameras, most notibly AGC (automatic gain control) and compression. You usually have the ability to turn these on or off, but you actually do want some mild compression when recording and there just isn't the level of control in most cameras that you'll need. Also, the gain circuitry in cameras will never be as clean as those in a good, dedicated recorder. I use a Denon portable solid state recorder and before I take a shot I walk into the shot and clap my hands – that way when I line up my audio and video on the timeline of my editing software I can line up the audio and video perfectly, link them together and then my audio is perfectly synced for the shot(s) I am editing. If you care about audio, you'll get better dynamic range, lower noise and better quality audio with a dedicated recorder. My 2 cents.
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