Tips for Using the Zoom H4n in a DSLR Video Shoot
Video-enabled DSLR cameras have become the Tickle Me Elmo's of the creative production world, but one thing Elmo isn't laughing at is the audio quality of the built-in microphones. Whether your camera has a microphone input or not, you should consider using an external digital audio recorder to handle the sound recording for your next video production. Using an external audio recorder in video production and filmmaking is often referred to as "double system." This practice requires a bit more work on your part; but if the ultimate goal is to create an excellent finished product, then capturing good sound should be a top priority.
The extra work you'll be required to do extends to every phase of production. In pre-production you're going to need to plan your audio recorder/DSLR operation workflow. During the actual production you're going to have to operate (or preferably have someone else operate) the digital audio recorder. In post you're going to need to transfer the sound files into your computer and sync them with the picture. There are many inexpensive yet high-quality portable audio recorders on the market that will enable you to do all of this, but a favorite among video producers and independent filmmakers is the Zoom H4n. Not only does the H4n offer one of the best bang-for-the-buck ratios out there, but more importantly, a large number of video-enabled DSLR users have adopted this specific recorder for use in video production and are achieving impressive results.
|The Zoom H4n is a popular audio recorder among DSLR video shooters
The Zoom H4n is a bit of a Swiss Army Knife production tool. Not only can it serve as an external recorder for DSLR video work, it can also act as an audio interface for your computer. This means that you can connect it to a Mac or Windows PC via USB 2.0, plug a microphone into one of its two XLR inputs, and use the H4n to create voiceovers in post production. You can record directly into the timeline of Final Cut Pro, or into any video or audio production software that supports external interfaces. There are also lots of powerful features for musicians in the H4n, such as multi-track recording, a guitar tuner, and a metronome. It's even possible to record four separate channels of audio using the H4n's high-quality built-in stereo condenser microphones and its two XLR microphone inputs simultaneously.
You can easily set the H4n to record different file formats and audio resolutions--including the ability to record audio as compressed MP3 files. But since the goal here is to achieve the best quality possible, let's forget I even mentioned the name MP3! In my personal experience recording sound for video productions, I've had great results setting the recorder for 24-bit/48 kHz WAV files. Many people have reported excellent sync results when setting the Zoom H4n to record sound with 16-bit/48 kHz WAV files for shooting 24p video. But I would recommend trying 24-bit/48 kHz first. It's a richer-sounding bit depth, and it gives your audio recordings more headroom.
|The Zoom H4n and a few close friends
Because there are so many video-enabled DSLR's that offer different frame rate capabilities, you may need to experiment to find settings that work best between your camera, audio recorder, and editing software. I strongly recommend doing test shots to work out any issues before you get involved with a serious production. From start to finish, roll your camera and external audio recorder for over 10 minutes. As the equipment runs, periodically clap your hands in the frame (or better yet, use a clapper slate). After you've logged the footage into your computer, if the claps stay in sync when you watch the test video, then you've successfully recorded double system sound. If the clapping audio isn't in sync with the clapping on screen (especially later in the footage, 5 or 10 minutes in), then you need to adjust the settings of your software.
Interestingly, sync issues happen more often when the video editing software's preference settings are incorrect. The audio and video files are usually not at fault. A common pitfall is when the timeline of the video editing software is set to a different frame rate than the video and audio footage. Even if the DSLR was set to record video at 24fps and the audio files were recorded as 24-bit 48 kHz (or 16-bit 48 kHz) WAVs, if the timeline in the software is locked to 29.97 frames per second, you're bound to have sync issues.
How you approach using the Zoom H4n with your DSLR can vary. If you're shooting everything by yourself, keep in mind that you're going to have to hit record on the H4n every time you start recording on your camera. You will have another set of batteries (the H4n runs on two AA's) and another memory card to keep tabs on as you work (the H4n records onto SD cards). Microphone placement also becomes a big issue if you're shooting solo. If the microphones are not physically close to the sound source, it's going to sound that way. I don't mean to discourage anyone from shooting double system while working alone, but you do need to keep these factors in mind.
One nice touch is that the Zoom H4n can be mounted on top of a DSLR camera. The H4n features a 1/4-20 tripod mount on the back of its chassis. With a simple accessory like the Pearstone Male Accessory Shoe, the Zoom H4n will balance comfortably on the shoe of your DSLR. However, you'll have to keep handling and wind noise in mind if you're going to be moving around with the H4n hard-mounted on your camera. If you want to get into using external professional microphones with the H4n, you could rig up your DSLR with shoe-extension accessories like the NRG 59111 Accessory Tri-Mount. This would enable you to mount the Zoom H4n and a shotgun microphone with a shockmount. For more options on microphone shockmounts for a DSLR camera, check out this B&H Insights blog post.
Whenever possible, try to work with a professional location sound person. They will take the burden of capturing the best sound off of your shoulders, allowing you to concentrate fully on making the best-looking picture possible. The more people you can get to help out on your production, the better. As mentioned earlier, it's a good idea to bring along a clapper slate whenever you shoot double system. Have a production assistant (or a friend who owes you a favor) operate the slate at the beginning of every take, and at the end of the take, too (if it's a lengthy shot). This will really help you sync the footage in post.
Feel free to get creative with the Zoom H4n on your shoots. If you don't have external microphones, have your talent hold the H4n just below the frame when they're speaking to the camera. This way if the microphones are closer to the subject's voice, it will likely sound better than if the H4n was mounted on top of your camera. If you don't have wireless microphones, you can plug a XLR wired lavalier or a mini-plug lavalier directly into the H4n and conceal the recorder in the talent's pocket for a wide shot. Finally, don't be intimidated by people who tell you that you can't achieve good audio with a limited budget. Let your own research and experimentation determine what you can and can't do. The clock is ticking. Stop dreaming about making a film. Get out there and bring your vision to life. Elmo is rooting for you!