iPhone Videography – Part 2: Audio

As mentioned in the preceding post in this series, this post is in response to my own investigations and advice others have asked of me.

Background
The iPhone provides the opportunity to have a HD Video Camera on hand where ever we go. But can a phone really replace a dedicated video camera. We currently use a Canon HV20 tape based HD camera in our department. The camera has been augmented with a wide-angle lens, a directional microphone and tripod. Ideally we’d also have lights too. The iPhone is certainly more portable and convenient and it doesn’t require the video to be converted from tape in order to edit it (you can even do basic editing and upload to YouTube from the phone). But is it possible to ensure similar quality video on the iPhone?

The key considerations to quality video are the image (including resolution, composition and lighting) previous post (Part 1), the sound (this post) and stability (Part 3).
Sound
It is said that despite video appearing to be primarily a visual medium, you can get away with poor image quality, but you can’t get away with poor audio quality. The built in microphone on the iPhone (in common with many built in microphones) provides a poor quality experience that can be significantly improved relatively easily. The key thing to understand about recording audio is that our brains are very good at focusing in on important sounds in our environment (cocktail party effect), but technology isn’t so intelligent, so we have to help it. The way we help it is by providing the focus that our brains do naturally – the equipment doesn’t know that you don’t want to capture the sound of that air conditioning, computer fan, strip light hum or if shooting outdoors traffic and aircraft (all things we don’t normally notice).

So there are 3 keys to capturing good audio:
Equipment: Different mics pick up sound in different ways and it could be a huge subject in its own right. To keep things simple though you probably just want to consider either a shotgun mic (also known as hyper cardioid) or a lavalier mic. A shotgun mic is highly directional and this video illustrates how to use one to get clean focused sound http://www.youtube.com/watch?v=smQf9W1tx5A on the other hand a lavalier mic despite being omni direction provides focus by being very close to the sound source. This clip gives you an idea of what audio gets picked up by different mics (built in, lavalier, shotgun and condenser) http://www.youtube.com/watch?v=0-TB9lAUguc
A couple of other options I should mention are wireless and boundary mics. Due to recent changes in UK law I won’t get in to wireless mics except to say that Sony have an interesting Bluetooth offering that may be a handy extra to have in your kit bag (see below). As for boundary mics: I recently had to video a seminar and borrowed a boundary mic and amplifier and was pleasantly surprised by the results – picking up both the speakers and the audience questions.

Placement: Hopefully the clips above will have already illustrated the importance of placement! One thing to add is that using a shotgun mic adds some extra considerations not mentioned above. If it’s camera mounted (not a good idea anyway) and you’re shooting wide angle then obviously it can get in the shot. So if you’re using it in it’s best configuration, on a boom, you’ll need an extra pair of hands to hold the boom. Finally, whether on camera or on a boom, if your subject moves around a lot, it’s going to be tough to pickup a consistent sound levels!

Monitoring: Hearing exactly what the equipment is recording is really important. Hopefully that was illustrated in the first shotgun clip above (with the lawn mower). There are two components to monitoring: levels and headphones. Levels isn’t something you get much opportunity to monitor or adjust when shooting video on the iPhone, but some accessories do allow you to adjust the ‘gain’ (see below). Headphones also present a little bit of a problem on the iPhone. Not all recording software allows you to monitor the audio while using an external mic and in some circumstances where you can monitor the audio there’s a danger of ‘latency’ (that’s where the audio coming out of the headphones is a fraction of a second behind the audio going in to the mic), which can obviously be really hard to listen to! There’s more detail relating to these issues below with each item, but the key thing is that you want to hear whether you video recording is ‘paying too much attention’ to that lawnmower etc!!

So what appear to be the options?

Unfortunately I don’t have the resources to test the options, so I’ve been digging around the interweb to see what others are using and what they’re saying. If you have anything to add or any corrections you think I should make, please let me know. In the mean time here’s what I’ve found so far.

Microphones

Most mics will need an adapter for the iPhones 4pin headphone socket. There is lots of information about adapter cables for iPhones here http://www.kvconnection.com

Startech.com 3.5mm 4 Pin to 2x 3 Pin 3.5mm Headset Splitter Adapter £5.40
http://www.amazon.co.uk/dp/B004SP0WAQ
Use to make most mics compatible with the iPhone’s type of audio jack.

Audio Technica ATR-3350 ATR Series Omnidirectional Condenser Lavalier Microphone £27.55
http://www.amazon.co.uk/dp/B002HJ9PTO
This mic seems to come up as a recommendation again and again, but beware of the need to have spare batteries. This is a useful review of what you get http://www.youtube.com/watch?v=bR5RoJAy52Q (Needs a 4 pin adapter – see above.)

Audio Technica ATR-6550 ATR Series Condenser Shotgun Microphone £69.00
http://www.amazon.co.uk/dp/B002GYPS3M
This video includes comparisons of how the ATR-6550 sounds in different configurations http://www.youtube.com/watch?v=SCmQDF6kEiI It seems to be cheap and cheerful and will probably need some post processing to get rid of noise. (Needs a 4 pin adapter – see above.)

MicW i825 kit – Omni lavalier mic & accessory kit £131.99
http://www.amazon.co.uk/dp/B0081SZMI8
Lavalier mic specifically developed for iPhone http://www.mic-w.com/product.php?id=1 includes an adapter for monitoring audio with headphones – something that usually requires software when using the headphone socket to record audio on iPhone.

MicW iShotgun Kit £191.00
http://www.amazon.co.uk/dp/B009AXPUDA
Again specifically developed for iPhone. Nice review here http://www.youtube.com/watch?v=c8tc9OXryk8 Manufacturer’s site here http://www.mic-w.com/product.php?id=77

RODE VideoMic Pro Compact Directional On-Camera Microphone £149.00
http://www.amazon.co.uk/dp/B004K8WPUQ
We already have one of these for for our Canon HV20 and the audio is fine. Once I get the 4 pin adapter I’ll try it with the iPhone too.
(Needs a 4 pin adapter – see above.)

Samson Meteor USB Microphone £56.54
http://www.amazon.co.uk/dp/B004MF39YS
Compatible with iPhone/iPad via Apple’s USB connector, at least has its own built in headphone socket for monitoring audio http://www.samsontech.com/samson/products/microphones/usb-microphones/meteormic/
See a review here http://www.youtube.com/watch?v=bOOZRRSp-6Y Seems quite restrictive in that you need to be around 10″ from audio source, so probably best for audio interviews and podcasting.

Apogee MiC Studio quality microphone for iPad, iPhone, and Mac £152.10
http://www.amazon.co.uk/dp/B006W11TT2
http://www.apogeedigital.com/products/mic.php
http://www.youtube.com/watch?v=EHUrnQNudVQ
http://www.youtube.com/watch?v=K6XAp2_dN5A
Digital connection + gain control + needs Apple 30pin adapter for use with iPhone 5 – can monitor audio via iPhone headphone socket, but you’re likely to get latency + also has a longer cable as an optional extra. Probably best for audio interviews and podcasting.

Fostex AR-4i Audio Interface for iPhone £49.00
http://www.amazon.co.uk/dp/B005CNDYTY
http://www.fostexinternational.com/docs/products/AR-4i.shtml
Comes with its own microphones, audio gain and headphone monitor, but would benefit from the addition of a shotgun mic or a lavalier mic (where the gain may compensate for the quietness that some have commented on with the ATR-3350) or both – see above. It also has tripod mounts and cold shoe built in. Not clear if it is compatible with Olloclip. Though originally designed for iPhone 4 (via 30 pin socket), it now comes with an iPhone 5 adapter (you may want to make sure that you’re buying from current stock). Also note, this seems to be the only stereo mic here.

Fostex Audio Retriever AR101 – so new that not yet available in UK ($199 in US from BHPhotoVideo )
http://www.fostexinternational.com/docs/products/AR101.shtml
https://www.youtube.com/watch?v=TACxvKY-z10
This seems to be an improvement on the AR-4i since it is no longer a case that the phone slots in to. This means the audio now goes in via a 30 pin cable and you can use the Apple 30pin to lightning connector for iPhone 5. It can also be used as audio input for an SLR or to a PC/Mac via USB.

Sony ECM-AW3 Bluetooth Wireless Mic £139.94
http://www.amazon.co.uk/dp/B002DUCRXS
http://www.sony.co.uk/product/cac-microphones/ecm-aw3
Look like an interesting option for a wireless mic – checkout this review to get an idea http://www.youtube.com/watch?v=rV9wLcvgxjM
(Probably needs a 4 pin adapter – see above.)

Art Tube MP Original – Valve Mic Preamp With 48V Phantom Power £38.94
http://www.amazon.co.uk/dp/B0002GZZNY
This is what I used with the boundary mic, unfortunately I’m not sure who made the the mic, but the Tube MP offered in expensive amplification which is why I mention it.

Conclusion

Microphones: While I’m intrigued by the offerings from Mic-W and would like to hear from anyone who’s tested these, I think for my purposes the ATR-3350 will be the most flexible (and affordable), but I’ll keep a close eye on the audio levels in use. This mic also strikes me as one that will be useful to have in my kit bag no matter what direction I go in for later purchases. I’ll also be seeing what I can do about monitoring and seeing if the Mic-W adaptor accessory will enable me to monitor this mic. In future I can imagine going down the Fostex AR101 route which looks like it will provide both a high level of control and good flexibility (I’ll still be able to use the ATR-3350 with it).

The next thing I’ll look at is stabilisation – you can read that in Part 3 and if you haven’t already seen it, you can see what I said about image in Part 1.

I hope this is of use to some of you – I sure wish there had been something like this for me to go to in the first place. 😉

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