No, this post isn’t about the delusional Cthulu horror film that Sam wants us to film, or the romantic comedy about the giant squid that escapes London Aquarium to find Friendship and True Love.
You’re surprised, I can tell – we don’t usually blog much and, and we certainly don’t do kit reviews over here at Tortoisebutler, so imagine my surprise at finding myself sitting here writing a kit review. That said, when the Tentacle Sync project currently raising funding over at Indigogo the device looked a too good to be true and we just had to give it a go.
The device is a very small, very simple time code generator which weighs about 30g.
Here’s a photo of one.
Cute isn’t it? It is formed from lightweight plastic and the bottom will stick to velcro or felt (discovered after putting it down on a felt sofa and encountering resistance on removal)
Imagine two secret agent’s synchronising watches at the beginning of a mission. This is the basis of what Tentacle Sync is and does.
We thought of lots of use cases for the Tentacles but the most likely scenario is going to be something like this:
You have a DSLR and you like making films. You’ve stopped using the camera’s on-board microphone for your films because frankly the sound quality lets down your beautiful beautiful pictures. You’ve bought an external recorder and (if you’re lucky) you’ve convinced someone to operate a boom mic for you – or you’ve put the recorder in your actor/interviewee’s pocket and plugged a wired tie-clip mic into it.
Or you’ve found someone to handle even more complicated microphone setups for you!
(Don’t ever do this one by the way, the second anything gets disconnected you’re stuffed)
Now you have great sound to match your wonderful images, but you’ve got to sync the damn recordings up. After going cross-eyed trying to line up the clean sound to the crap camera sound (and therefore the video), you buy a clapperboard and clap at the start of each shot (clapping your hands mostly works but feels cheap and tawdry). The clapperboard makes you feel like a proper filmmaker and it makes a neat vertical line in your audio waveform which you can use to match up the clean sound against the crappy camera sound. You discover software like Dual-Eyes and Plural-Eyes which even automates the process of lining up the audio for you. For a time everything is wonderful.
Then, as you shoot more and more, cracks start to appear in the relationship. Occasionally the software inexplicably fails you (the background noise is too high, there are other confusing sounds going on, the planets are unaligned, who knows). Sometimes you have to deliver the files to an editor in a hurry and they don’t have sync software or the time to do it manually. Sometimes your clapperboard person freezes almost solid in a midnight shoot by a canal which we absolutely had permission for, their hands chattering like teeth, the staccato rhythm of the clapperboard now confusing as all hell and sheer humanity causes you to send them to the pub to thaw out – at which point any remaining defrosted member of the crew now has another job to take on. Sometimes you are filming a soulful confession between a has-been magician and their loyal rabbit and the clapperboard freaks the magician out. Or the rabbit, whichever. You get my point. Clapperboards are great, but wouldn’t it be lovely if we didn’t always need them?
In my day job I shoot sensible things with sensible cameras that have timecode generators built in. These cameras always know what time they think it is and they can be synced to each other – our audio recorders can use (relatively) expensive add-on timecode boxes, so everything is operating on the same clock. Since devices are synced up before shooting, the resulting recordings don’t have to be painfully synced up afterwards. More often I just plug a high quality microphone into a professional camera, (which has all the inputs to allow me to do that) and I don’t even have to worry about the clean audio being separate from the good video.
In everything other than my day job I shoot sound separately because I film with impossibly small micro four-thirds cameras, DSLRs, go-pros, beautiful modern kit with needlessly complicated lens systems involving Dad’s old glass, Ebay adapters, soviet lenses, cheap and ill-advised wide-angle converters, sunset filters and vaseline… I like being able to play with lenses, I like being able to run about with lightweight kit and the kinds of video cameras that suit this sort of messing around are a lot cheaper than the ones I use at work and do not come with timecode generators.
Back to the tentacles then.
When I read about Tentacle Sync over at it’s indigogo page, I imagined two tiny squid with digital wrist watches which they synchronised at the beginning of the shoot, one squid sitting on the camera with a tentacle plugged into the microphone port, and the other squid wrapped around the sound recorder with a tentacle plugged into a spare microphone channel. These two cute creatures would helpfully feed the correct timecode into the camera and the sound recorder, and needed to be fed occasionally only on electricity.
Reality so often disappoints, but in this case I found I wasn’t actually too far off the mark. When the test units arrived in an impossibly light parcel from Germany, I found myself holding two tiny boxes (tentacles!) and a pile of leads. While charging both tentacles up via their micro USB ports, I leafed through the manual. Synchronising the clocks on the devices is straightforward. Plug the devices into your computer, set the time and the frame rate of your project using the supplied app (the units can currently handle 24, 25, 30FPS and will – I am assured – be able to do 50 and 60FPS at time of shipping). Now turn unit A on in ‘Master’ mode (long press of the ‘on’ button so that the LED lights up green) and unit B on in ‘Slave’ mode (short press of the ‘on’ button so the LED lights up red). Plug the two units together using a dual-ended 3.5mm audio cable and after a moment both units show green LEDs. That’s it – you’ve jam-synced the devices together, the clocks are synchronised, you are good to go.
One tentacle was plugged into the 3.5mm mic input of a Panasonic GH3 camera (it was so light I could actually secure it in place with washi tape) and the other unit into the 3.5mm mic input of a Zoom H4N audio recorder set to 4-channel mode.
Since the tentacles produce audio timecode, any attempt to monitor sound on headphones at this point leaves you with to what sounds like the chattering of friendly but excitable aliens all over your audio. The correct thing to do (for the Zoom audio recorder) is to set the levels for the alien chattering to be loud, but not clipping, and then to mute that channel completely. You can now monitor and adjust the sound of your actor on your other channel(s) as normal.
This done, we set out with our actor to film something. We wanted to be thorough so we filmed in a variety of places – a quiet railway bridge which occasionally had a train going under it/a busy road with loud traffic and wind in the background – and did things like
- turning the camera and audio recorder on at the same time
- turning the camera on at the start and the audio recorder on mid-shot
- turning the audio recorder on, recording sound and then turning the camera on and off throughout
in an effort to try out the most likely scenarios.
Once the files from both devices were dumped to a computer (in this case a Mac running Mavericks), the Tentacle Sync, Sync software was fired up and the files imported in. Something unexpected happened at this point – instead of getting the expected neat list of which audio files matched up to which video files, we saw all our recordings correctly laid out on a timeline. It was clear what portions of audio had corresponding video and vice-versa.
It was possible to play back the timeline and see if the syncing had happened correctly (it had) and even better, it was possible to export the timeline as files that could be imported into an editing programme to recreate the timeline there. Lastly we exported the all the clips as Prores video files with the synced clean audio only.
Here’s my favourite clip from the shoot – apparently if you ask an actor to monologue ‘anything you like‘, this is what happens.
This is the file exported from the Tentacle Sync software, converted to an MP4 and uploaded to Vimeo, it’s had nothing else done to it, as you can hear, even with a very directional boom mic, the traffic is loud enough to be audible. I’m pretty cheered by the fact that we weren’t able to freak the alignment software out at all.
So would I use this device again? Actually I’d jump at the chance, especially if I was shooting on my own, just to be able to lose the faff of having to use a clapperboard.
My favourite thing about the tentacle units is just how quick and easy it is to jam sync them together. The software is extremely pleasant to use and the units themselves are very light and unobtrusive. I was holding them onto the camera with Washi tape, which hardly supports any weight at all. As a solution, at the indigogo prices, they are more expensive than a clapperboard and less expensive than everything else you can currently buy – to my knowledge at least.
A final few points
- The tentacle units maintain their sync for 24 hours before needing re-jamming, and the battery lasts for 40 hours
- There is apparently an on-board mic you can use to capture camera reference sound (although I didn’t test this)
- These units aren’t exactly new technology – we’ve had timecode generators for years – but they are cheap and I do like the software
- The sync software at the moment exports video cropped to the start of the video, not the start of the audio. In an ideal world I’d like to have it export files starting with either audio or video (whichever happens first) and have black video frames over any audio that has no corresponding video. But then I have a habit of using the audio channel to add log notes before I start the camera rolling, which isn’t particularly standard.
- I’d love to put one of these on a drone/UAV to sync to other cameras as part of a multicamera shoot
The project has 6 days left to run at indigogo and is currently only 50% funded, so it will be interesting to see whether the pro/semi-pro video community jumps on the opportunity to have a cheap timecode solution.