Just Scream to Trigger the Camera

By Haje Jan Kamps on at

If you came and visited us at the Mini Maker Faire in Elephant and Castle this weekend, you may have experienced me asking you (very nicely, of course), if you wouldn't please come shout at my camera. (I even asked one poor girl whether I could shout at her cupcake. Everybody agreed that this was, without doubt, the worst pick-up line ever).

Anyway, the results from the ScreamGrab photo booth were amazing. The premise was simple: Use the Triggertrap Mobile app with the sound threshold set to Very Loud Indeed™.

The idea being: If you really have to give your vocal cords a workout to trigger the camera, you're going to get something special in a portrait. And yes, we ought to admit that this was inspired largely by this photo Mike Rickard posted to the Triggertrap Flickr Pool a few months back.


The Results

Before we delve into the nitty-gritty of the technicalities, let's take a look at some of the results (of course, if you fancy taking a peek at the full collection, there's more than 250 to look at over in our Flickr set). Here are some of my personal favourites:

I wouldn’t want to get in a shouting match with her...

A rather unusual family portrait.

The obligatory theatrical “Noooooooo!”

My absolute favourite of the day.

A great howl.

Look at that passion!

Awesome hair action.

Triggertrap team photo.

See?! We told you it was loads of fun!

So... How is it done?


The Basics: Getting the Shot

So, at a very basic level, all you need to do is to get an audio trigger that will take a photo when the volume hits a certain level, and a camera. In our case, we decided to use the Triggertrap Mobile app (surprise surprise!), but we discovered to our horror that the app itself was way too sensitive: Even with the sensitivity threshold all the way to the top, you didn't really have to put your back into the scream to trigger the camera (in fact, speaking normally was loud enough to snap a shot). Uh-oh.

In the Android version of the app, there's a separate slider for sensitivity, but we don't have that level of control over the iOS app (and I did want to use the iPod Touch I had brought along, so that I wouldn't have to tie up my phone all day).

After a spot of last-minute panicking, we discovered that there was a very simple, and delightfully low-tech solution to this: I simply stuck a small piece of packaging tape over the microphone on the iPod Touch. Hacky? Well, yes, but who cares -- it did the trick!

With the tape in place, we were able to use the sensitivity slider to fine-adjust the triggering threshold. Perfect for what we were trying to do!

In theory, with the app configured and hooked up to the camera using a connection kit, that's all you need to get the photo. Stick it on a tripod, and you're good to go -- really, everything else is showmanship.

But this is a fair, after all, and we're naturally frightful show-offs. Just look at that team photo again for evidence.

The set-up so far:

Canon EOS 6D (but any SLR will do, really)
Sturdy tripod
Triggertrap Mobile Dongle + connection cable
iPod Touch

Take a look at the Triggertrap blog to see how to take it up a notch for high-quality photos, and how they were able to juggle the workflow of instantly publishing the photos.

- Read about Haje's Triggertrap success with Kickstarter here.