Let’s Make Some Noise!

I’m still getting used to my new CameraAxe5 Arduino shield and what it can do, so I thought I would take things slowly and try some simple experiments first. Today’s plan was to have the camera and flash fire when I clapped my hands – just like the perfect servant it should be!

In order to keep things as simple as possible, I decided not to photograph moving objects to begin with, but got Gerald Jr to pose for me in my little portable studio setup. He stands and does what he’s told. The CAS5 and sensors/outputs were set up as follows:

Sensor input and device output setup for Microphone experiments
Sensor input and device output setup for Microphone experiments

This is how the values were set on the Advanced Sensor Menu of the CAS5:

Device1 Device2
Trig Sen Sensor1 Sensor1
Delay ms 000.0 500.0
Bulb sec 02 00
Prefocus No No
Sensor1 Sensor2
Trig Type Threshld Low
Trig Val 080/26 000
Power On On

Device 1 (Camera)

Trig sen – set to trigger from Sensor 1 (the mic)
Delay – 0ms – the shutter opens immediately when the sensor detects above its threshhold (see below)
Bulb sec – 2 – hold the shutter open for 2 seconds
Prefocus – no, don’t attempt to focus (was set to manual on lens)

Device 2 (Flash 1)

Trig sen – set to trigger from Sensor 1 (the mic)
Delay – 500ms – the flash fires half a second after the sensor detects/opens the camera shutter – this is to allow for shutter lag in the camera, so it should be fully open by the time the flash fires
Bulb sec – 0
Prefocus – no

Sensor 1 (Microphone)

Trig type – threshld – the microphone triggers the devices once the detected volume exceeds the trigger threshold (set below)
Trig val – 080/26 – the ambient noise in the room was around 20-30 units (the second value), so I set the trigger threshold value to 80. Noises exceeding this (like a hand clap or cough!) would trigger the devices
Power  – on

Sensor 2

Nothing connected

So, without coughing too loudly, I clapped my hands and my robotic minions took this lovely little picture of Gerald Jr posing for the camera:

Gerald Jr says Hurrah!
Gerald Jr says Hurrah!

Here’s a little video showing the setup in action:

I realise it’s early days yet, but I need to get to grips with the basics before I dive headlong into colliding water droplet territory! One step at a time…

200ms delay - not enough action in the frame
200ms delay - not enough action in the frame
500ms delay - all the action has happened
500ms delay - all the action has happened

Later on, I used a similar setup to the above for my Day #1402 shot of falling pasta. This time, I set the camera to 4s exposure, with a 2s delay on self-timer and manually firing the shutter with the remote release. Once the camera warning light went out after 2s, I dropped the pasta onto the background. The flash was set to fire after 300ms of delay via the CameraAxe, so that there was still some pieces in mid-air. This delay was worked out by trial and error – firing immediately gave too little in shot, and firing after about 500ms meant it was all stationary on the floor.

The room was dark enough for a 4s exposure to register a black frame without any flash going off – the camera was at ISO 200 and f/14, with the two flashes set to 1/128 power. I had found previously that firing the camera via the Arduino setup and having less than 500ms delay wasn’t giving enough time to allow for shutter lag. But with a much longer exposure and manual firing, I still had “time” to set the flash off via the microphone hearing the pasta hitting the deck, before the shutter closed again after 4s.

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