Late last year I borrowed my mother in laws DSLR camera for a weekend. 5 months later I returned it (following repeated requests), I loved it and the photos it made possible, and I also began planning some types of photo I’d like to take, like Star Trails. The (recommended) way of taking these with a digital SLR is to use stacking software, which involves taking lots and lots of photos from a tripod mounted camera, and then using software to put them all together.

I found that to do this you would need an intervalometer, a pricey piece of kit (well about £20+ but more than I wanted to spend), luckily there is an alternative for someone with an Android phone, an app called PhotoIRmote. This can trigger a camera using a simple home made Infra-red remote control that plugs into the 3.5mm audio jack.

Sadly the camera I bought myself (an Olympus E-PM1 following an epic clearout-fueled set of eBay sales) did not have an IR port. Luckily PhotoIRmote can operate from a cablemod. Sadly there appeared to be no cheap add-on bit for the camera (as seen in the guide) to connect to an Olympus RM-UC1 input.

So using the cablemod guide, and this triggertrap guide I devided my own cablemod for PhotoIRmote.

Not much else to say really, hope someone finds this helpful.

I got the Olympus connector from eBay; I bought a cheap USB cable and then used a sharp knife to cut away the moulding around the RM-UC1 connector.

Note; with my phone (a Samsung Galaxy S2) there is insufficient current coming from the audio jack to operate in bulb mode. Basically what happens is the transistor closes the circuit, but then the juice runs out and the circuit opens, and then closes, and then opens…… which in bulb mode makes the camera take a series of shots, not one long exposure. The best work-around for this, if you have the same problem, is to set exposure time from within your camera to the desired length/ longest length possible and then use the intervalometer to trigger a series of long exposures which you can then stack.