Time lapse and sensor-trigger your camera with a Triggertrap iOS app

Using an iOS device to trigger your dSLR or system camera’s shutter, aperture and exposure is a tempting idea but it’s not straightforward to implement. The experiences I had with the Triggertrap Mobile and Triggertrap Timelapse Pro were mixed. Some features work well, others much less. Triggertrap Mobile lets you use an iPhone or iPad as a control device that allows you to press the shutter button, create timelapses, HDR image series, bulb ramping, and sensor-driven photos.

The Triggertrap system is a combination of hardware and software. The hardware consists of cables and a so-called dongle. The dongle is at the heart of the system and translates the app’s commands into simple shutter release commands, while also protecting the iOS device against power surges that the camera or speed light might generate. The dongle plugs into the headphone jack on your iOS device. The micro-jack port on the dongle accepts camera-specific cables. I received a cable for the Sony Alpha 700 and the A7. Unfortunately, I was to send back the A7 a day after the cables arrived, so I had no chance to test it with Triggertrap.

triggertrap cables

Further, optional hardware includes a Triggertrap Flash Adapter, which is a cable that plugs into the dongle on one side and into a dual flash hot shoe on the other. The hot shoe allows you to mount and fire two speed lights simultaneously. An extension cable is another accessory you can buy to complete your Triggertrap system. The extension cable extends the micro-jack side of the system and allows you to keep your iOS device separate from the camera (about 1m in total).

The Triggertrap system depends on two things:

  • The audio on your iOS device, which must be as loud as possible. So turn off loudness limitations on Music playing in the iOS settings and turn up the volume on the headphones sound-out
  • The camera settings, which must allow for remote operation at the fastest possible speed.

A fast and responsive camera is a necessity to use the system successfully. Many of the problems I encountered with the A700 were partly due to the slow response of this mirror-based dSLR. The free Triggertrap Mobile app allows you to compensate for this. You can set sensor delay and pulse length. The latter depends on your camera. The shortest pulse is 30ms and is only useful when controlling speedlights. I needed a pulse length of 500ms for my A700.

triggertrap flash adapter

Triggertrap also offers another app: Triggertrap Timelapse Pro. This is a paying app and allows you to create complex intervals for equally complex time lapse photography. However, the app was totally unusable with the A700. It would only fire the camera at random intervals. I informed the developers of the problem and told them it looked like a pulse length problem. A fix will hopefully be part of a next update.

Triggertrap Mobile

The Triggertrap Mobile app comes with a decent user guide recommending to set your camera to manual focus and in some cases to bulb exposure. The next thing you’ll have to do, is set the sensor delay so that you are sure the camera won’t fire before you’re ready (e.g. get out of the frame with a self-portrait), the sensor reset delay (which defines the delay before taking the next photo) and that pesky pulse length.

When you’re working with the Flash Adapter, there are default values that you will find in the Flash Adapter user guide. They differ considerably from controlling a camera as a flash is much faster.

Triggertrap Mobile has several cable release modes, including a self timer. The next group of capabilities refer to time lapse photography. There’s a simple time lapse mode, and an entry that refers to the Timelapse Pro app — which, in my opinion, should have been a simple in-app purchase.

triggertrap dongle

An interesting feature is a TimeWarp time lapse mode. This is a mode that allows you to create time lapses with a speed curve. With it, you can increase the number of shots at the beginning and end of the sequence by changing the curve. It’s cleverly designed and very easy to use. DistanceLapse is yet another time lapse mode, which depends on your iOS device’s built-in GPS or FireWire distance measuring system. It worked with my non-GPS iPad Air 2 when I was indoors, but it’s really meant to create lapses from inside a driving car, for example.

There’s a mode called Star Trail, which speaks for itself and one that is called Bramping, which refers to basic bulb ramping. Triggertrap and probably any other app that depends on your iOS device’s capabilities does not support advanced bulb ramping, which includes shifting the camera’s ISO value. There’s only one device I know of that supports this and it’s Promote Control.

I struggled to make Triggertrap’s bulb ramping work, and finally succeeded by setting up the camera to its fastest settings — which included changing a lot of menu options. With any other camera settings, the A700 would only respond after two or three shots into the process.

Time lapse photography can consume a lot of battery power, which is why Triggertrap comes with a number of power saving features. Still, I think it would be wise to have an external battery powering the iPhone or iPad when you’re using it to control time lapse photography.

What doesn’t work that well

Sensor modes don’t work all that well. The interface is clever and user-friendly enough. You set the minimum level of sensor sensitivity dragging an innermost circle on a disc that represents the sensor’s input and the sensitivity. It immediately shows you how well the sensor response was received by the app… but not by the camera.

triggertrap sound sensor

I found that with a low sound trigger setting, you will often have other sounds that are as loud or louder even than your target setting — the camera’s shutter, a bump of your hand against the table — which will result in endless triggering of the shutter, until you hit the stop button.

How you would use Vibration mode is a bit of a mystery to me. It responds to your iOS device being shaken or picking up motion by vibrations.

The Motion sensor uses the camera to “see” motion. That didn’t work too well. I tried it with a subtle motion right in front of the camera, firing a disposable cigarette lighter. Nothing happened. It only worked when the motion was rather violent, like waving my hand. It’s a mode I wouldn’t trust to shoot wildlife with, for example.

Finally, sensor mode has one feature that does work well, which is Peekaboo. It works together with the facial recognition feature of your iPhone or iPad. This one worked well almost all of the time. You can track multiple faces, but I couldn’t try that out as I’m alone.

Advanced features

Triggertrap Mobile supports LE HDR (Long Exposure High Dynamic Range) mode. This is also known as Bulb HDR, a basic version of remote controlled HDR shooting. It allows you to take a set number of shots at different exposure lengths. Triggertrap’s mode requires the camera to be in bulb mode, which means it will only work well with exposures above 1/15 at least.

The LE HDR Timelapse mode allows you to create a series of LE HDR images automatically — a time lapse series. I didn’t try that out. There’s also a Wearables mode I didn’t test because I lack the wearables and a Wi-Fi mode I didn’t test for the same reason.


The Triggertrap system is a brilliant concept, but it depends on an iOS device’s capabilities and on you mastering the capabilities of your camera. Still, the Triggertrap Mobile app allows you to be creative with a camera in unexpected ways. The question is whether you’re better off with a Promote Control or a Hahnel Captur Module Pro system.

The answer to that question will be answered in large part by the price and whether you’re a professional or advanced amateur. A Triggertrap system costs €68.81 without the iOS device, of course. A Promote Control costs around €350, while a Captur Module Pro system with the included IR transmitter, full advanced time lapse capabilities and built-in sensors for light, laser, infrared, sound and auxiliary sensor equipment costs about €91.50.