Phottix Lasso flash trigger

I’ve been evaluating the Phottix Laso flash trigger system alongside my existing Canon RT flash units to see how it operates.

Phottix got in touch and asked me if I’d like to have a look at their Laso units and give my thoughts her on the blog. I was supplied with a Laso trigger and receiver by them for the review.

The concept of the Laso system is that it fits in with the Canon RT radio system. This means all the features you might expect from your Canon camera and flashes are possible, plus you can intermix the Phottix Laso with other Canon RT components. For some photographers the receiver is a good way to be able to use existing Speedlite 430eX II / 580EX II alongside the RT system devices.

Phottix Laso flash trigger transmitter

Phottix Laso flash transmitterThe Laso transmitter works with the Laso trigger receiver and can also control the Canon Speedlite 600EX-RT and Speedlite 430eX III-RT flashes. In many ways you could call it an alternative to the Canon Speedlite Transmitter ST-E3-RT. One of the key differences is the addition of an AF assist light on the Phottix Laso transmitter to help your camera focus better in dark conditions. IF you have an EOS 5D Mark III you’ll know that they can sometimes struggle to see in the dark for focus, the Phottix transmitter is one way to improve your camera’s AF performance in low light.

The Laso runs on two AA batteries, and the display and controls are very similar to my Canon ST-E3-RT. One minor difference is that the Laso has a simple push button for on/off as opposed to the three position lever switch on the ST-E3-RT. I found that I can power on the Canon transmitter by feel, yet I have to check that I actually turned on the Laso or wait for the beep when a slave is switched on. Set C.Fn 20 to 1 on the transmitter so that it will beep when all the slaves are connected and ready to flash.

All the modes you’d expect are found on the Laso.

  • E-TTL with up to three groups and ratio control
  • Manual with up to three groups with individual power level control
  • Multi flash mode
  • Group mode

In my trials I’ve used a mixture of E-TTL, manual and group mode much like I would with my ST-E3-RT and they all work as I’d expect. High speed sync can be set on the Laso transmitter and the flashes then will switch to HSS mode when needed.

Phottix Laso transmitter

Phottix Laso Transmitter

All the custom functions (C.Fn) and personal functions of the Laso match the Canon ST-E3-RT, there’s an additional personal function P.Fn 08 on the Laso to disable the AF assist beam if necessary. You can also set and control the flash features from a 2012, or later, EOS camera menu system.

The transmitter works and in my tests I was able to set it as a linked shot master or slave and have it work with my existing Canon ST-E3-RT. Phottix adds a USB port to apply firmware updates to the transmitter though I haven’t needed to do this, and there appears to be no updates from Phottix for the Laso since it’s launch in September 2015. At least you can do updates yourself and the trigger doesn’t need to go back to the manufacturer for updates like my Canon did earlier this year.


One of the missing elements of the Phottix is weather and dust sealing, the ST-E3-RT is weather sealed just like the 600EX-RT flashes are, the Phottix is not. It does have the sealing around the flash foot, but the battery door has no weather seals, nor around the buttons and dials. Whilst I’m being picky the indication for which way round the batteries fit is less obvious than the Canon. You have to look for a + and – symbol moulded in to the black plastic on the Phottix, the Canon has a white painted indication inside the battery chamber that is clearer.

One of the Laso claims is a 100 meters working radio range, the Canon ST-E3-RT specification is only 30 meters. Make sure to read further down this review as I spent a morning testing the range with surprising results, and a lot of walking back and forth 🙂

Phottix Laso flash trigger transmitter


Here’s one of my shots from a location test shoot with Emma. The entire shoot was done with the Laso transmitter, Laso receiver, Speedlite 580Ex II and a Speedlite 600EX-RT. For the picture, I used Group mode with the main 580EX II in E-TTL and the 600EX-Rt in manual. The 580EX II and Laso receiver is in front of Emma in a small Lastolite Ezybox II Speedlite and the Speedlite 600EX-RT is on the ground some way behind her.

You can get the Laso for around £149 from Wex and Calumet, whereas the Canon Speedlite ST-E3-RT is £239 from the same dealers [prices as of 23 July 206]


The Phottix Laso is a lower cost version of the Canon ST-E3-RT; it does all the same functions, is easier to update and has a built-in AF assist light. It lacks weather sealing and I found the on/off button less easy to operate by feel. For me the Laso has become a second trigger in my bag to go on a second body or for sharing lights with a fellow photographer.

Phottix Laso flash trigger receiver

Phottix Laso flash trigger receiverWhen Canon launched the radio flash system in 2012 the Speedlite 600EX-RT was horribly expensive and all the existing 580EX II and 430EX II flashes could not be used with the radio system. Since that time independent companies have created radio receiver modules, that fit on the hotshoe of the older 580EX II and 430EX II flashes, to allow them to work within the RT system. The Phottix Laso flash receiver is one such device.

The Phottix Laso receiver fits on the hotshoe of your flash, and converts radio control messages from an RT transmitter to the commands the 580EX II understands. As I have moved on all my non-radio flashes I acquired a Speedlite 580Ex II for the test and didn’t test with 580EX or Speedlite 430eX / 430EX II. I believe the Mark II flashes will work but probably not the Mark I versions.

Phottix Laso receiver

Phottix Laso receiver with Speedlite 580EX II

In use, you simply leave the 580EX II in E-TTL mode not set as a master or slave and let the receiver do all the work. You’ll need 2 x AA batteries in the receiver making a total of six required for each slave. I used Eneloop batteries in the Laso kit with no trouble.

Next to the small LCD display there are four buttons to change the settings for the radio channel: 1-15 or AUTO, ID: 0000 – 9999, Group: A-E and to release the shutter of the camera. There’s also a test button to fire the attached flash and the power button. Once the receiver is on, you may not need to change settings, so it is possible to LOCK the receiver to avoid the keys changing the group, channel or ID inadvertently.

Phottix Laso receiverThe plastic of the receiver body seems to be strong enough, remember it’s supporting the weight of your flash and batteries – typically about 500g. On the foot of the receiver there’s a cold-shoe made of metal with a regular 1/4-inch tripod thread in the middle. This makes it easy to fit the receiver and attached flash to existing mounts you may be using. I did manage to fit it in the quad bracket I sometimes use with my larger soft boxes.

Around the edges of the unit there are three sockets; micro USB for firmware updates, 3.5mm flash socket to allow the unit to trigger studio flashes, and a 5-volt DC input to power the unit if you need to install it somewhere for a long time. I tested the unit with some old Elinchrom BX flashes and I could trigger them with the Phottix as expected. There’s a short 3.5mm to 3.5mm cable in the box and a 3.5mm to 6mm adapter should you need it.

The receiver supports E-TTL and Manual modes only even if your flash provides Multi or External Auto modes – the 580EX II does have these. You can use it with ETTL, Manual or Group mode on the transmitter and high speed sync is supported too.

Currently the Laso receiver is £99 from Wex and Calumet. [prices as of 23 July 206]


If you have the older Speedlite 580EX II flashes then this will get them off camera and working with the RT radio system. The size and shape of the receiver may be an issue with some light modifiers. There’s plenty of 580EX II flashes out there, look on eBay for them, and this receiver makes a good option to make them radio controlled as part of the RT system.

Personally I’m not using the receiver very much as I have 600EX-RTs and 430EX III-RT flashes. The RT flashes are more compact and need only 4 batteries per slave as opposed to six for the Phottix Laso + Speedlite 580EX II combination.

Phottix Laso radio range tests

One of the key differentiating factors of the Laso products is the claimed 100 meter operating range, this is more than 3x the range that Canon claims for their RT system devices. So with this in mind I set out to see how far I could get the Laso triggers to work.

Phottix Laso range testing

Range testing the Phottix Laso


Phottix Laso triggerFor the test I put the Laso trigger on the EOS 7D Mark II, fitted an EF 70-200mm f/2.8L IS II USM + EF Extender 1.4x II and put it all on a tripod aimed at a wide open section of the local park. For the flashes I put the Laso receiver on the hotshoe of the 580EX II and fitted it to a light stand. The camera and flash were set at a height of 1.7 metres from the floor since this is reasonable for a handheld camera and light on a stand. With a trusty tape measure in hand I started measuring out distance. I measured to thirty meters and started there, it all worked so I just added 10 more metres and moved on. The key was making sure that I was still in the centre of the frame in the viewfinder, so I need to keep in contact with my assistant for the day via mobile.

So that I was sure the radio was fully working I had set high speed sync on the transmitter and used the buttons on the Laso receiver to trigger the camera shutter. If the flash fired, that meant the transmission had gone from the receiver to the camera and back. Camera settings were manual mode with the aperture at f/4, shutter speed 1/1000s and ISO 100. The lens at 200mm, 1.4x extender and 1.6x crop factor.

100 meters radio range no trouble

Using a Lastolite Speedlite twin flash bracket I actually tested two devices on the light stand at the same time; a regular Speedlite 600EX-RT and the Phottix Laso receiver with a 580EX II. At each 10 meter distance I triggered the camera from the Phottix Laso and the Canon 600EX-RT. From the camera position I’m on the left for the Phottix and on the right for the Speedlite 600EX-RT

Phottix Laso triggerQuickly I reached 100 meters with absolutely no problems so continued on. The first glitch came at 190 meters; the Speedlite 600EX-RT that was also on the bracket kept losing the link light so I changed the orientation of both flashes from horizontal to vertical on the flash bracket and the link light came back on. This is likely to be an antenna orientation issue, maybe with the Phottix the orientation helped and not so for the Canon, but when the orientation was changed both still worked.

Phottix Laso triggerI started to get a sense that this would be a long day, had it in my mind that I’d stop at 200 meters (656 feet) if I got that far. I did as you can see below.

The reality is that this is pretty impressive, I’m really unlikely to need to place lights 200 meters from the camera. Even more impressive is that I turned off both the Phottix Laso receiver and the Speedlite 600EX-RT at 200m, then switched them on and they both reconnected instantly.

Phottix Laso range testing

At 200 meters, triggered from Phottix Laso receiver

Phottix Laso range testing

At 200 meters, triggered from Speedlite 600EX-RT

The pictures above show me 200 meters from the camera, with about a 450mm focal length lens (200 x 1.4 x 1.6). And they are still using High Speed Sync and triggered from the flash. The sun had gone in and it’s a 400 meter walk to and from the camera to change the exposure!!!

Just for a laugh I headed back to the camera, swapped the Laso trigger to the Canon Speedlite Transmitter ST-E3-RT and then went back to my testing. The Canon trigger worked just as well as the Laso trigger.

Range testing: my thoughts

I was seriously impressed with the 200 meter range, I’d expected the system to stop working at around the 100 meter mark, so to achieve double that is impressive.

Indoors with lots of people, concrete, wiring and water you may not be able to achieve the same results.



About the author

Full-time photo tutor and photographer. I love to share my knowledge and skills to make photos, videos and teach others. I write books and articles for photo magazines and I always have at least one Speedlite flash in my camera bag