A review of the new Cactus X-TTL cross platform flash trigger firmware with HSS and TTL

One of the reasons I love shooting with Sigma camera bodies is the combination of the Foveon sensor that delivers great color and image detail with high quality and large aperture lenses like the Sigma 50-100mm f1.8 “Art.” that let me isolate a subject while turning the background into dreamy bokeh-filled canvas like this shot of my daughter.

Sigma sdQ with Sigma 50-100mm “Art” at 100mm f/1.8, natural light.

This combination can deliver some wonderful images however, if you’re like me and you enjoy using off-camera flash, having all that light entering your camera can quickly exceed the flash sync limit. The only two solutions are closing down the aperture – in which case you destroy potential for how creamy that background can be – or use ND filters to reduce the amount of light entering the lens.

The problem with ND filters is there are even more tradeoffs – it becomes more of a hassle to see and properly focus on your subject (depending on the strength of your filter), you are adding another layer of glass that diminishes the overall sharpness and image quality potential, and finally you need a more powerful flash to cancel out the strength of the filter. It blocks all light after all, not just the ambient.

Wouldn’t it be nice if we could just concentrate on the shoot without having to worry about sync speed limits?

Luckily, Cactus has been working hard to bring TTL and FP/HSS support via the existing Cactus V6 II radio transceiver with the soon-to-be released “X-TTL” firmware, which allows TTL for not just Sigma but Canon, Nikon, Pentax, and other otherwise proprietary systems.

We are delighted to offer firmware support for Sigma cameras and flashes. This includes remote power control, remote zoom control, wireless High-speed Sync, and wireless TTL with Sigma’s SA-TTL flashes. The same cross-brand support is also available on the Sigma X-TTL firmware.

– Cactus

Comparison between HSS Flash and Sync Speed Limited Flash.

I’ve had the opportunity to test this new firmware and not only does it enable me to exceed the camera’s flash sync speed limit but it also allows wireless TTL using Cactus’s own RF60x speedlight (with built-in transceiver). Additionally, you can attach a Sigma TTL flash like the wonderful Sigma 630 onto a second V6 II and enjoy wireless HSS and TTL along with the ability to remotely change flash settings.

Sigma EF 630

For the below shot of my son I set my Sigma sdQ-H to 1/4000s, f/1.4, and ISO 100 and the camera automatically transmitted the power settings to the flash through the Cactus V6 II system to produce this image.

Sigma sdQ-H, 85mm “Art,” with 60x90cm softbox camera-right.

Being able to do this without having to worry about the 1/180 flash sync or installing ND filters is not only amazing, it’s a game changer enhancing my creative freedom to make full use of camera and lens without worrying about sync speed limits.

Here’s another shot similar to the above, however this time it’s using the Sigma 50-100mm f/1.8 “Art” at the long end of the zoom range and wide open.

Here’s a small BTS video from my Instagram.

View this post on Instagram

A post shared by Paul Monaghan (@pmonaghanphoto) on Apr 7, 2017 at 6:30am PDT

Sigma sdQ-H, 50-100mm “Art,” 100mm, 1/4000s, f/1.8, ISO 100, flash camera-right.

Here’s a few more examples where I mix the large aperture of the “Art” lens with Strobe lighting to really isolate my subjects.

Sigma sdQ-H, 50-100mm “Art,” 90mm, 1/2500s, f/2.2, ISO 100, flash camera-right.

Sigma sdQ-H, 85mm “Art,” 1/4000s, f/1.4, ISO 100, flash camera-left.

And lastly a little creative shot with Aranel Cosplay using high speed sync to turn day into night while using flash to light the subject.

Sigma sdQ-H, 18-35mm “Art,” 1/4000s, 18mm, f2, ISO 100, flash camera-left, 2nd flash with green gel under her hand

For more information on the Cactus V6 II transceiver and/or the upcoming “X-TTL” firmware, please check out the Cactus website or the X-TTL microsite. For more information on the wonderful Foveon sensor and Sigmas own cameras then check out Sigma Imaging.

About the Author

Paul Monaghan is a portrait photographer based just outside of Glasgow, Scotland. You can find out more about Paul on his website, or follow his work on Instagram and Facebook. This article was also published here and shared with permission.

Kevin

“Being able to do this without having to worry about the 1/180 flash sync or installing ND filters is not only amazing, it’s a game changer enhancing my creative freedom to make full use of camera and lens without worrying about sync speed limits.”

Geez, everyone else has been doing this for decades now…!
- Paul Monaghan
  
  If you shoot canon or nikon yes, this is a first for Sigma unless you count using ttl optically and will work on fuji, pentax and others with the correct canera specific firmware.
  
  With the cactus trigger I can also use canon/nikon ttl flashs (with a v6ii mounted) and use them in TTL/HSS with my Sigma as it works cross brand.
  
  Normally I would just use the leaf shutter on my Sigma dps which let me sync flash at any shutter speed without any fancy stuff but them I’m limited to 14mm f4, 19,30,50 and 60mm f2.8 and its nice to shoot 100mm f1.8 at times so this opens up way more creative options for me.
Kriztoper

Thank you for the review. I do have a question, would you happen to know if they work for Sigma dp0Q – dp3Q or dp1M – dp3m?
- Paul Monaghan
  
  Yes they do :) although the hss part isn’t needed :)
  - Kriztoper
    
    Thank you, that’s awesome :D
    - Paul Monaghan
      
      no problem, just glad to help.
      
      If you don’t need TTL, the older v6 works well on the DP cameras and can give remote power of most TTL flashs (ones that support analog TTL) although not sigmas own flashes as they are Digital only :)
Bodson

Someone who actually uses a sigma camera? Lies thought they were just a myth :p. Good write up Paul
- Paul Monaghan
  
  Thank you kind sir :)
kgelner

From a practical standpoint if I wanted to use this system I would need two Cactus V6 II receivers, correct? One for flash and one for the camera…

Also I am right in thinking you’d not get HSS if you had something like a PocketWizard on the lights and a Cactus on the camera, right? I mention this as I sometimes go into other people’s studios to shoot where they already have wireless triggers set up on lights.

Lastly, you mentioned in another response that this system is not needed for the DP Quattro cameras. What is the flash sync speed on those systems? I’m having trouble finding specs, the only one I could find I think listed the DP2-Quattro at 1/1250, is that right?

Thanks for a very informative report.
- Paul Monaghan
  
  Hi @kgelner:disqus
  
  The DP cameras have leaf shutters that can sync upto 1/2000 (the max shutter speed) but going faster than 1/1250 causes the aperture to close so it can keep up. No HSS is needed for them but at times it can be hard to get a lot of flash power past 1/600, I think you would need the ability to set up delays on the flash to get the timing perfect.
  
  Cactus have there own flash, the rf60x which has a built in trigger giving TTL and HSS when used with the new X-ttl firmware on the v6ii so you would only need one trigger if you had one of them, if you want to use any other light you would need cactus triggers to connect them.
  
  For studio lights that can’t connect via the hotshoe to use TTL features the older v6 version 1 will work as you connect it through the 3.5mm jack, these are quite a bit cheaper than the v6ii units and still offer grouping and such.
  
  You could use the “powersync” feature to use pocket wizards or other radio triggers and get past the flash sync limit, people are already doing this without the X-TTL firmware as the original firmware supports HSS/Powersync.
  
  Powersync works with any flash as long as the flash has a delay longer than 1/300s it should be fine… my Godox ad600 which has a flash speed of around 1/220 at full power can work well in this mode but if I drop to 1/2 power I no longer get full coverage of the sensor as the light duration is too short but if I manually enable HSS on the Godox which forces it to pulse the flash I can sync at all power lvls but sadly if I change power using the Godox xt1 this is disabled… I was hoping to use the xt1 on the v6ii but doing that causes the canon version of the xt1 to freak out and I have yet to test nikon or other brand versions yet to see if they will work (if they do then you could get TTL/HSS using godox lights by using the cactus trigger to translate) but using two triggers will add more delays which could cause problems.
  
  I hope this helps :)
joe moloney

So how does an advertorial work again?
- Paul Monaghan
  
  I’m just sharing my thoughts on using the new cactus firmware and the creative opertunitys it opens up for my fellow Sigma users.
  
  Luckly DIYphotography shared it so it can reach more people, I wasn’t paid for any of the words or images I created for the article.
jadon

As a fellow Sigma Sdqh user I have been harrassing cactus for this for quite a while so this is wonderful news, beautiful pics by the way !
- Paul Monaghan
  
  Sorry for missing this. Thank you.