Godox X2T and focus assist light

I have a Godox X2T that I use with my Canon R5 and Godox 860II. It does the job, allowing me to get the flash unit off the body. However, as my intended use for the setup is macro photography, often in the dark, it would be nice if I could get the focus assist beam to work on the X2T wireless transmitter. I have googled the issue, and it seems there may be solutions for Sony, for example, but I haven't been able to get it to work on my Canon R5. Any suggestions?

There's a bigger issue going on than whether or not the AF assist turns on.

It's that you're shooting a mirrorless camera.

Most AF assists are designed for SLRs/dSLRs. In a dSLR, you have three separate sensor arrays: one along the back for image capture, one on the floor of the camera for autofocus, and one up near the viewfinder for exposure metering.

On a mirrorless camera, you've only got one sensor doing all three jobs at the same time. And because you would prefer a color image to a B&W one, that sensor is sitting behind a Bayer filter. And for every four photosites, two are covered by green filters, one is covered by a blue filter, and one is covered by a red filter, so you get RGB values for each pixel of the image that can be interpreted as a specific color value.

Red light cannot pass through a green filter, so half your sensor can't see it.

Only minimal red light passes through a blue filter, so now, say 70+% of your sensor can't see it.

And some sensors put their PDAF areas in hybrid AF systems only behind the green filters (no idea why).

Result? You need a white (or possibly green) AF assist, not a red one, for the sensor to actually detect the AF assist lamp.

SLR AF assists are near-infrared (both IR and visible red) lights, 'cause, remember, there's a separate array that's not behind any filters at all on the floor of the camera for autofocusing, and that sensor array is infrared sensitive, too. On the image sensor? You've also got a UV/IR cut filter to keep your visible light colors from being thrown off by UV/IR sensitivity on the sensor (google Leica M8).

The X2T? It has a red/IR AF-assist lamp for SLRs. At this time, most mirrorless camera simply leave AF assist inactive, because it won't help with traditional AF assists. Sony's starting to build white LED AF-assists into their cameras, but at this time, there's no really good answer for this.

Wow, you could print that out as a chapter in a textbook! Very informative!

I have decided to attach a mini power bank to my X2T via velcro and insert a USB LED reading light with gooseneck and simply use that when needed. Actually, since I more often use manual focus for macro, this should work.even better.

Thank you very much for the reply!

Focus Assist Beam Works on Mirrorless Cameras!!!
Hey everyone, here are the instructions for using the IR Auto Focus Assist Beam Via the Godox X2T for Sony and probably for other mirrorless cameras. Here are the steps I used:
1. Attach the Godox X2T to your mirrorless camera’s hotshoe.
2. Attach the Flash (I’m using Flashpoint R2 Li-on flash) onto the Godox X2T’s Hot Shoe to secure the flash. Make sure that it is not wobbly.
3. Turn on the Godox X2T.
4. Turn on the Focus Assist Beam button on the side of the Godox X2T Trigger. It should be the button closest to the camera lens.
5. TURN OFF AF-C MODE!!! Focus Assist Beam does NOT work in AF-C (Continuous Focus Mode).
6. Select AF-S Mode on the focus dial/setting.
7. Set the Flash Power and you should be good to go!
8. It’s such a rush seeing that IR Grid finally working!
9. Success to you all!