R5 and 580EX-II - No red AF assist beam?

[Always-Learning]

I have a 580EX-II and on my old 40D, it fires an AF assist grid when needed. On my r5, an intermittent flash is used instead. Another post indicated with a different mirrorless (maybe r8?), the manual makes clear that’s “what happens”. The r5 manual doesn’t say anything on the subject that i can find.

Grateful if anybody knows why the red AF assist isn’t used and better, if there is a solution so it will work on an r5. Thanks!

[deebatman316 · Accepted solution]

There IS NO way to make the old school "IR" AF Assist Beam work on mirrorless cameras. It cannot detect the AF Assist Beam at all. It can see Intermittent Flash Firing because its visible white light. All mirrorless camera systems won't fire the Red AF Assist Beam at all. All of Canon's speedlites automatically switch to Intermittent Flash Firing on the EOS R series. Even if the speedlite has a choice between IR and Intermittent Flash Firing. The camera has the ability to override the speedlite's AF Assist Beam projection setting. For speedlites with a choice between IR and Intermittent Flash Firing. With the speedlite set to Intermittent Flash Firing and a color filter or flash diffuser attached the camera body emits an LED AF Assist Beam. Since Intermittent Flash Firing is DISABLED when a color filter or flash diffuser is attached to the flash.

[Always-Learning]

Ah - i assumed it was just because the speedlite is old - a compatibility thing. Didn’t realise the mirrorless can’t actually see the red. A shame but thanks for the detail - at least that’s clear!!