R5/R3 high speed sync does not work in aperture priority mode

[ngrinerphoto]

I used to do this all the time on my DSLR cameras but can't seem to make it work on my mirrorless. Is this no longer an option in aperture priority and only works in manual mode? 

[deebatman316]

What speedlite are you using Canon or a 3rd party flash system.

[ngrinerphoto]

EL-1 and 600EXII-RT

[deebatman316]

Can you set high speed sync on the speedlite. Or can you do it via the speedlite control menu. (The camera's menu screen).

[ngrinerphoto]

I can turn it on either through the camera menu or the speedlite. Turning it on isn’t the issue. It’s showing that it’s on. Both my mirrorless cameras just won’t go above the max normal sync speed in aperture priority but doesn’t have a problem in manual mode. 

[deebatman316]

What happens in Shutter Priority Mode.

[ngrinerphoto]

HSS does work in Tv. I wonder if Canon knows about the HSS Av issue and if so, what the reasoning is for not allowing for it like they did on their DSLR cameras. No issue with it on my 5D4 or 1DX2.  

[deebatman316]

High Speed Sync does work with Av Mode on Canon DSLRs. There has never been such restriction. What Shutter mode are you using full mechanical or Electronic First Curtain.

[ngrinerphoto · Accepted solution]

I actually think I figured it out but with a caveat. If you go into "external speedlite control" you can scroll down to "slow synchro" and select 1/200-30, 1/200-1/60 or fixed at 1/200. 1/200 is the factory setting and it will always be 1/200 in Av mode regardless of ISO and if you have HSS on UNLESS you change it to 1/200-30 or 1/200-1/60. When you select one of those two options, it allows you to use HSS in Av BUT if you're ever in a darker environment with with a strobe on, it'll take your shutter speed all the way down to 30 seconds or 1/60th of a second vs keeping it at 1/200 all the time.

[deebatman316]

There should be a setting that says 1/200-30 sec Auto. Does the camera not give you that choice at all.