Vivitar DF-372-CAN flash question

[Molew]

Greetings TPF members, new member here, almost as new as a photographer. My question today involves the flash unit above, mounted on my Canon 80D. How do I turn off the flash unit's Auto Focus beam?? That beam pattern shows up on most of my flash images, even when the flash is set to manual or semi-automatic modes.

Anyobe familiar with the process for turning off the flash unit's auto focus beam? Besides a piece of duct tape?

 

[RowdyRay]

Menu 6 under C.Fn II: Autofocus

 

[Molew]

That menu option likely works as intended with a Canon flash, but unfortunately has no apparent effect on the Vivitar flash.

Cycled power on and off on both camera and flash, tried setting other options within that menu, but still have the AF in the top right of the flash LCD screen.


Any further suggestions? FWIW I do intend to buy a Canon Speedlight and use this flash as a slave, if possible.