High-Speed Sync - Canon Macro ring lite MR-14EX II Instruction Manual

c High-speed SyncN
With high-speed sync, the flash can synchronize with all shutter
speeds. This is convenient when you want to shoot in the aperture-
priority AE (f) mode (open aperture) with background blur.
With high-speed sync, the faster the shutter speed, the lower the guide
number will be.
If the set shutter speed is slower than the maximum flash sync speed,
<F> is not displayed in the viewfinder.
To return to normal flash shooting, press function button 4 <Y> to
turn off <c>.
30
Display <c>.
Press function button 4 <Y> to
display <c>.
Check that <F> is lit in the
viewfinder.