Canon EOS-1D X Mark III Af Setting Manualbook page 85

Electronic 1st-curtain
This mode has a shutter sound but can
be used for flash photography and has
less distortion than the electronic
shutter.
2nd-curtain. The difference from the electronic shutter is that
it can be used for flash photography and has less rolling shutter
distortion than the electronic shutter.
Mechanical
The mechanical shutter is used for both
the first and second curtain's shutter.
so the mechanical shutter setting is effective when shooting
with an emphasis on beautiful out of focus highlights. As
with the electronic 1st-curtain, rolling shutter distortion is
less than that of the electronic shutter.
During Live View shooting,
the default shutter mode is
[Elec. 1st-curtain]. This is a
system
electronic shutter for the
1st-curtain
mechanical shutter for the
[Mechanical]
mechanical shutter for
both the first and second
curtains. In [Elec. 1st-
curtain], there are rare
cases where out of focus
highlights may get cut off
85
that uses the
and the
uses a