Here in Cyprus I usually get the problem with very harsh light relatively early in the morning. Without fill flash normally 8:30 I have to stop. Cloudy sky still exist in the spring but not from May to October, there I get Sun pure. With Flash I can also make usable photos in this Time. There are of course also special places, as for example in the Paphos forest or Troodos Mountains, where to use an Flash always makes sense.
I'll usually start my Flash shots with -2 EV Aperture Setting on the Flash. The Menu on the EOS 1D Mark IV and 5D Mark III shows me the Flash settings in the Display, as well as the exposure setting on the Light scale in the Display. I look also on the exposure counter to be at -1/3 Aperture set. Importand is also to switch the Flash on high speed sync.
Lighten in difficult light conditions I use a Flash for nature photography more and more often. I use on the Canon EF600mm / f4L IS USM already a Kirk lens foot replacement LP-55. So I have decided for the macro holder by Kirk directly mounted on the lens foot. The advantage for me is that the entire Flash system very high and laterally adjustable from the axis of the lens can be mounted. The whole system is mounted for use in the tent (Doghouse) thus completely outside of the tent and in the Pan, nothing hindered.
The Set therefore consists of following parts:
1 x Canon Flash 580 EXII
1 x Better Beamer
1 x Kirk single Flash bracket FB-9
1 x NOVOFLEX NEIGER 19 with Flash foot
1 x Flash cord Meike digital OC-E3.
The Set can be seen in the following images.