Toronto-based Destination Wedding Photographer Derrel Ho-Shing created a video demonstrating the difference of natural light, flash, and high-speed sync. This might seem trivial at first glance, but having the same model, same setting, and three lighting approaches makes it obvious which setup is the winner, at least to me.
For the comparison test, Ho-Shing used a Canon 5D Mark IV and Sigma 85mm f/1.4 Art lens. The demonstration starts with a natural light setup. With this beautiful lens you get a desired separation between the model and the background. This might be an on-the-go setup for a majority of photographers.
Next one is the regular strobe setup. As you can see, the lighting on the subject is pretty good, but the background appears too busy. In order to get the proper lighting the photographer has to go to f/5.6. Surely this is not the best idea when you are shooting with the beautiful Sigma 85mm f/1.4 Art lens.
To use the full potential of the lens, Ho-Shing uses high-speed sync. This allows him to go back to f/1.4, darken the background, have separation, and create an overall more commercial look.
Of course you can also consider using ND filters for similar effects with high-speed sync like in the photo below. That is what I have been doing for a long time before high-speed sync was in the wide market. A detailed talk on ND filters is described in one of my previous articles, "The Ultimate Guide to Dramatic Skies in Portrait Photography."
What is your favorite lighting setup out all these and which one do you use most often?