The specific shapes of light modifiers come into play in how they shape light and how we apply them to our subject or scene. If we zoom into the eyes of our subjects and take note of the shape of the catchlights we are creating, we can begin determining which shape of softbox is the most appropriate for a specific shoot.
The large rectangular softboxes you are most likely to find in a studio were originally designed to mimic big, soft window light. The catchlights they leave in the subject’s eye look natural, almost as if you happened upon someone gazing out the window on an overcast afternoon.
This same rectangular catchlight might not strike you as so natural if you were to notice it in the eyes of model, say in the middle of a field for example. When looking around you’ll notice most outdoor light sources are round and up high: street lamps, overhead lights, the sun, etc.
For the kind of work I do the Apollo Orb has quickly become my go to lighting modifier. I love the great outdoors and you can’t beat natural light some days. However, when I need to recreate the sun and create a round catchlight, the Orb is what I rely on.
Next time you’re in the mall or a department store, take a look at the massive photos they have everywhere in the clothing aisles. Note the models eyes and see if you can figure out what modifiers the photographer used. It’s great practice!