How to Choose the Right Size Softbox
If you are planning to use a softbox for your next set-up, you should think about more than simply what shape to choose or where to put it. The size is just as important – perhaps even more so!
The larger the light source is in relation to your subject, the softer the light will be. This simple fact is one of the most important lessons to learn about light, and for this reason, choosing what size of softbox to use will be one of the most important decisions that you will make prior to a shoot.
For instance, if you choose a larger softbox, you will get a much more open, softer light that more closely resembles daylight. If, on the other hand, you go for a smaller softbox, you will get a harder light with richer contrasts, reminiscent of interior light.
Take a closer look at the next two images in this article. The first image (1) was shot with the larger Profoto RFi 4×6’ while the second image (2) was shot with the smaller Profoto RFi 1.3×2. While the first image looks almost as if a window was in the room, the second image looks more as if a lamp is turned on. The lighting also affects the overall mood of the image. The second image is undoubtedly moodier and more dramatic.
Note that we used only one rectangular softbox for both images. Also note that the light was standing in the same spot with exactly the same distance between our model and the softbox diffuser (when using a softbox, this is the distance that actually matters – not the distance between the model and the flash head).
In conclusion, by choosing between a large and a small softbox, we can drastically change the light and the overall mood. Needless to say, there is no right and wrong. It all boils down to deciding on what you want to achieve, and then choosing the right softbox to do the job.