Posted January 6, 2015 by Gavin Hoey in Videos

Softbox Size vs Soft Light

One of the primary uses of a softbox is to give soft lighting, but with so many sizes available, which one should you use?

The answer in part comes from the classic rule with soft lighting which is this. The bigger the light source (relative to the subject) the softer the light produced. In other words bigger softboxes give softer light and as long as your softbox is close to your subject that holds true. To test it out I got my 28″ Parapop softbox from Adorama, a medium sized softbox and borrowed a giant 7′ Westcott umbrella softbox.

You can see this in action in the three photos above. In each shot the distance from light to the model was 1 meter and the light was metered at f/8. Notice how the shadows blend in with the highlights as the softbox size increases and that’s soft light in action.

Now remember I said the softness of light is also relative to the subject size. Well here’s what happens if you zoom out and shoot a larger, full length portrait. Once again the distance and settings are the same in all shots.

Look at the shadow behind the model. With the small and medium sized softboxes you’ll see a sharper, harder edge to the shadow then the big softbox. You’ll also see that the smaller softbox gives a smaller spread of light compared to the more even illumination of the large softbox.

So if you want to shoot full length portraits with soft light then an oversized softbox is one answer but it has another use to. Unless you want to spend time in Photoshop cloning out the light you’ll need to back it up. Moving the light away from the subject makes it that much smaller and therefore harder. Oversized softboxes allow you to get soft light without the source being in the scene.

Take a look at this video where I cover all of this and more.

Of course there are a few downsizes to large softboxes, one of which is the lack of directional control. In the video above I add some control using Photoshop but in the next video I’ll add it to the light.

Gear used in this video