Which softbox—28″ or 50″?

Q: ZACK, I’M LOOKING AT BUYING MY FIRST SOFTBOX. I’M DEBATING BETWEEN THE 28″ WESTCOTT APOLLO AND THE 50″ APOLLO. NOT REALLY SURE WHICH ONE TO GO WITH FIRST. I MAINLY STICK TO PORTRAITS, HIGH SCHOOL SENIORS, AND COUPLES. THOUGHTS?

A: These are different enough that some thought needs to go into this process of which one to buy.

The smaller the light source, the harder the light will be. The larger the light source, the softer the light will be. The rule of thumb when using a softbox is that the maximum working distance from the subject should be no more than twice the diagonal measurement of the face of the softbox.

Huh? Measure the diagonal dimension of the front of your softbox. The 28″ Westcott has a diagonal measurement of three feet. By this rule of thumb, the furthest you want to get that softbox from your subject is six feet. The 50″ has a diagonal measurement of five feet. You have 10 feet to work with from subject to softbox with this light.

Why does this matter? It depends on how you shoot. Shoot a lot of full-length shots? Like to add a good bit of negative space to a photo? If so, then you’d first go to the 50″ box because you can back that thang up 10 feet from your subjects and still get a good quality of light from it. Like to shoot tighter? You do more headshot to 3/4-length shots? The 28″ can work in that scenario since you are framing tighter to your subjects and the light can be closer in.

Also think about the light source you have. The further you back the light up from the subject the more power you’ll need from your light. Using a hotshoe flash in a 50″ softbox from 10 feet away? You’ll be living at full power on that light and still only get f4 or f5.6 at best. Inverse square law is a bitch. If I’m taking my 50″ to a 10-foot mark from the subject then I’m typically driving it with an Alien Bee or something more powerful than a hotshoe flash.

Now then, we’re just talking about a basic rule of thumb. Yes, you can put a 28″ box 10 feet from your subject. You can. But you will begin to lose the quality of light that you got that box for in the first place. As you move the box further from your subject it becomes a smaller light source in relationship to them. Think about moving a 50″ box to 100 feet away from your subject. It would be a pinpoint light source on them. Move it 10 inches from your subject and it’s massive on them now! A huge, soft, wrapping light source.

Another thing to think about is the spread of light from a softbox. Umbrellas and the like sort of wash an area with light. You can shoot one person or 10 people with an umbrella. A softbox is more directional than an umbrella. The smaller the softbox, the smaller the spread. I typically use the 28″ when I’m shooting one to two people. Those two people need to be close together. I’ll shoot one to four or five people with the 50″ box.

Pictured here are the two softboxes in question. They are two of my favorite modifiers. These two softboxes have been part of my regular kit of gear for nearly 10 years. They work great with both hotshoe flashes and larger strobes.

The 28″ Westcott Apollo was used here. It is just outside of the frame to camera left. It creates a beautiful soft light with more dramatic shadows, as it is smaller than the 50″. The 50″ box would wrap more light around her face and open up the shadows. Maybe you want that in a photo. At that point, you then use the 50″ instead of the 28″. :: Nikon D3 / 85mm / f1.8 @ 1/250th @ ISO 200 with a hotshoe flash in the box.

You say you’re mainly shooting seniors and couples. The 28″ will be a good starting point. The 50″ can work, as well. It would allow you to put a little more room between couples when you are posing them. You can increase the spread from the softbox by backing it away from them, but remember that rule of thumb I mentioned: You’ll only want to take the 28″ back to about six feet. Once you need to go beyond six feet then you’ll either sacrifice quality of light or you’ll jump up to the 50″ box.

You could just about toss a coin and pick one. I guess I’d suggest the 28″ to you first. Go with that and use it for six months. Get to know that light really, really well. Know what it will do and what it won’t do. After six months of shooting you’ll start to know if the 50″ is the next step you need. You’ll know this if you constantly find that you need a larger spread of light for couples, or if you always live at that six-foot range of the smaller box.

Another thing to think about is to get the 28″ box and a 60″ umbrella. The 28″ is there for tight shots and single-person compositions. The umbrella gets pulled out when you are shooting more than two people or you need a wider spread of light for the situation you are in. A good umbrella can be had for $30 or so. It’s good to have one in your bag at all times. It’s the Swiss Army knife of modifiers.

The 50″ Westcott Apollo—or “Big Mama,” as I call it—was used here. The face of the box was approximately four feet from the subject and was being powered with a Nikon SB-80DX flash that was somewhere around half power. :: Canon 5D Mk II / 24–70mm L @ 40mm / f3.2 @ 1/160th @ ISO 400.