The difference between studio strobes and speedlites.

This week we are going to talk about some very basic differences between studio strobes versus speedlites. First of all, lets start off by discussing what a studio strobe is and what a speedlite is. Studio strobes typically run on AC power or have a battery pack that runs on or is recharged using AC power. They are designed to be mounted on light stands and will accept a variety of modifiers. Battery powered, small flash units that are designed to be mounted on a camera, I going to refer to as speedlites. Actually, Canon calls their flash units Speedlites and Nikon calls theirs Speedlights. Other companies have their own names for their models, but essentially they work the same. Many speedlites will also run on AC power, but they are really designed for DC battery power.

Let’s look at the way a studio strobe looks and works. Below is a common studio strobe.

Studio Strobe

Studio strobes come in a variety of shapes and sizes and each brand has their own design, but for the most part they work the same way. Some are just a flash head (flash tube and modeling light) and the power supply and controls reside on another unit connected by a cord. The strobe pictured above is called a monolight, because everything is contained in one unit. Studio strobes typically have two lights on them. One is a modeling light and the other is the actual flash tube. The modeling light attempts to give you a representative view of what the light is going to look like when flash tube discharges. The flash tube itself creates the real light. The power output of a studio strobe is variable and the the degree of variability is dependent on the brand and model of the light. Studio strobes have brackets that allow them to be mounted on standard light stands.

The photo below is of a speedlite.

Speedlite.

The speedlite is considerable smaller than a studio strobe. You will notice that there is no large reflector and there is no modeling light on a speedlite. It’s flash tube is a small and, instead of circular, it’s straight. Although they can be mounted to light stands using an adapter, speedlites are designed to be mounted to your camera’s hot shoe. Speedlites usually have two types of power settings. There is a manual setting that allows you to control the flash’s output and there is usually an automatic feature. On the automatic setting (and if you are using a compatible camera) the flash and the camera communicate with each other. Based on the camera’s settings, the flash knows how much light it needs to produce to get the proper exposure.

OK, so now you may be wondering how they are differ in use. Studio strobes can be used on location with portable battery packs or using a small generator, as well as used in the studio. Because they are considerably more powerful than speedlites, they can create cool effects when used outdoors. Since they are made to be used with modifiers (umbrellas, grids, soft boxes, PLMs, etc.) you can easily change the quality and shape of the light. The downside is that they are more cumbersome and are not easily portable. If used outdoors (and especially with large modifiers), they often need to be sandbagged in windy conditions or they will be blown over.

Speedlites, on the other hand, are lightweight, small, and easy to handle. Because they are not as powerful they don’t have the reach of studio strobes. They cycle faster so you can be ready shoot another photo more quickly. Because of their size and power output they don’t work as well with modifiers. But for event photography (weddings, parties, conferences, etc) they excel beyond what you can do with studio strobes. They work well for most any dynamic environment where light stands and studio strobes are just not practical.

WARNING TECHNO-GEEK SPEAK: There is also a difference between studio strobes and speedlites that usually doesn’t get mentioned. It’s kinda technical, so bear with me. At their most elemental, all flash units work the same way. They take power from a source (AC power or a battery) store/accumuate it in an electronic component called a capacitor. When you hit the shutter, the electricity flows from the capacitor to the flash tube and you get that bright light flash and that pop noise. But there a difference between how studio strobes and speedlites achieve their variable output. Understanding this can allow you to do some neat things.

Studio strobes achieve their variable power setting changing the amount of electricity stored in the capacitor. For instance, the flash unit at half power stores half the electricity than it stores at full power. So, what can happen is this: if your turn on your studio strobe and set the power to full, the capacitor stores the maximum amount of electricity. Now, lets say you turn the power to half power before you discharge the light. The capacitor still has the full charge so if you take a photo and your camera is set to properly expose a photo at half power, you will get an over-exposed image. Some studio strobe makers have found a way to drain power from capacitor when you reduce power. Otherwise, its a good idea discharge your studio strobe whenever you reduce the power.

Speedlites work differently. They are designed to conserve battery power and to be able to cycle quicker. The way they work is to fully charge the capacitor all the time. So how do they have variable output? They change the duration of the flash itself. So, at full power, the flash duration may be 1/4000 of a second. When you set it to half power, the flash duration changes to 1/8000 of second. This means that lower power settings, the speedlite can recycle and be ready to shoot again very quickly. (These flash durations are for example only and will change or be different depending on the brand and model of your speedlite).

There’s also and other “side effect” to this behavior. It means that in a dark environment, you can create some neat effects. With such a short duration you have the effect of using an extremely high shutter speed, even if you never exceed your maximum sync speed. For instance, the photo below is of a soap bubble popping on the tip of a wood screw.

High speed flash.

If you feel like experimenting, you can create some fascinating photos playing with this technique.

Well, I got long winded this week. If you finished reading this, thanks for sticking with it and I hoped you learned something.

-Ken