I had a client walk into my studio last month for a corporate portrait session and I could see immediately that my go-to single-strobe setup was going to fail her. Strong bone structure, darker complexion, specific wardrobe with high contrast. The setup I’d been running for weeks was going to flatten everything that made her interesting to photograph. I needed to think in terms of a system, not a single light, and I needed to think about it fast.

That problem was still sitting in the back of my head when I came across this Joel Grimes tutorial on building a strobe system from the ground up. Grimes is one of those photographers who treats lighting like engineering, and this breakdown confirmed a lot of what I’ve been arriving at through trial and error, while tightening up a few things I’d gotten sloppy about.

Why “System” Is the Word That Changes Everything

Most photographers think about strobes as individual tools. They pick up one light, learn it, then add another. Grimes frames it differently. He’s building a system, which means every light has a role and every role has a relationship to every other light. That shift in thinking matters because it changes how you problem-solve on set. You stop asking “what does this light do?” and start asking “what does this light do relative to everything else?”

The system he lays out has a clear hierarchy. Key light first, fill second, separation or background lights third. Nothing radical there. But the specifics of how he assigns power ratios and the reasoning behind those assignments is where the tutorial earns its time.

The Ratios and Why He Lands Where He Does

Grimes bases his system around a key-to-fill ratio that keeps the fill from becoming a second key. He’s running his fill at roughly half the power of the key, which keeps shadow detail readable without going flat. On a strobe system with adjustable power outputs, that typically means if your key is sitting at full or half power, your fill is two stops under.

The separation light, which he places behind the subject and aimed back toward camera, runs lower still. Its job is edge definition, not illumination. On darker clothing or hair, you might push it up slightly, but the moment it starts competing with the key in the highlights, it’s too hot.

One thing Grimes is clear about is the background light operating independently from the subject exposure. These are two separate exposure decisions. The background can be brighter than the subject, even, but it needs to be a conscious choice, not a side effect of spill from your other lights. I keep a piece of masking tape on each of my lights with the modifier type and the power setting I used on the last shoot. It sounds obsessive, but it’s the fastest way I know to return to a working starting point.

Modifier Choice Is Not a Soft Decision

Grimes doesn’t treat modifier selection as an aesthetic afterthought. A large softbox versus an octobox versus a beauty dish each produce a specific quality of light with a specific falloff rate, and that affects how your ratios actually perform. A large softbox at a given power will wrap more and reduce the visible effect of your fill because there’s already ambient fill coming from the modifier’s size. A beauty dish at the same power will be more directional and your fill ratio will read more dramatically.

The practical upshot is that you can’t just dial in a ratio and walk away. You have to meter and look. Grimes meters his lights individually before combining them, which is a habit I picked up years ago and will never give up. Meter each light alone, record the reading, then combine and meter again. If the combined reading surprises you, you know which variable to chase.

Where I’d Push Back, or at Least Push Further

Grimes is working in a controlled studio environment throughout the tutorial, and his system is optimized for that context. When I’ve taken a strobe system on location, particularly for editorial work in spaces with mixed ambient light, the ratios don’t translate directly. The ambient becomes a fifth light with its own color temperature and intensity, and suddenly your fill is fighting daylight coming through a window or a tungsten practical lamp in frame.

My workaround is to establish my ambient exposure first and then build the strobe system around it, rather than the other way around. It inverts Grimes’ studio-first workflow, but it keeps the strobes from fighting the room. The lesson his tutorial reinforced for me is that the underlying logic of the system still holds. Key, fill, separation, background. What changes is the order in which you solve for each variable.

The Single Thing to Take Back to Your Studio

Build a lighting system, not a collection of lights. Every light you add should have a defined role and a defined power relationship to the lights that were there before it.

Watch the full Joel Grimes tutorial for the visual walkthrough of his strobe placement and the on-camera demonstrations of how each light changes the image as he adds it. That visual progression is the part that’s hard to replicate in writing and the part that will make the ratios click.