On location at Fovitec studios shooting our next instructional video on"How To Use StudioPRO Monolights."
HOW MUCH POWER DO I REALLY NEED?
Photographers love to get really technical when talking about lighting; how to measure light output, guide numbers, falloff etc. Although that can be interesting and useful, what most people care about when buying a strobe is power, features, and, of course, the price.
UNDERSTANDING WATT SECONDS
We get a lot of questions on this topic. If you’re new to studio lighting, your first question is likely; how much power (watt seconds) do I need? It’s a really good question because the answer has the greatest impact on price and what you can photograph with your lights. To answer the question we need to understand a little more about what the heck watt seconds are. In simple terms watt seconds are the unit of measure used for power output in strobes. The maximum watts that can be output over a 1 second duration. Kind of like light bulbs in your house. The 10W bulb in the nightlight, the 60W bulb in the living room, the 100W bulb in the lamp, all with different maximum outputs.
WHAT DO THE NUMBERS MEAN?
At Fovitec.com, our StudioPRO lights, like most of the other strobes on the market, rate our strobes this way. A StudioPRO SP-400 strobe model means 400 watt seconds, a 600 in the brand name means 600 watt seconds. Alien Bee’s are one strobe company that uses a different way of rating output called true watt seconds instead of nominal watt seconds like everyone else. That means an Alien Bee’s B800 strobe is actually only 320 watt seconds. Just so you don’t get too confused when you’re shopping around.
HOW MANY F-STOPS SHOULD MY STROBES HAVE?
New photographers often think that you can just turn your camera to a desired aperture (f-stop) and a matching aperture setting on the strobe. Camera f8, turn strobe to f8, done. It doesn’t work that way. Strobes are adjusted in power increments on a dial. It does not match your camera f-stop setting of f2.8, 4, 5.6, 8, 11, 16, 22, 32, 45, 64. The reason for this is that every time you add a reflector, softbox, or umbrella to your strobe, that f-stop is changed. It's a good idea, even if your strobes come with a specific f-stop adjustment, to calibrate with your light meter (digital cameras have internal light meters, or an external handheld meter can be used).
You have two identical 400W/s strobes in the studio in the exact same position, both powered to full power. You put a reflector on one and take a shot. The light meter says f22. The other strobe you put on a softbox and it measures f11. That’s a full 2 stops less with the strobe at exactly the same power. It’s all in the modifier and distance from subject. Starting to get the picture? Every modifier, light position, tilt, turn, or ambient light makes all the difference. This is why you will need to adjust the camera settings to match the light meter.
IT WAS RECOMMENDED I GET AT LEAST A 1200 WATT STROBE?
Good advice? Not really. They’re just following what they heard through the grapevine or happened to buy themselves. Photographers like to brag about equipment. My camera is full frame, yours is only a crop sensor. It only matters if it helps or hinders the way you shoot. A 1200W/s strobe might be great for them but not be at all practical for you. You need to seriously identify what and where you typically shoot. If you shoot newborn babies and the occasional portrait, a 300W/s is plenty of power. A 600W/s or 800W/s would be way too much.
CAN I GET TOO MUCH FLASH POWER?
Yes, here’s why. Many pros have 800W/s or 1200W/s strobes but if you ask them, you’ll find that they rarely use them at more than half power. To shoot your fastest lens like your 50mm f1.8 wide open for those blurry background, cute newborn shots you’ll need flash but not too much. An 800W/s strobe turned to its lowest setting is still way too much power to shoot your lens at f1.8. You’re likely only going to get the lens to shoot at f5.6 because of all the flash power. Now you’re limited because of too much power. If you shoot on location in big dark buildings with 30-foot ceilings, then 300W/s won’t be enough. You’ll likely need 600W/s per head. So where’s the happy medium? Here’s where it lies for most customers.
300W/s - Hobbyist, Home studio, pictures of the kids, newborn babies, small product photography, groups of 2
400W/s - Home studio, portrait, larger product photography, groups of 6
600W/s - Studio, vehicles, outdoor, groups of 20
800W/s - Pro, full size studio, location sets.
Of course there are exceptions to every rule. You’ll often find professional studios with 300W/s strobes as well as 600W/s strobes depending on the shoot. At Fovitec.com our bestselling strobes are our 400W/s, which provide a great balance.
DON'T WORRY, START SHOOTING
Starting with a StudioPRO two light strobe kit is a fantastic way to start. The truth is that most photographers end up with 4 lights at some point anyway. Background, main, fill, and hair light. The nice thing is that they will all work together, so don’t stress out too much. There really isn’t a wrong decision. Get what’s right for you and forget all the noise from others and the Internet. The important thing is just to start shooting! P.S. Look for our next instructional video on "How To Use StudioPRO Monolights."