Want to know how I use LEDs as softlights? Read the proceeding blog. I cover my favorite technique there. But I always wonder how things look with harder light so when I had Noellia in the studio today I gave it a quick test. All three of the panels you can see in set up shot below are either 160 bulb LED panels (measuring about 6 by 9 inches) or my favorite light, the 183 Bulb version (complete with its own big, lead acid battery pack. That one is 90 degrees to the left of the camera position and lighting Noellia directly. I'm using the small diffusion panel in the slot of the front of the fixture to soften the light a bit. The next light is the one that appears on the far left of this photograph. It's bouncing into the diffusion panel on the opposite side of Noellia to add some needed fill light. The final small panel is the one on the far right of the photograph which is providing a back/hair light for the image. The background light is one of the 500 bulb A/C panels running at 1/2 power (two banks instead of all four).
I hated doing hard light with flash because light placement is so critical. With the LEDs I can see the effect as we build it and I can see if I've turned my model in the wrong direction or not while I'm setting up, not while I'm chimping. Might not make a difference to you but it makes all the difference in the world to me. I want to set up one shoot often (SUOSO). Not: Chimp, chimp, chimp, chimp, shoot....
What were the technical parameters? Glad you asked. We shot with a Canon 5D2, the almost never mentioned but incredibly good for the money, 100mm f2. Our ISO was 400 and the final exposure was a comfortable 1/80th of a second at f2.8. Custom white balance before shooting. No mixed light.
Funny that we have three different models of LED lights and all of them have the same color balance....
Can you do hard light with LEDs? Absolutely.