I'm thinking about using a 42"x72" shoot through panel for an upcoming full length shot. Do you think one E640 behind the panel will be sufficient to provide nice even light or do you think I should use two heads?
I guess it depends on how even you really need the light to be. If you're shooting clothing, you probably want everything spot-on from head to toe, but for a portrait, maybe it doesn't matter as much. So, what kind of shoot is it?
Two will guarantee even light, but one can get you extremely close, with just a slight falloff of light (if any). I bet you could get within a third of a stop from head to toe with proper positioning of your light relative to the panel.
No problem. A 1/3 of a stop is practically imperceptible anyway, so for a bridal portrait, you can definitely use one light. You could even emphasize the falloff and use it to your advantage if you need to keep detail in a white dress while properly exposing the bride's face.
While focusing the goal of creating a large diffuse source don't loose sight of the fact that if you want the lighting pattern on the face to be as naturally flattering in your full length shots as in your H&S shots you need to have your key light at the same downward angle of around 45° relative to the face. So you'll need to elevate the panel and the light source behind it. Also consider that firing the light through the panel will bounce as much light backwards into the room creating a huge amount of "spill fill". That's a not necessarily a bad thing because it will help open the shadows, but it will not be predictable or controllable.
There are other easier ways to get flattering even lighting in a full length shot such as using butterfly lighting in front with a rim light added from the back to reveal the overall shape and create subject/background separation.
Here's a note that customer service sent me regarding the panel: With the panel frame you’ll need to use a Full Chimera Cloth and one light is plenty. This will only work well in a studio, not outdoor location. For best results a Large rectangular lightbank is ideal or a 5ft or 7ft Octaplus Lightbank.
Interesting... This is an outdoor shoot. Any idea why a panel isn't a good thing to use outdoors? Too easy to sail away?
