Dumb lighting question

[Johnboy2978]

Ok folks I have a black background and a white background. I have 2 AB 800 strobes and in the past, I generally used my black BG the majority of the time b/c I could never adequately pull off the white BG. It always came out muddy, looked like shiat on a cracker and generally just ticked me off. I am making it my task to once and for all get this figured out, b/c I know it's not that big of a deal. Now I'm finally getting some decent high key results w/ the white BG as I'm using one of my AB bare bulb, no reflector and 2 stops higher than the main light which I'm using w/ my giant octobox. (My next purchase will be a Sekonic 358 Light meter by the way).

Anyway, I'm finally in the ball park of what I want to do. Stupid question... how do you hide/position the strobe in the BG so you don't have to clone it out. I'm in a pretty tight space and if I move it to the side and try to light it on an angle, it ends up lighting the subject as well which I don't want.

 

[Derrel]

Lighting a background from the side is relatively easy with the right reflector system. With a Speedotron light, it's trivial to position one, or two lights off to the side of the paper and fit them with either 50 degree or 65 degree 11.5 inch reflectors, thus perfectly illuminating a 9 foot wide seamless in a typical shooting environment. I'm not sure what Alien Bees has to offer in terms of a reflector that spreads the beam in the 50 to 65 degree range; do you have a reflector than can be fitted with a set of barn doors, to prevent spill light from hitting the subject?? Or, could you position a large gobo (which comes from the phrase a "go-between") in between the light and the subject--something like a free-standing reflector panel or a V-card, or some other type of light blocker? That will throw light onto the backdrop, but will keep any bounce or stray light from coming back toward the subject or camera area.

Do you have a boom arm, from which you can aim the light from overhead, at the backdrop? That's another way you could approach it.

 

[Big Mike]

For the background to be truly white, it has to have at least as much as the subject...or more. But since light falls off over distance, any light that is lighting the front of the subject, will fall off as it gets to the background...leaving you with a muddy looking background. The key to a white background, is to light is separately from the subject.

If you have enough lights, the easiest way is probably to cross light the BG with two lights. That way, even a wrinkly backdrop can be lit pretty evenly, giving you a nice white background.

It can still be done with a single light, but it really helps if you have a smooth backdrop because any wrinkles will cause shadows when lit with a single light.

I have a short background stand and the AB 'shovel' reflector. It works well enough, but only when shooting upper body shots, or maybe a group shot where I can hid the light behind them. With a single (small) subject, I don't use it.

 

[Johnboy2978]

I suppose I'll need to either get a set of honeycomb filters along w/ a barn door system for future use at some point then. I also need to get a background stand as my tripod is serving this purpose currently since I didn't have one handy.

 

[Big Mike]

I have the honeycomb grids and they are a great accessory. I have used them on the background lights, and while they do help to keep the light from spilling onto the subject, they do make it hard to get a solid background, unless you have a lot of space to shoot in (in which case, you probably wouldn't need them).

What they are good for, is creating a spot of light, with a nice gradient falling off.

I don't have barn doors for my AB lights, but I've got some other strobes with barn doors, and they are great. They would more useful in this situation, than the grids, IMO.

 

[Johnboy2978]

Well, just using it bare bulb w/o any reflector or modifier gives me almost an entire 10' x probably 7' area that is properly exposed for high key, and that it with it placed about 1.5' from the BG. It does create the problem of having to go back and clone out the strobe. It is much easier, I must say, than trying to fix a white background which wasn't properly exposed in the first place though.