Two main lights with BLACK background

I really love ZA's lighting tutorial here. http://www.zarias.com/​?p=101
Since I have a BLACK muslin backdrop, his superb white background tip doesn't really work for me. I can't light up my pure black ground, can I? Also, he stated that the minimum 3 lights are always the best choice. I assume because he uses two light to evenly light the background alone and use only one light (or more) to take care of the main subject.

Now I have two 750W light with a big blackdrop. I have a big softbox with a few umbrellas as well. If necessary, I can throw in a 580II. I understand with the black ground, it is important to separate the background and the main subject. I seriously have no idea how to make the separate with 2 strong lights. I really like Zaras' photo (the girl with the red flower scarf). Here is what he wrote.

"For the image above she was about 15 to 16 feet away from the BG(WHITE). I had a big softbox pointing just in front of her. Enough for the feathered edge to light her. Then I had a second light add a bit of a side light for separation making sure that the side light did not hit the background. "

However, he didn't mention where he pointed the 2nd light to create the separation? And at what power ratio vs the main light? It should be on the side, doesn't it?

I would like to hear anybody's experience with BLACK background. Unfortunately, I don't have any grid or beautyfish if they make the lighting better.

Thank you for sharing and discussing in advance.

Best thing I know to do with black bg is double gel a light on it, which is a nice effect.

Why not spend the sixty bucks for a roll of white seamless? It's what you need to do what you want, which you already know.

Transferring white seamless is a pain in the axx. Plus I have no space to set a nice studio like Zack has... I do shot on location...

Well, with black BG, one thing to look for is not letting the shadow side completely disappear in the BG. With 2 lights, I would use cross lighting. Softbox as main light in front, the second light as a kicker, at the opposite side of the main and slightly behind the subject. I could raise the kicker high and double it as hair light

The subject can be lit from the broad or short side. When using broad lighting, adjust and position the kicker carefully so it would not create hot spots or unwanted shadows.

You could also use the 580 for fill or use a reflector.

You can also use 1 light as main, fill with foamcore or other reflector and use your 2nd light as bg ligh, pointed at bg or you can use beind the subject pointed at the subject.

Thanks to you all. Is there any valid point to use my 580 to light the black BG? In my mind 1. 580 has much less power than my main/hair lights. 2. Black BG with light is still black... it may not be that helpful to separate subject from BG unless I cast some color on it... Well, Zack stated that the BG lighting should be stronger than light on the main subject. I wonder if it only applies to WHITE BG.

It is my own little theory, could be absolutely wrong. Thank you for enlightening me.

When using a black background you want to do 2 things. One is to make sure that none of the light from your subject area is contaminating the background, and the other is to create some separation so that the hair or dark clothing has some contrast against the background. This can be done with a background light (assuming you want an effect rather than pure black) or with a hair, accent or edge light. 2 lights works very nicely for rendering black backgrounds, while lighting the subject area and creating pleasing light on the subject.

You don't need a large space but you do need very directional lighting on your subject. Obviously you don't want a large fill umbrella at camera position pointing at your subject. Once you do that, the falloff from that light will lift the black background to various shades of dark to middle gray. You don't even need a grid.

Placement of the lights and power levels will determine how much light reaches the background and the relative brightness between subject area and background.

By using a hair light or accent light coming from behind or behind and to the side of the subject lets you create some contrast so that the hair or clothing don't blend in and disappear. Sometimes that's a really neat effect but most often you want to create a rim or edge light of some kind so there is some separation, even if only slight separation.

Thanks for the tip, Rob. I wonder what is the proper f/stop difference between main light and hair light from opporsite direction of main light. I am not talking about an extreme effect, but regular studio portraits to begin with.

I tried the free color gel sample along with my 580EX II for background lighting on BLACK BG. The result is absolutely disappointing. I set 1/1 power and place the 580 2 feet away in the middle of the BG. I tried zoom range from 24mm to 120mm, the coverage of the light is very limited. I also tried to get a bigger coverage by putting it away from BG (4-5feet). It has bigger coverage but doesn't have enough power to reveal the color on BG. (Still on 1/1 power setting). Maybe my main light is much powerful than BG light?? Maybe the model is too close to the BG (4-5 feet)?? Main light is 750W travelite at 3/5 power... Man... it is hard to get it work...

Do you have lighmeter to measure the actual bg and main light exposures?

I have a lightmeter, but I don't have to PW trigger on it. I couldn't timely press the meter and PW trigger at same time on both hands.... Any trick for me to do that?

Also I try to understand how the lightmeter works at studio setting. The meter I have L358 has an ISO setting, then can measure between Aperture and shutter speed. I assume the shutter speed is not a factor at studio setter as the ambient light can be ignored at the strobe's presence. So if I set ISO=100 and shutter speed 1/250, the reads of aperture shall only be adjusted based on the power on the strobe and the distance between strobe and subject. It shall have no point to adjust shutter speed to obtain the different aperture reads. Am I correct?

lightmeter is a must. one thing about muslin i hate is wrinkles. coloring black muslin with gel is tricky but it worths trying.
you have nice meter. it should work wired and wireless. and you can ask someone to hold meter and trigger lights yourself. i have old minolta meter and its very easy tool.

set iso 100 (camera and meter)
set sh/s at both lets say 1/125s
set both f/8
set front light and fire it somehow and read your meter (locate it carefully as in meters' manual. accordingly adjust power of front light. it'd show in gn or f/stops.
the same for back light and so on.
its fun

Galaxy99 wrote in post #6807469
Thanks for the tip, Rob. I wonder what is the proper f/stop difference between main light and hair light from opporsite direction of main light. I am not talking about an extreme effect, but regular studio portraits to begin with.

There is no 'proper' difference. It depends on the effect desired, the color of the subject's hair, the area of coverage, directionality of the light source.

Common settings are anything from having the hair light metering the same as the main light to 2 stops under but there is no rule. Find the settings that give you pleasing results, that act as separation or accents in the way you want, and make sure that you're not blowing highlights or clipping. Be especially careful of blonde hair that is already bright and contrasts a black background. You don't need to hit blonde hair with much light at all to get a really nice hair light.

Apparently you've never read your L358 manual. Page 16 explains how to use the meter in "Auto Reset cordless flash mode". I'd suggest you read it.

http://www.sekonic.com​/images/files/L-358.pdf

Galaxy99 wrote in post #6819688
I have a lightmeter, but I don't have to PW trigger on it. I couldn't timely press the meter and PW trigger at same time on both hands.... Any trick for me to do that?

Also I try to understand how the lightmeter works at studio setting. The meter I have L358 has an ISO setting, then can measure between Aperture and shutter speed. I assume the shutter speed is not a factor at studio setter as the ambient light can be ignored at the strobe's presence. So if I set ISO=100 and shutter speed 1/250, the reads of aperture shall only be adjusted based on the power on the strobe and the distance between strobe and subject. It shall have no point to adjust shutter speed to obtain the different aperture reads. Am I correct?

Thanks for the link, Randy. No, I never read the manual since I don't I have one as I bought it used...