Assignments #10 Subtractive Lighting for Portraiture.

Posted: Fri Apr 14, 2006 7:58 pm

I've been waiting for this time of year for the next two assignments as both have to be shot outdoors. There should be a few temperate days ahead.

Assignment #10 is subtractive lighting for portraiture using a light subtractor (or "Gobo").

I will give fairly detailed instructions.

You will need a "Gobo" and an assistant for this assignment.

The gobo can be a large sheet of black cardboard about 36" square. A little larger is OK too. You will also need a rod to hold the gobo with. A piece of 1" x 2" x 5' furring from Home Depot is just a couple of dollars, but any 5' long rod will work. Even a broom stick can be borrowed for this. You will also need some gaffers' tape or duck tape to fasten the stick to the board.

You will need to find a location that is in "Open Shade". I'll define that. Open shade is an area where there is no direct sun light but whatever is blocking the sunlight is not overhead. Walking through the streets of Manhattan, all you will see is open shade with the exception of an hour or 2 each day at noon time. The buildings block the sun, but not from overhead.

Open shade can be found almost anywhere with the exception of a couple of hours on either side of noon. Look for it; you will find it.

Open shade has a few good things going for it. The light is soft and diffuse. The lighting ratios are well withing your camera's recording capabilities. And because there is no obvious direction to the light, you can position yourself and your subject for the most appealing background.

Open shade has one major problem. There is a direction to the light. It is strongly vertical, from the sky towards the ground. For portraits, this is a problem as you end up with shadows under the nose, chin, and brows. The eyes are usually dark and lifeless and set in deep shadows. Not very appealing.

And easy way to deal with this problem is to use a flash, however the results are not nearly as nice as subtracting the vertical direction of the light.

Attach your stick to the gobo at the shooting site, or it will be too clumsy to transport.

Pose your subject.

Have your assistant hold gobo over the head of the subject and just out of the image area. It is easier to do if the subject is seated, or if your assistant is taller than the subject. The assistant positions the gobo by holding onto the stick that is attached to the cardboard.

By subtracting the vertical direction of the light, you are left with a strongly horizontal light that is both directional and soft. The lower the gobo is to the subject's head, the more horizontally directional will be the lighting. The higher it is, the less horizontally directional will be the lighting.

Meter for the face.

The lighting effect is more easily seen in profile and semi-profile (3/4 profile) shots. Try to shoot and include at least 1 profile or 3/4 profile shot. Also shoot some full frontal shots.

For comparison, shoot one shot with and without the gobo in place so you can judge the effect.

This is one of the more attractive outdoor lighting scenarios and once you get the hang of it the results are easily repeatable and very nice.

Posted: Mon Apr 24, 2006 8:58 pm

I do not own a light subtractor or Gobo of any sort. :(

Posted: Tue Apr 25, 2006 7:48 am

KurtSchneid wrote:

I do not own a light subtractor or Gobo of any sort. :(

Make your own as described above for less than $5.00.

Posted: Tue Apr 25, 2006 8:26 am

Improvise? OK. I will participate...should be able to on Saturday as the rest of this week is supposed to be yucky outside and no real sun to deal with according to the news this morning on my drive in.

Posted: Tue Apr 25, 2006 8:39 am

You can use this technique on overcast days ANYWHERE. The overcast lighting will resemble open shade.

So if it is overcast, shoot anywhere you want. And use the light blocker to create the horizontal lighting.

Posted: Thu Apr 27, 2006 9:26 am

Sounds like a brilliant topic. I'll be back in a couple of days with the results.

Posted: Thu Apr 27, 2006 9:33 am

will this be qualified in subractive lighting? I know I already post this before and I have to shoot a new one for the assignment but I just one to get a clear idea

Posted: Thu Apr 27, 2006 10:43 am

adorski wrote:

will this be qualified in subractive lighting? I know I already post this before and I have to shoot a new one for the assignment but I just one to get a clear idea

I don't want to speak for Packard, but my guess is that in this assignment, the goal is to actually create the lighting, rather than simply take advantage of it as you have done in that excellent portrait of the guitar player.

Joined: 06 Mar 2006 Posts: 48

adorski wrote:

will this be qualified in subractive lighting? I know I already post this before and I have to shoot a new one for the assignment but I just one to get a clear idea

I don't think this can be considered for this assignment.

1. This assignment needs to be shot outdoors
2. The effect of the Gobo, as I understand it, is not to block direct light, but rather reduce existing "open shade" light. Use of the Gobo should not result in a half-lit half-shadow portrait.

Posted: Wed May 03, 2006 10:18 am

The point of this assignment is to learn a useful and versatile outdoor lighting technique.

It should be executed as described.

Joined: 03 Jan 2005 Posts: 497 Location: Atlanta, GA

This is an interesting idea. I'll admit that I've never tried it, but will certainly try to do so!