Rangefinder Magazine
March 2006

Click Here for printable version of this article.

Rainy Day Portraits Dave Montizambert
 

Photo no. 5

What would you do if a client asked for a sunny outdoor portrait, but the weather was not cooperating? Since I am located in a wet climate (Vancouver, BC, is a rainforest), this situation has become routine. One such project was a portrait that was to have a light, airy, sunny look; unfortunately, it was needed during the rainy season. Waiting for the weather to break could take weeks, so I employed some trickery called “Simulated Sunlight” to get the shot.

Photo no. 1.	Photo no. 2.
Photo no. 3.	Photo no. 4.

Simulated Sunlight/Mixed Lighting

Photo no. 1. Models Michelle and Shelby are lit from overhead by an overcast sky (diagram no. 6)

Photo no. 2. By altering shutter speed, the image, as shot in ambient light, is underexposed by one to two f-stops. A camera flash, held off-camera and positioned behind the subjects, adds bright rim lighting that mimics the look of sunlight coming from behind (diagram no. 7)

Photo no. 3. A 6½ x6½ -foot PVC frame with white nylon stretched over it is placed camera-left of the subjects. This panel reflects light from the off-camera flash back onto the front of the subjects (see diagram no. 8).

Photo no. 4. To create a warm, sunny feel, a Wratten 81D warming filter can be used (for film shooting). If metering with a handheld meter, I would suggest simplifying things by subtracting the filter’s filter factor (i.e. the reduction of light) from the light meter’s ISO setting before starting the shoot.

If you are shooting digitally, shoot normal white balance for the scene, and then warm the image up in Photoshop using a Photoshop filter or one of the nik Multimedia Color Efex Pro plug-in warming filters like Sunshine or Skylight.

Photo no. 5 (opposite page). Overexpose the image slightly for a light, airy feel. If shooting film, open up the aperture an extra stop (from f/5.6 to f/4 in this case). If shooting digital, expose the image correctly to ensure good highlights, then adjust the exposure settings in Adobe Camera Raw or your camera’s processing software.

Shutter Speed

When using flash as a main light outdoors, shadow contrast can be controlled by altering the camera’s shutter speed to control the amount of ambient light recorded from the overcast sky, thus creating a lighter or darker shadow. On overcast days, as in the image of Michelle and Shelby, or in shaded areas outdoors on sunny days, flash can be used as a main light. Capturing the burst of light from a flash or strobe is more dependent upon aperture than shutter speed. This leaves the shutter speed free to control shadow contrast.

Diagram 6

In the vernacular, this technique is called a “Pop and Drag” technique as well as a mixedlighting technique. The camera shutter opens and the strobe fires, lighting the subject’s main side. The shutter remains open long enough to burn in the open sky ambient light.

By adjusting the shutter speed, it is possible to dial in any shadow brightness. For the Simulated Sunlight image, f/4 to f/5.6 was required for depth of field. At f/5.6 the ambient light read 1/60 second. A camera setting of 1/60 at f/5.6 would correctly expose the subjects with open sky lighting. Not wanting this, but instead wanting the ambient light as fill lighting, I set the shutter speed in image 3 (page 17) at 1/125 for a –1 fill (incident meter reading) and in image 5 (page 16) at 1/250 for a –2 fill. The faster the shutter speed, the higher the shadow contrast (and the darker the shadows).

Obviously, the ambient light has some effect on the main-lit side, so for a correct exposure it should be factored in. With a –1 fill, the open sky will add half as much brightness onto the main-lit side, so for a correct exposure f/5.6 would become f/5.6 and a half. For a –2 ambient fill, the correct exposure would become f/5.6 and a quarter.

Diagram 7

Changing shutter speed and aperture got you mixed up? Set your flash or strobe lighting with your aperture, set your shadow brightness with your shutter speed relative to the preset aperture setting. This shutter speed mainly controls the ratio of lighting between the strobe and the ambient light.

To recap, I take an incident meter reading of the main light (the white nylon material that is reflecting the rear strobe light on to the front of the subjects). I set my camera to this aperture, typically around f/4 to f/8 at ISO 400 with the strobe positioned 8–16 feet behind the subject. I take an incident meter reading of the ambient light. I turn the meter’s shutter speed dial until I find the shutter speed that corresponds to the predetermined aperture. I underexpose the ambient light by one to two stops by setting a shorter shutter speed than what the incident meter asks for. Then I start shooting.

Diagram 8

Simulated Sunlight Setup Tips:

On-camera flash units make great inexpensive, portable, selfcontained light sources (particularly the more powerful ones with manual power settings). However, they require some way of being triggered when off-camera at a distance. Radio slaves, which consist of a transmitter that plugs into your camera’s PC outlet and a receiver that the flash plugs into, are the best solution. Unfortunately they are also the most expensive solution. PC extension cords provide a much cheaper but more finicky alternative. Up to three cords can be joined together to put the flash origin up to 45 feet away from the camera.

Some cameras and flash do not have a PC outlet, they only have hot-shoes to trigger the flash. There is, however, an adapter/attachment for both camera and flash hot-shoes that allows you to plug in PC cords.

This Simulated Sunlight technique does not always work well for full-length shots. Often you will see the subject placed in a puddle of light from the flash, thus ruining the sunlight illusion. However, a really low camera angle like the one I chose for these shots creates a totally believable look. A low angle will compress the large, bright, flash-lit foreground/ background area into a thin line under the subject. To get this low angle I set the camera about six inches off the ground. Since I am down so low, I move far away from the subject so that the camera angle looking up at the subject is not too severe. To make the subject fill the frame at this longer distance, I use a long lens, or I crop in on the image afterwards.

Since on-camera flash units are not very powerful compared to ambient outdoor light from open sky, I generally find areas outdoors that have natural objects to block some of the open sky lighting. For instance, positioning your subject at the edge of a canopy of trees to block out some of the skylight works really well. It is important that the ratio between the flash and the ambient light is not too ridiculous. If so, it leads to extreme shutter speeds that exceed the camera’s flash sync speed limits, (usually 1/120th to 1/250th on modern SLR cameras).

One more recap: When outdoors, if the main light is flash, then a faster shutter speed creates higher shadow contrast; a slower shutter speed creates lower shadow contrast.

See Dave Montizambert’s program, “Controlling the Burn,” at WPPI 2006 in Las Vegas. His program will be held on Monday, April 10, in BALLY’s in Las Vegas Rooms 5–7 from 7:30–9:30 p.m.