Core Principles:
* Direction and Angle: The placement of your single light source is PARAMOUNT. It dictates the shape, depth, and mood of your portrait.
* Light Quality (Hard vs. Soft): Hard light creates strong, defined shadows and highlights. Soft light wraps around the subject, producing more subtle transitions. The size of the light source relative to the subject determines hardness or softness.
* Distance: The distance of the light from your subject will impact the falloff of light. Moving it closer to the subject will result in a faster falloff and more dramatic shadows.
* Background: A dark background enhances the drama by allowing the light on the subject to stand out. A lighter background can be used, but it changes the feel significantly.
* Subject Pose: Consider how your subject's pose interacts with the light. Turning the face slightly towards or away from the light can drastically alter the shadows.
* Exposure: Metering and setting your camera settings (ISO, aperture, shutter speed) are crucial for a well-exposed portrait.
Steps to Achieve the Look:
1. Gear:
* Camera: DSLR, mirrorless, or even a smartphone (if it has decent manual controls).
* Lens: A portrait lens (50mm, 85mm, or something in that range) is ideal, but any lens will work. A wider aperture (e.g., f/2.8, f/1.8) will help create a shallow depth of field and isolate your subject.
* Light Source: This is your key piece. Options include:
* Speedlight/Flash: Provides a powerful, controllable burst of light. You'll likely need a trigger to fire it off-camera.
* Strobe: More powerful than a speedlight, often used in studio settings.
* Continuous Light: An LED panel or a traditional studio light. Easier to see the effect in real-time, but might not be as powerful as a flash.
* Even a bright desk lamp: Can work in a pinch, especially for experimentation.
* Light Modifier (Optional but Highly Recommended): This shapes the light.
* Softbox: Creates soft, even light. A larger softbox produces softer light.
* Umbrella: Another way to soften light.
* Reflector: Bounces light back onto the subject to fill in shadows. Can be white, silver, or gold.
* Snoot/Grid: Focuses the light into a tight beam, creating a dramatic spotlight effect.
* Light Stand: To position your light.
* Background: A dark wall, a black backdrop, or even a sheet of black fabric.
2. Setup:
* Position Your Subject: Have your subject sit or stand in front of your chosen background.
* Place the Light: This is the most important step. Experiment with different positions:
* 45-Degree Angle: Position the light at a 45-degree angle to your subject and slightly above eye level. This is a classic portrait lighting setup that creates flattering shadows.
* Side Lighting (90 Degrees): Place the light directly to the side of your subject. This creates very dramatic shadows and is often used for moody or artistic portraits. One side of the face will be brightly lit, while the other will be mostly in shadow.
* Above/Below: Placing the light directly above or below the subject can create more unusual and dramatic lighting. These positions are often less flattering but can be used for specific effects.
* Backlighting: Position the light behind the subject. This will create a silhouette effect, or you can use a reflector to bounce some light back onto the face.
* Modifier (If Using): Attach your softbox, umbrella, or other modifier to your light. Adjust the distance of the modifier from the light source to further control the softness of the light.
* Reflector (If Using): Hold a reflector opposite the light source to bounce light into the shadows and brighten them up. You can also have someone hold it for you. Adjust the angle and distance of the reflector to control the amount of fill light.
* Test Shot: Take a test shot and carefully examine the shadows and highlights. Adjust the light position, modifier, and reflector until you achieve the desired effect.
3. Camera Settings:
* ISO: Keep it as low as possible (e.g., ISO 100 or 200) to minimize noise. Increase only if needed to achieve proper exposure.
* Aperture: Choose an aperture that gives you the desired depth of field. F/2.8 or f/4 will create a shallow depth of field, blurring the background. F/8 or higher will give you more of the scene in focus.
* Shutter Speed: Adjust your shutter speed to control the overall brightness of the image. If you're using a flash, your shutter speed will typically be limited to your camera's sync speed (usually around 1/200th of a second).
* White Balance: Set your white balance to match the color temperature of your light source. If you're shooting in RAW, you can adjust the white balance in post-processing.
* Metering: Use spot metering to meter off the subject's face. Adjust exposure compensation as needed to ensure the face is properly exposed.
* Focus: Focus carefully on the subject's eyes.
4. Posing:
* Consider the Light: How does the light fall on your subject's face? Adjust their pose to emphasize the highlights and shadows.
* Angles: Have them turn their head slightly to create more interesting angles and shadows.
* Expression: The expression is key! Consider the mood you're trying to create.
5. Shooting:
* Take multiple shots: Experiment with slight variations in posing, lighting, and camera settings.
* Review and Adjust: After each shot, review the image on your camera's LCD screen and make any necessary adjustments.
6. Post-Processing (Optional but Recommended):
* Exposure Adjustments: Fine-tune the exposure, contrast, and brightness.
* Color Correction: Adjust the white balance and color temperature.
* Dodge and Burn: Subtly lighten highlights and darken shadows to enhance the dimension and drama.
* Sharpening: Add a touch of sharpening to bring out details.
* Black and White Conversion (If Desired): Converting to black and white can enhance the mood and drama of the portrait.
Tips for Specific Effects:
* Rembrandt Lighting: A classic portrait lighting technique where a small triangle of light appears on the cheek opposite the light source. To achieve this, position the light slightly to the side and above the subject's eye level.
* Hard Light Drama: Use a bare bulb flash or a small light source without a modifier to create harsh shadows. This can be very dramatic, but it's important to be mindful of how it affects the subject's features.
* Soft Light Beauty: Use a large softbox or umbrella to create soft, flattering light that minimizes wrinkles and blemishes.
* Silhouette: Position the light behind the subject and expose for the background. The subject will appear as a dark silhouette.
Experimentation is Key:
The best way to learn is to experiment. Try different light positions, modifiers, and camera settings. Pay attention to how the light affects the subject's features and the overall mood of the portrait. Don't be afraid to break the rules and try something new.
Common Problems and Solutions:
* Harsh Shadows: Use a larger light source or a light modifier to soften the light. Use a reflector to fill in the shadows.
* Too Much Light: Reduce the power of your light source, move the light farther away from the subject, or use a diffuser.
* Not Enough Light: Increase the power of your light source, move the light closer to the subject, or increase your ISO.
* Unflattering Shadows: Adjust the position of the light to create more flattering shadows.
By following these steps and experimenting with different techniques, you can create stunning one-light portraits that capture the essence of your subject. Good luck! Remember to practice and have fun! If you can share an example image of the look you're going for, I can provide even more tailored advice.