1. Understanding the Goal:
* Sharp Subject: The flash freezes the subject, preventing blur even with the slow shutter speed.
* Blurred Background/Motion: The slow shutter speed allows ambient light to be captured, creating a blurred background or showing motion trails behind or around the subject.
* Proper Exposure: You need to balance the exposure of both the ambient light and the flash to achieve a pleasing result.
2. Equipment Needed:
* Camera with Manual Mode: Essential for controlling shutter speed, aperture, and ISO.
* External Flash (Speedlight): A powerful external flash is generally recommended. On-camera flash *can* work, but it's usually harsher and less controllable.
* Tripod (Strongly Recommended): Since you're using slow shutter speeds, a tripod is crucial for keeping the background (that isn't blurred on purpose) sharp, especially if you want some elements to be still. If the camera isn't steady, EVERYTHING will be blurry.
* Remote Shutter Release (Recommended): Further reduces camera shake, especially for very slow shutter speeds.
* Diffuser (Optional): A flash diffuser (softbox, umbrella, etc.) can soften the flash, providing more flattering light.
3. Camera Settings:
* Mode: Manual (M)
* ISO: Start with the lowest ISO your camera allows (usually 100 or 200). Increase if needed to brighten the background, but keep it as low as possible to avoid noise.
* Aperture: Choose an aperture based on the depth of field you want. A wider aperture (e.g., f/2.8, f/4) will create a shallower depth of field, blurring the background more. A smaller aperture (e.g., f/8, f/11) will give you more depth of field, keeping more of the scene sharp. Consider your subject and background.
* Shutter Speed: This is the key! Start with a slow shutter speed and adjust to taste.
* Starting Point: 1/30th of a second is a good starting point.
* Experiment: Try 1/15th, 1/8th, 1/4th, 1/2, or even a full second depending on the effect you want and the amount of ambient light.
* Consider Your Subject: If your subject is moving, you might need a faster shutter speed to still get a relatively sharp freeze from the flash.
* Flash Mode: Rear-Curtain Sync (also called Second-Curtain Sync or Slow Sync). *This is crucial for the motion blur to appear *behind* the subject.*
* Why Rear-Curtain Sync? With front-curtain sync (the default), the flash fires at the *beginning* of the exposure. This means the blur will appear *in front* of the sharp subject, which often looks unnatural. Rear-curtain sync fires the flash at the *end* of the exposure, so the blur trails *behind* the subject.
* Flash Power: Start with a low flash power (e.g., 1/32 or 1/64 power) and increase as needed. Adjust this carefully to avoid overexposing the subject. You may also use TTL (Through The Lens) flash mode and dial in flash exposure compensation to adjust power. However, manual flash control is generally more predictable.
* White Balance: Choose a white balance setting appropriate for the ambient light. "Auto" often works well, but consider using "Tungsten" or "Fluorescent" if you're shooting indoors with those types of lights. You can also adjust in post-processing.
* Focus: Use continuous focus (AF-C or AI Servo) if your subject is moving, and single focus (AF-S or One Shot) if they're stationary.
4. Flash Positioning and Setup:
* Off-Camera Flash (Recommended): If possible, use an off-camera flash. This allows you to control the direction and quality of light more effectively. A simple light stand and trigger system will do the trick.
* On-Camera Flash: If you must use on-camera flash, try tilting the flash head up and bouncing it off a ceiling or wall for a softer light. A diffuser attached to the flash can also help.
* Positioning: Experiment with different flash positions to see what works best. Consider:
* Side Lighting: Can create more dramatic shadows.
* Slightly Above: Can reduce harsh shadows under the chin and nose.
* Angle to Subject: Adjust the angle to control where the light falls and how much highlight/shadow you get.
5. Shooting Technique:
* Compose Your Shot: Before you start, compose your shot carefully. Consider the background and how the motion blur will affect the overall image.
* Focus on Your Subject: Ensure your subject is in focus.
* Take the Shot: Press the shutter button and hold the camera steady during the entire exposure.
* Review and Adjust: Check the results on your camera's LCD. Pay attention to:
* Sharpness of the Subject: Is the flash strong enough to freeze them?
* Motion Blur: Is the background blurring as desired? Is it distracting?
* Overall Exposure: Is the image too bright or too dark?
* Flash Power: Is the flash too strong or too weak?
* Adjust Settings: Based on your review, adjust the following:
* Shutter Speed: To control the amount of motion blur.
* Flash Power: To control the brightness of your subject.
* Aperture: To control the depth of field.
* ISO: To brighten the background if needed.
* Repeat: Keep shooting and adjusting until you achieve the desired effect.
6. Creative Considerations and Tips:
* Subject Movement: Encourage your subject to move during the exposure for more dramatic motion blur around them. Experiment with different types of movement (e.g., swirling, jumping, walking).
* Background Elements: Choose a background with interesting light sources or patterns that will create visually appealing blur.
* Panning: Try panning the camera with your subject while they move. This will keep them relatively sharp while blurring the background horizontally.
* Zooming: During the exposure, slowly zoom in or out. This creates a radial blur effect.
* Multiple Flashes: Use multiple flashes for more complex lighting setups.
* Post-Processing: You can further enhance your images in post-processing by adjusting exposure, contrast, colors, and sharpness.
Example Scenarios:
* Nighttime Street Portrait: Use slow-sync flash to capture the neon lights and motion of cars in the background while keeping your subject sharp.
* Dancing Portrait: Capture the energy of a dancer by using slow-sync flash to show their movements as streaks of light around their frozen form.
* Spinning Portrait: Have your subject spin or twirl while using slow-sync flash to create a sense of motion and dynamism.
Key Takeaways:
* Practice is key: Experiment with different settings and techniques to develop your own style.
* Rear-curtain sync is important: Use it to make the motion blur appear behind the subject.
* Balance the flash and ambient light: Adjust the flash power and shutter speed to achieve the desired exposure and effect.
* Use a tripod: To keep the non-blurred parts of the background sharp.
Dragging the shutter takes some practice, but the results can be incredibly creative and rewarding. Good luck, and have fun experimenting!