Flash Photography

TTL (Through-The-Lens) and High-Speed Sync (HSS) are two key functions for flash photography, especially when working with outdoor portraits, weddings, or dynamic lighting scenarios. Here's a breakdown of both:

TTL (Through-The-Lens)

• What it is: TTL refers to a metering system in your camera that calculates the correct flash exposure by measuring the light that passes through the lens.

• How it works: The camera measures the ambient light in the scene and then tells the flash how much power to output for a balanced exposure.

• When to use it: TTL is great for dynamic environments (like weddings), where lighting conditions change quickly. It allows you to keep shooting without manually adjusting flash power for every shot.

• Pros: Automatic adjustments, faster shooting without worrying about flash settings.

• Cons: Sometimes TTL can be inconsistent in tricky lighting, especially with backlighting or strong contrast in the scene.

High-Speed Sync (HSS)

• What it is: HSS allows you to use your flash at shutter speeds faster than the camera’s maximum sync speed (usually between 1/200 and 1/250 sec).

• How it works: Instead of one burst of light, the flash pulses rapidly to match the faster shutter speed. This enables the flash to sync even when the shutter curtain is partially open.

• When to use it: HSS is most useful when shooting outdoors with bright light, such as mid-day portraits, where you want to use a wide aperture for shallow depth of field. With normal flash sync, you'd be limited to lower shutter speeds, which could result in overexposed images in bright conditions.

• Pros: Control over depth of field in bright settings, avoiding overexposure while using flash.

• Cons: HSS reduces flash power significantly and drains the battery faster.

When to Use Both

• Weddings: TTL can be a lifesaver during a fast-paced wedding ceremony or reception. When moving between different lighting conditions, TTL ensures your flash power adjusts automatically, leaving you free to focus on composition and capturing moments.

• Outdoor portraits: HSS becomes crucial for outdoor portraits where you want to balance natural light with flash without compromising your shallow depth of field, especially when using fast lenses in bright conditions.

Combining TTL with HSS can give you flexibility in unpredictable lighting scenarios, helping maintain both proper exposure and creative control.