Master TTL flash in minutes, it’s easier than you think

Flash photography can seem confusing at first, and it can be a challenge, particularly when the light conditions are changing constantly. But that’s where learning TTL (through the lens) can come in handy.

TTL simplifies flash settings by automatically adjusting the flash output for proper exposure every single time, making it a useful tool for many situations. In this video, John Gress explains exactly how to use TTL flash so that you always have the correct settings.

What is TTL flash?

TTL flash technology works by measuring the light that passes through the camera lens to figure out the correct flash output. This makes sure that the exposure is correct. The process begins with pre-flash evaluation, where pressing the shutter button halfway prompts the camera’s metering system to assess the ambient light. When the button is fully pressed, the flash emits a low-powered pre-flash. The camera then measures the light reflected from this pre-flash to calculate the necessary flash power. Finally, the flash fires at the adjusted power level to produce a well-exposed image.

Benefits of using TTL

TTL gives you several benefits, particularly in fast-paced shooting environments. One main advantage is its ability to automatically adjust the flash output to match changing lighting conditions. This reduces the need for constant manual adjustments. This makes TTL especially useful for weddings, events, or sessions with rapid subject movement, where both the composition and lighting are continually shifting. By adapting to the light in real-time, TTL ensures consistently well-exposed images, letting you focus more on creativity and capturing the moment.

Limitations of TTL flash

While shooting with TTL is very convenient, it does come with some drawbacks. One difficulty is how it deals with high contrasting tones. TTL is designed to average the scene’s tones to 18% gray. This can result in underexposure in bright scenes, such as a white dress on a sandy beach, or overexposure in darker scenes, like black clothing against a dark background.

Additionally, TTL can be less reliable in complex lighting situations where direct light sources, such as backlights, hair lights, or the sun, are present in the frame, often leading to inconsistent exposures.

John then walks us through setting up a multi-light set up using TTL and he shows us just how easy it is. It’s a great tool to use for many situations, and like any technology, can really make your life easier if you know how and when to use it.

Of course, it’s no substitute for understanding how to shoot flash in manual mode, which is always going to be reliable in any complex lighting situation. However, if we have these tools at our fingertips, we should definitely use them.

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