TTL ACCURACY
Here’s how accurate the flashguns are during TTL metering
TL flash metering is available with virtually all dedicated flashguns that are designed for Canon cameras. Before the exposure, the flashgun fires short pulses of light that are reflected back from the subject, passed through the lens and measured by the camera. The system then calculates the duration of flash required for a ‘correct’ exposure and communicates this to the flashgun. This chart shows how accurately TTL flash metering works when using the flashguns on test – seven out of eight scored a perfect zero! Positive values mean overexposure, negative for underexposure.