TTL stands for "through-the-lens" and is a flash mode that meters the exposure by going through the lens to automatically adjust the lighting for you. TTL flash is a system of calculating the correct amount of light from your flash using the information from your camera via "through the lens" metering. TTL flash is excellent in scenarios where the distance between the flash and the subject changes fast, such as photographing a moving subject. TTL flash is great for beginners who are new to flash photography and could use a little help. Here are some key features of TTL flash:

• TTL flash changes the flash output automatically, so you dont have to worry about under or overexposing your shots.
• TTL flash works by using a meter to read how much ambient light is being returned to the lens. Before the flash goes off, a short flash burst measures the light and automatically adjusts the flash power.
• TTL flash is easy to use, but its difficult to customize. Because your device chooses the settings for you, its challenging to adjust the lighting from one shot to another.
• TTL flash is not perfect and has some limitations and challenges. One of the drawbacks of TTL mode is that it can be inconsistent and unpredictable.

In summary, TTL flash is a convenient and fast way to use flash, especially if you are shooting in changing light conditions or moving subjects. It is great for beginners who are new to flash photography and could use a little help. However, it has some limitations and challenges, and it can be inconsistent and unpredictable.