TTL (Through The Lens) means the flash meters exposure automatically through the lens and sets the power for you. It's fast and convenient — ideal for weddings, events or fast-changing light.
In manual (M) mode you set the power yourself (1/1, 1/2, 1/4…). The result is perfectly consistent shot to shot — the choice of studio photographers and strobists who fully control the light.
Most modern flashes do both. For beginners we recommend a flash with TTL and HSS so you have room to grow.
HSS (high-speed sync) lets you flash above the sync speed (e.g. 1/2000s) — essential for wide apertures in bright sun.
Pick a flash for the way you shoot.
