Two major accessories we use with Fresnels are "top hats" and "barn doors. Note the top hat to your right. This accessory slides onto the instrument in the gel frame slots thus extending the barrel of the instrument. This means the spread of the light is narrowed dramatically allowing for more precise aiming of the light.
The barn doors, to your left, also fits into the gel frame slots, but their function is a bit different than top hats. In effect, barn doors provide a Fresnel shutters like a leko has. This allows us to shape the light, to some degree, although the degree of control is far from the level of control we get from lekos.
