Batwing or wing reflector are one of the most popular choice of grow light reflector. This is mainly due to their low cost and heat dissipation. The batwing reflector however does not provide a good amount of focus.
Deep Bowl reflector similar to the batwing does not provide a good amount of light focus, however it allows for a large coverage area.
Focal reflector is the best choice when it comes to professional and commercial growers. It provides the best focus light concentration while allowing the light source to emit the highest average affective light. The focal reflector also allows for an increased light penetration which can get deep into the plant canopy. This reflector however, can be too focus and can possibly burn plants if kept too low that is why it is recommended for high ceilings.
Board reflector provide a good focus while giving growers the option of hanging closer to the plant canopy over the focal. This is recommended for growers with low ceilings. The board reflector allows for a wide spread and with its vented reflector design it helps reduce heat over your garden.
Besides type of reflector, the material of each reflector can make a difference to your light source reflectivity. Typically reflectors comes in a white material or a dimpled aluminium. The silver dimpled aluminium can come in different material which allows for growers to choose from 70-95% on the refractive index. The higher the reflectivity the better the materials hence a higher cost