Precision optics made possible because of the low diffuse reflectance. The only surface that applies to the SBCS principle for the highest possible total reflector efficiency.
Hammered reflectors always have multiple reflections, the smaller and more compact the reflector the more multiple reflections the more reflectance losses.
An average of at least 3 multiple reflections (equals 18% reflectance loss) is common for most compact horticultural reflectors.
Specular reflectors show a dirty surface very quickly so action can be taken in an early stage to prevent the dirt from burning into the surface.
With a hammered surface burned in dirt is very hard to see and cleaning will also be very difficult as not impossible because of the hammered texture.
Dust is easy to remove but dirt that cannot be removed by a dry microfiber cloth. It’s very hard to remove because of the dimpled structure, cleaning the reflector by hand is a hard job, mechanical cleaning is the only way to clean a hammered textured reflector properly.