reflection: A series of incident rays and their corresponding reflected rays are depicted in the diagram below. Each ray strikes a surface with a different orientation; yet each ray reflects in accordance with the law of reflection.
States that the direction of incoming light (the
incident ray), and the direction of outgoing light reflected (the reflected
ray) make the same angle with respect to the surface normal, thus the angle of
incidence equals the angle of reflection; this is commonly stated as θi = θr.
Thermal Reflectance and
The geometrical micro fiber structure
and high diffuse reflection of ORCA Grow Film® lends
itself to be a natural insulator and exhibit a low emissivity. ORCA Grow Film® remains
highly reflective at wavelengths out past 700nm.
The emissivity of a material (usually written ε or
e) is the relative power of its surface to emit heat by radiation. It is the
ratio of energy radiated by a particular material to energy radiated by a black
body at the same temperature. It is a measure of a material's ability to radiate
absorbed energy. Emissivity is a dimensionless quantity, so it does not have
In general, the duller and blacker a material is,
the closer its emissivity is to 1. The more reflective a material is, the lower
its emissivity. Emissivity depends on factors such as temperature, emission
angle, and wavelength.
Although it is common to discuss the
"emissivity of a material", the emissivity of a material does in
general depend on its thickness. The emissivity quoted for materials are for
samples of infinite thickness (which, in practice, means samples which are
optically thick) — thinner samples of material will have reduced emissivity.
When dealing with non-black surfaces, the
deviations from ideal black body behavior are determined by both the geometrical structure and the chemical composition, and follow Kirchhoff's law of thermal radiation:
emissivity equals absorptivity (for an object in thermal equilibrium), so that
an object that does not absorb all incident light will also emit less radiation
than an ideal black body.
ORCA Grow Film® is color neutral
and has no color shift or iridescence; this means the light reflected from its
surface maintains the original color spectrum/wavelength. Hydroponic growers
now can be assured the reflected light their plants are absorbing is the
intended light spectrum being produced from their grow lamps.
UV Protected and Stable: Some reflective foils
reflect light below 400nm, a range that contains UVB rays which can be harmful
to plants and their growth.