Angle of incidence

Angle of Incidence
Almost all photographs are simply a record of reflections. Unless your camera is pointed directly at a light source, like the sun or a light bulb, you're photographing light reflecting off of a surface.

Angle of Incidence
Angle of incidence is a technical term that describes the angle of light as it strikes a surface.

Angle of Incidence The angle of light hitting a surface. A basic rule of physics; the angle of incidence equals the angle of reflectance, ...

ANGLE OF INCIDENCE - Light striking a surface is called "incident light." It becomes "reflected light" when it reflects from the surface.

-Angle of incidence - when light strikes a surface it forms an angle with an imaginary line known as the :normal," which is perpendicular to the surface.

As you can see, the angle of incidence in this case is 0 degrees. That will always produce a reflection that will ruin your photos. Always!
Getting the lighting right ...

Angle of Incidence Angle between the incident ray of light and a normal drawn to the point of reflection. I.e. The angle between the optical axis of the light incident on the surface of a filter and the axis normal to this surface.

LAW OF REFLECTION-The angle of reflection is equal to the angle of incidence.

The most important thing you'll want to read up on is "angle of incidence" (do a google search to find info on it). Basically it says that; "The physical law of light states that the angle of reflection is equal to the angle of incidence.

In the center of the image frame, the light therefore strikes the sensor head on, but as we get further out from the center of the sensor the angle of incidence becomes more oblique.

Towards the corner of the frame the angle of incidence of light coming from the rear of the lens is so severely off-perpendicular that they would not pass equally through the microlenses above the sensor leading to fairly strong vignetting.

The Fresnel formula gives the specular reflectance, Rs, for an unpolarized light of intensity I0, at angle of incidence i, giving the intensity of specularly reflected beam of intensity Ir, while the refractive index of the surface specimen is m.

The law-of-the-light states: "The angle of reflection is equal to the angle of incidence." Simply: Light is reflected at the same angle it came from, but in the opposite direction. Pool players understand.

Tilting the film spreads the light over more area. In theory you might want to add more exposure as the cosine of the angle of incidence, but I've never found it to be an issue.

Specular highlight within an image should not be used for Set Whitepoint.Light rays that are highly redirected at or near the same angle of incidence to a surface. Observation at this angle allows the viewer to "see" the light source.

See also: Light, Camera, Photograph, Photography, Image