Portrait lighting
/ lighting, photography

 

Composition – These are the basic lighting techniques you need to know for photography and film
/ composition, lighting, photography

http://www.diyphotography.net/basic-lighting-techniques-need-know-photography-film/

Amongst the basic techniques, there’s…

1- Side lighting – Literally how it sounds, lighting a subject from the side when they’re faced toward you

2- Rembrandt lighting – Here the light is at around 45 degrees over from the front of the subject, raised and pointing down at 45 degrees

3- Back lighting – Again, how it sounds, lighting a subject from behind. This can help to add drama with silouettes

4- Rim lighting – This produces a light glowing outline around your subject

5- Key light – The main light source, and it’s not necessarily always the brightest light source

6- Fill light – This is used to fill in the shadows and provide detail that would otherwise be blackness

7- Cross lighting – Using two lights placed opposite from each other to light two subjects

IES Light Profiles and editing software
/ lighting, reference

http://www.derekjenson.com/3d-blog/ies-light-profiles

 

https://ieslibrary.com/en/browse#ies

 

https://leomoon.com/store/shaders/ies-lights-pack

 

https://docs.arnoldrenderer.com/display/a5afmug/ai+photometric+light

 

IES profiles are useful for creating life-like lighting, as they can represent the physical distribution of light from any light source.

The IES format was created by the Illumination Engineering Society, and most lighting manufacturers provide IES profile for the lights they manufacture.

 

 

Arnold file

 

https://www.real-ies.com/

Composition and The Expressive Nature Of Light
/ composition, lighting, photography

http://www.huffingtonpost.com/bill-danskin/post_12457_b_10777222.html

George Sand once said “ The artist vocation is to send light into the human heart.”

Rendering – BRDF – Bidirectional reflectance distribution function
/ lighting, photography

http://en.wikipedia.org/wiki/Bidirectional_reflectance_distribution_function

The bidirectional reflectance distribution function is a four-dimensional function that defines how light is reflected at an opaque surface

http://www.cs.ucla.edu/~zhu/tutorial/An_Introduction_to_BRDF-Based_Lighting.pdf

In general, when light interacts with matter, a complicated light-matter dynamic occurs. This interaction depends on the physical characteristics of the light as well as the physical composition and characteristics of the matter.

That is, some of the incident light is reflected, some of the light is transmitted, and another portion of the light is absorbed by the medium itself.

A BRDF describes how much light is reflected when light makes contact with a certain material. Similarly, a BTDF (Bi-directional Transmission Distribution Function) describes how much light is transmitted when light makes contact with a certain material

http://www.cs.princeton.edu/~smr/cs348c-97/surveypaper.html

It is difficult to establish exactly how far one should go in elaborating the surface model. A truly complete representation of the reflective behavior of a surface might take into account such phenomena as polarization, scattering, fluorescence, and phosphorescence, all of which might vary with position on the surface. Therefore, the variables in this complete function would be:

incoming and outgoing angle incoming and outgoing wavelength incoming and outgoing polarization (both linear and circular) incoming and outgoing position (which might differ due to subsurface scattering) time delay between the incoming and outgoing light ray

Black Body color aka the Planckian Locus curve for white point eye perception
/ colour, lighting, photography, reference

http://en.wikipedia.org/wiki/Black-body_radiation

 

Black-body radiation is the type of electromagnetic radiation within or surrounding a body in thermodynamic equilibrium with its environment, or emitted by a black body (an opaque and non-reflective body) held at constant, uniform temperature. The radiation has a specific spectrum and intensity that depends only on the temperature of the body.

 

A black-body at room temperature appears black, as most of the energy it radiates is infra-red and cannot be perceived by the human eye. At higher temperatures, black bodies glow with increasing intensity and colors that range from dull red to blindingly brilliant blue-white as the temperature increases.

The Black Body Ultraviolet Catastrophe Experiment

 

In photography, color temperature describes the spectrum of light which is radiated from a “blackbody” with that surface temperature. A blackbody is an object which absorbs all incident light — neither reflecting it nor allowing it to pass through.

 

The Sun closely approximates a black-body radiator. Another rough analogue of blackbody radiation in our day to day experience might be in heating a metal or stone: these are said to become “red hot” when they attain one temperature, and then “white hot” for even higher temperatures. Similarly, black bodies at different temperatures also have varying color temperatures of “white light.”

 

Despite its name, light which may appear white does not necessarily contain an even distribution of colors across the visible spectrum.

 

Although planets and stars are neither in thermal equilibrium with their surroundings nor perfect black bodies, black-body radiation is used as a first approximation for the energy they emit. Black holes are near-perfect black bodies, and it is believed that they emit black-body radiation (called Hawking radiation), with a temperature that depends on the mass of the hole.

 

Tracing Spherical harmonics and how Weta used them in production
/ lighting, production, software

 

A way to approximate complex lighting in ultra realistic renders.

All SH lighting techniques involve replacing parts of standard lighting equations with spherical functions that have been projected into frequency space using the spherical harmonics as a basis.

http://www.cs.columbia.edu/~cs4162/slides/spherical-harmonic-lighting.pdf

 

Spherical harmonics as used at Weta Digital

https://www.fxguide.com/fxfeatured/the-science-of-spherical-harmonics-at-weta-digital/

Unity 3D resources
/ IOS, lighting, production, software

http://answers.unity3d.com/questions/12321/how-can-i-start-learning-unity-fast-list-of-tutori.html

 

If you have no previous experience with Unity, start with these six video tutorials which give a quick overview of the Unity interface and some important features http://unity3d.com/support/documentation/video/

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