Part Four - Light

Project - The Intensity of Light

Examples of dark images -
Richard Gilligan's Arnifornia, Essex, UK has clearly been shot on a cloudy, grey day and taken close to trees / large shrubs blocking out light.  Gilligan does not appear to have attempted to alter the scene in front of him, keeping it dark for a gloomy atmosphere.  Other images in the same article, referenced below, maintain similar cloudy and some wet conditions, although this has the darkest appearance overall.
Christopher Stewart's United States of America, 2002 is taken in a room with the only lighting a table lamp close to the right edge of the frame and the glimmer of bright, outside light on the closed blinds.  The darkness and subtle lighting, apparently not contrived, keep the image simplistic and appropriate to the subject matter.

Examples of light images -
Stephen Shore's 1-8, Yuma, Arizona, September 23, 1974 has a very light appearance and would have been taken on a very bright, sunny day.  The hills in the background have a hazy appearance, aided by the strong light conditions, while adding warmth to the dull grey road and arid landscape.
Corinne Silva's Plastic Mountain I and Plastic Mountain II are also very light and taken in extremely bright conditions.  This is particularly noticeable in the second image, where the black plactic bags, perhaps a little dusty, appear quite light and there is much detail which would have been hidden with a darker exposure.

Project - The Colour of Light

The course material asked what two directions daylight normally becomes coloured.  I'm not entirely sure if this is meant literally or in terms of which direction across the colour spectrum.  Certainly changes in the colour of daylight are most apparent when the sun is low, early or late in the day.  So to answer the question, I would say east to west and west to east.
To look at it another way, you could say that colours become warmer or cooler in different kinds of daylight.

Project - Photographic Lighting

On page 161 of the course material, it asks how the portraits by Stieglitz and Weston on p.162 would look if the shadows had been lightened.  My answer is simply, ordinary.  The dark shadow areas add an element of intrigue, without which they would be rather dull.  That's not to say that every portrait should be taken in the style.  However, I think close ups such as these need some added interest.

Notes from reading Light Science & Magic (4th edition)

The subject effects light by transmission, absorption, or reflection.

Transmission -
Subjects that trasmit light allow it to pass through them, e.g. clean air and glass transmit light.  "A subject that only transmits the light cannot be seen".
At any angle other than perpeniuclar to the subject, the transmitted light is refracted.  Refraction can be photographed, whereas simple transmission cannot.

Direct & diffuse transmission -
Diffuse transmission is where the light is dispersed in many random and unpredictable directions as it passes through certain materials, e.g, white glass or thin paper.  These are translucent materials.  Transparent materials, such as clear glass, produce direct transmission.

Absorption -
Absorbed light is not seen again as visible light, and cannot be photographed.  It can only be distinguished when compared to light that is not absorbed, in the same scene.

Reflection -
Self explanatory really.
Types of reflection: diffuse reflection, direct reflection, or glare.

Diffuse reflection -
"Diffuse reflections are the same brightness regardless of the angle from which we view them.  This is because the light from the sources is reflected equally in all directions by the the surface it strikes."
NB.  Diffusing the light source does not stop diffuse reflection.  Diffuse transmission scatters the light from source, and diffuse reflection scatters the light from the subject or background.

The Inverse Square Law -
By moving the light source closer to the subject diffuse reflection gets brighter.  It is possible to calculate the change in brightness using the inverse square law.  "The inverse square law says that intensity is inversely proportional to the square of the distance."
E.g.  The same light will light a subject with an intensity four times what it would at twice the distance.
However, some subjects will not produce brighter reflections as the light moves closer to them.

Direct reflection -
"Direct reflections are a mirror image of the light source that produces them."
Also known as specular reflections.

Bibliography
Hatherley, O. (2013) Richard Gilligan - DIY. Source. Issue 73 (Winter 2013), pages 13-21
Cotton, C. (2009) The Photograph as Contemporary Art. Second edition. London, Thames & Hudson.
Shore, S. (2004) Uncommon Places. London, Thames & Hudson
Demos, T.J. (2012) Spaces of Global Capital: On the Photography of Jason Larkin and Corinne Silva. Photoworks. Issue 19, pages 6-17
Hunter, F. Biver, S. Fuqua, P.  (2012Light, Science & Magic. Fourth edition. Waltham, Focal Press.