My first pair is a street scene on the corner of Brahms and Liszt streets (I kid you not), very close to my house. The first image was taken in bright sun a week ago
5D2, 24-105mm, 35mm, f/8, 1/180s, ISO 100
A week late on a heavily overcast day (it was snowing slightly):
5D2, 24-105mm, 32mm, f/8, 1/8s, ISO 100
The second exposure is 4.5 stops higher than the sunshine image. The detail in the shaded sections of the image such as the house is better in the overcast image, however, all detail of the tree has been lost as it is now silhouetted against the winter sky without the fill affect of the sun.
My next pair of images are of the iconic HypoVereinsBank headquarters:
5D2, 24-105mm, 102mm, f/5.6, 1/1000, ISO 100
5D2, 24-105mm, 60mm, f/8, 1/60, ISO
The change in exposure is 4 stops, very similar to the earlier pair of images. The first image was taken in fairly low level Sunlight and so the lighting is fairly uniform and not casting huge shadows, in this case the first image contains better contrast and more information about the shape of the object. The second image is very flat and amorphous.
In both cases I have processed with auto white balance, resetting the balance to daylight on the two cloudy images adds a very noticeable blue caste to the images.
Typically for portrait photography I very much prefer not to shoot in direct sunlight as the face castes very noticeable and distracting shadows. In the image in the course work, strong sunlight would have resulted in the mans hat casting a shadow that would have completely obscured any detail in his face. Fill flash can help this, but sometimes creates a very unrealistic looking affect.
I have chosen the following two photo's from my library that would have not been improved by direct sunlight
40D, 50mm, f/2.8, 1/125, ISO 100
Strong sunlight would have overwhelmed the detail of the flowers and lost the softness of this image. I may also have run into problems with a too high shutter speed requiring an ND filter.
5D2, 100mm, f/8, 1/45, ISO 400
This detailed shot of ivy growing around the trunk of a tree would have been diminished by strong light as all detail in the shadows would have been lost.
Finally here are a few photos that take advantage of flat shadowless light (no lack of that at the moment!)
5D2, 24-105mm, 105mm, f/11, 1/45, ISO 800
5D2, 24-105mm, 24mm, f/8, 1/125, ISO 400
5D2, 24-105mm, 28mm, f/8, 1/90, ISO 400
5D2, 100mm, f/5.6, 1/180, ISO 800
Each of these images gains from a lack of strong shadows, enabling the texture and structure of the objects to come through. In the case of the third image, newspaper vending machines, the colour is more striking as the rest of the image is very muted.
In the text book the most striking use of this lighting (to me) is the Flatiron building photographed by Alfred Stieglitz (#38) where the very uniform light provides an almost ghostly look to the building and suggests the coldness of a New York winter. The triptych of images in #28 by Carlton Watkins also use very uniform flat overhead light, softening the landscape and emphasizing the vastness of the scene. The striking portrait, "Migrant Mother" by Dorothea Lange, uses the flat even lighting to bring out the texture of the groups clothing and skin, but also serves to emphasize the bleakness and hopelessness of the situation. Soft even light can be very beautiful and produce fabulous skin tones examples would be any good images of babies, however, it also conveys bleakness and melancholy. I think this is because we associate this lighting with the greyness of winter and transfer that sense of cold to our interpretation of an image.