Assignment 4 - Applying Lighting Techniques 1

Introduction

The objective of this assignment is to use lighting techniques to bring out the physical characteristics of a single object: its shape, three dimensional form, texture and colour in about eight photographs.

I used a couple of objects for these photographs, one a sea shell similar in shape to a snail's shell which is about 6 cms long, and the other an ornate silver sea-horse shaped ornament which is larger at about 14 cms long. I was worried that the sea shell was going to be too small to fill the frame with my zoom lens (I do not have a macro lens). On the other hand, I was concerned that photos of the crude surface of the silver ornament would be rather bland and uninteresting.

The idea of using a shell as the subject was attractive as I could refer to similar exercises in a book called "Light", part of the Collins Photography Workshop series from 2000 byMichael Freeman which used a clam shell.

I decided to use artificial light for these photographs as I am doing the assignment in December in UK when daylight is short and unpredictable. I debated whether I should try to rent or buy some equipment suitable for taking small objects. However, I first tried using a desk light and other props that we have at home. I thought the results were satisfactory, so I did not try to get hold of specialist photographic lighting.

Shape

The shape of an object is best shown in silhouette and for this purpose, I posed the objects on the smooth surface of our kitchen table set up as in the following diagram. This replicates the set used for contre-jour lighting on the studio photography course at City and Islington College.

As I wanted the sea shell to fill the frame, I started using a close up lens (Hoya +2 dioptres) attached to my Nikon 18-200mm zoom lens. Whilst the photographs looked sharp on the camera's screen, the quality of the photographs was less good when viewed at 100% magnification on the computer screen. There was significant chromatic aberration around the silhouetted edges of the shell. I used the chromatic aberration correction in Lightroom, which reduced the fringing, but the edges were still slightly soft.

I therefore repeated the sequence of photographs without the close up lens. On maximum magnification, the shell filled about a quarter of the frame at the close focussing distance. My photographs are ten megapixel, so I felt that 2.5 megapixel was still ample for the purpose of this assignment. At full magnification, the photographs were still reasonably sharp and there was no significant chromatic aberration.

The two best photographs of the sea shell in silhouette are shown below.

Sea shell silhouette 1

Nikon 18-200mm at 200mm: Iso 200 f32 for 0.7 seconds

Sea shell silhouette 2

Nikon 18-200mm at 200mm: Iso 200 f32 for 0.6 seconds

Observations

I placed the shell directly on the table surface which has a slightly reflective satin varnish finish. I positioned a white mounting board on the back of a chair with a book to hold it in place. I positioned the tungsten desk lamp to illuminate the white surface as evenly as possible, directed away from the subject.

I placed the camera on a tripod looking along the table top on manual focus. I set the white balance to tungsten and took a number of photos at maximum magnification to fix the exposure settings and check the depth of field. The shell is quite spherical and I found that I needed f32 to ensure that the edges were reasonably sharp from front to back.

To minimise light reaching around the sides of the shell which would reduce contrast, I placed two cardboard lids vertically at either side of the subject just out of the frame. I reduced light reflections from the ceiling and walls onto the shell by placing books on either side and across the top of the shell. The shell was therefore inside a dark "tunnel".

The shell has small protuberances on which it could stand in various positions. Most of the photos were not visually interesting, just a dark central dark blob with bits sticking out. I liked two of the photos (shown above) for the following reasons.

• In silhouette 1, the shell is in a supine position with a diagonal stretching between the pointed top of the shell and the curved and flattened area which is standing on the table top. There is no detail or colour in the body of the shell, but I think that there is enough information that a viewer could recognize this as a shell. The shape from this viewpoint is quite abstract, but it has a certain natural elegance.
• In silhouette 2, the shell is standing in a vertical position. The right hand edge of the shell curves round in a tightening circle indicating a spiral that is not otherwise visible. There is an intersecting curve on the upper left of the shell which is the foot opening. A small area of translucence just above centre gives the viewer just enough information to detect the distinguish the two curved shapes. If this light area is not present, the picture loses visual interest.

Sea horse silhouette

Nikon 18-200mm at 105 mm: Iso 200 f16 for 1/20th second

The set for this was similar to that for the seashell, except that the light screens and cover over the object were moved back as the object is twice the size.

The side view is the most interesting silhouette for this ornament, as shown above. The edges of the silhouette are almost in the same plane and hence an aperture of f16 was sufficient to ensure that these edges were all reasonably sharp.

This is a subject with a designed shape and the action of photography is more to record and present this shape. This is a contrast to the shell, a relatively familiar object, where the photographer can make several pictures using different positions and viewpoints.