My purpose for introducing these concise articles on the subject of light is to encourage the emerging or established photographer to use the adaptable natural tool that is light in order to obtain a desired effect with confidence.
Initially, I have purposely avoided delving deeply into the complexities of optical physics hopefully, without detriment to the value of the information. Also, I have omitted using lighting set up diagrams frequently featured in books which are, in the writers’ opinion of questionable good use.
More importantly, I hope to stimulate enthusiasm to develop the art of seeing a subject in an artistic light and consequently appreciate and enjoy the varied possibilities offered.
Section One – Ambient Light
All light, visual or not travels in waves of varying length. Ambient light, in relation to the artist is that light that is natural – around. This as with all light, can be refracted or broken up, reflected or bent and comprises any colour of the spectrum.
Size of Light Matters
The most important decision when determining the lighting for a photograph is the effective size of the light source. It affects highlights, shadow, modeling and often the type of reflection. is an important characteristic, a light source rays that strikes the subject matter at or near the same angle will give a high contrast; whereas, a low contrast light is that which is scattered from a variety of angles. A bright sunny day is an example of an apparent small high contrast light; an overcast day will produce an apparent large low contrast light. The easiest way to determine the light contrast is by shadows; clearly defined shadows are of high contrast from an apparent small light source, an apparent large light source has less defined shadow detail with low contrast.
An apparent small light source produces hard contrast whereas; an apparent large light source produces a soft contrast.
Light Matters – Group Angles
The effectiveness of the ambient, as with all other lighting, is determined by the angle, we can alter the reflections, contrast and modeling to suite by changing the angles of light, reflector or camera. These angles I refer to as the group angles. It is these groups that will determine where we should place our camera light or reflector. The angle group principle is the basis of lighting in fine art and photography; and is based on the law of physics that artists have followed through history; they cannot be changed by fad or fashion. Well crafted work comes with meticulous preparation, attention to detail and fine tuning.
The type of tools available to the artist or photographer is of some consequence. It is essential that they are adequate, well maintained in good working order. It is equally important that the artist or photographer is familiar with his equipment. Naturally, a seasoned photographer would choose a camera that is best suited to the work in hand. Hence; an architectural photographer would opt for a camera with full movements to make corrections to the screen image before making the exposure.
Light Matters – Filters
Should it be necessary we are able to control the light reaching the film by the use of colour correction filters. We can correct or alter colour by using sheets of cellulose acetate by projection or reflection so placed to intercept the light source. Additionally, we can use filters to compensate, with precision for any colour correction to film necessary by using filters on the camera in various ways. They are manufactured in optical glass or acetate in the three additive and three subtractive primary colours: subtractive primaries: cyan, magenta and yellow; or additive primary colours: red, green and blue. It is a matter of preference which you use. They are available in variable densities and need an increase of exposure from a third to two thirds.
Polarizing filters are very useful tools and made for use on or off the camera. Light waves vibrate in all directions perpendicular to the path of light. On reaching such as glass water or other reflecting surfaces at an angle of 30 and 40 degrees the light will become polarized which cannot be detected by our eyes without a polarizing filter. Such filter will not have any effect on light that is not polarized.
We can test for polarization by rotating the filter on or off the camera. The filter has no effect when photographing towards or directly away from the sun. There are times when we desire the effects of reflected light on surfaces, but only too often the polarized reflection cause problems with colour, density and definition. Again, this filter requires an increase of exposure of about one stop regardless of the filter rotation, they also very slightly change colour rendition.
It is worth experimenting with such filters effects as some cameras with built in metering will not give correct exposures and can also effect auto focusing.
Advantages of Ambient Light
Should I be given a choice of light to use for a particular project, given that it is one that will suite the subject, I would choose ambient even with all its complexity.
Natural light can suite any subject given the correct handling. Often the landscape artist or photographer has a limited choice, being obliged to use the existing light conditions or wait for hours, perhaps days for the suitable light. For these artist or photographers patience is a primary requisite if they are to satisfactorily complete their project.
Problems With Ambient Light
It would not be practical nor desirable for any photographer to rely on ambient light alone. Although it is the much preferred light for many subjects it does have limitations.
Through the ages artist have worked with the restriction of having to complete their work while the light was correct for the subject. The ambient light photographer is in a similar situation; he is constrained to use a shutter speed that will capture movement whilst matching it with an aperture setting that will provide the necessary depth of field.
Nevertheless, due to the recent advances in technology the ambient photographers of today are more able to overcome many of the restriction of their predecessors.
Matters of Colour Cast
Many an otherwise good picture had been ruined by a cast of an unwanted colour.
This problem can be avoided mostly by paying particular attention to surrounds that are likely to cause such reflections. These unwanted casts can be from any source nearby with bright strong colours being the most intrusive. I am now in the habit of donning a white boiler suite to prevent any cast from my clothing ruining my picture.
Matters – Subjective
In recent years it has become the de rigueur to render false over saturated colour in photography. It is now considered acceptable or even encouraged in the commercial advertising and fashion business which, has always relied on fashion or fads, but it quite often has little merit as art.
Over saturated pictures which bear little resemblance to reality are often considered tacky by the more discerning, but nevertheless sell well satisfying the whims of the plebby.
A well crafted black and white film image has maintained the artistic slot that it has held from the days of the early pioneers. It is encouraging for film enthusiast to discover that the digital geeks are now able to program their work to look like their images were captured on film!