Wednesday, 26 June 2013

Exercise: Concentrating light

Many techniques have been developed to concentrate light, ranging from using Fresnel lenses on a tungsten source, through to modifiers such as snoots and barn doors.  Each has a place, for example, many Hollywood style shots used barn doors to create a defined line where the light would end.  A snoot creates a spotlight effect and typically could be used as a hair light, or as an out of focus spotlight.  Just rolling up a sheet of black paper into a cone or tube as suggested in the text would suffice, though not on a tungsten lamp.

A further modifier is referred to as a grid or honeycomb.  Such a grid causes the light to go from the source in straight lines, concentrating the light even more, giving the photographer even more control over the light.

In my example I have use a commercially produced snoot which I have fitted onto the Speedlite as in this lighting diagram:

Snoot, ISO 100, f/22, 1/125 sec
This shot is purely to demonstrate the effect of using a snoot as an example of a modifier which concentrates light.  It is a rather extreme effect for use in a portrait, though this low key lighting would work better with a craggy male face.  Here the light is to the side and at 45 degrees above the subject.  Very defined shadows and an enlarged Rembrandt light; it is more of an exaggerated 45 degree pattern with a loop shadow.
Snoot + grid, ISO 100, f/22, 1/125 sec
Here I have not modified the exposure in order to demonstrate the amount of light fall-off when using a grid.  Comparing to the previous photo, it is evident that the grid is concentrating the light much more than the snoot alone.

No comments:

Post a Comment