Light, diffusion, bounce, and the Lightscoop™
1. The softness of light is a result of the size of the light source.
While softboxes and similar large flash accessories can effectively change the size of a light source and thus nicely diffuse
light, a
small diffuser placed in front of the pop-up flash cannot significantly enlarge the flash's tiny light
source... so cannot soften the harshness of the light sufficiently for my needs, candid shooting and portraits. A small diffuser can aid with lighting small objects close to the camera.
2. The physics of light is that it falls off at the inverse square: Something near to the light source receives more light than something further away. The first picture of my dentist provides a good example of the inverse square law at work. He's lit, but his assistant is in the dark. Putting a small diffuser in front of the flash may soften the harshness of direct strobe somewhat but would not change the fall-off resulting from the inverse square law. With a small diffuser, people in the background would remain in the shadows.
3. Putting a diffuser in front of a pop-up flash also does not change the unnatural direction of the light (aligned with your forehead), which is another of the reasons direct flash is awful. (Some of the nicest results with the Lightscoop have come from using it to bounce off a wall — emulating window light. I'll share some of those pictures at another time.)
In any case, I've designed the Lightscoop™ to redirect the light from the tiny pop-up flash toward a ceiling or wall. The light travels from the flash to the reflective surface in the Lightscoop to the ceiling or wall in a widening cone. The ceiling itself thus effectively becomes a larger light source, reflecting light downward and outward. Redirecting the light enlarges the light source, diffuses the light, and also results in sending light toward the subject from a more natural direction. Of course, the ceiling must be light-colored and no more than 8-10 feet tall.
The pattern on the ceiling in the test images in my first posting demonstrates how much larger the effective light source has become. The drawn illustration, below, also shows the principle at work:
2. The physics of light is that it falls off at the inverse square: Something near to the light source receives more light than something further away. The first picture of my dentist provides a good example of the inverse square law at work. He's lit, but his assistant is in the dark. Putting a small diffuser in front of the flash may soften the harshness of direct strobe somewhat but would not change the fall-off resulting from the inverse square law. With a small diffuser, people in the background would remain in the shadows.
3. Putting a diffuser in front of a pop-up flash also does not change the unnatural direction of the light (aligned with your forehead), which is another of the reasons direct flash is awful. (Some of the nicest results with the Lightscoop have come from using it to bounce off a wall — emulating window light. I'll share some of those pictures at another time.)
In any case, I've designed the Lightscoop™ to redirect the light from the tiny pop-up flash toward a ceiling or wall. The light travels from the flash to the reflective surface in the Lightscoop to the ceiling or wall in a widening cone. The ceiling itself thus effectively becomes a larger light source, reflecting light downward and outward. Redirecting the light enlarges the light source, diffuses the light, and also results in sending light toward the subject from a more natural direction. Of course, the ceiling must be light-colored and no more than 8-10 feet tall.
The pattern on the ceiling in the test images in my first posting demonstrates how much larger the effective light source has become. The drawn illustration, below, also shows the principle at work:
Posted by Ken Kobre at 4/22/2007 11:04 PM 
Categories: Photo Tips, Bounce flash, Flash photography, Pop-up flash
Categories: Photo Tips, Bounce flash, Flash photography, Pop-up flash
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