Teacher: Kenji Tachibana Digital Photography I. Art 115 – Light Fall-off and Measurements Copyright © 2003 – 2009 Kenji Tachibana

Teacher: Kenji Tachibana Digital Photography I Art 115: Light Fall-off and Measurements S et Up: The point & shoot (compact) digital is mainly designed to take a picture of a person at about 8 feet from the camera. At that distance with the camera held vertically, a tall person can be easily frame from head to toe with plenty of clearance at the top. Although for that purpose, the compact digital is over engineered. And so is most of the low end DSLR’s with cheap kit lenses. But that is a story for another day…

Teacher: Kenji Tachibana Digital Photography I Art 115: Light Fall-off and Measurements M aking Measurements: Using Your Body Your body is an excellent tool for estimating distances. If you're 6 feet tall, your arm span is also be about 6’. For a normal person, taking two large steps will pace-out 6 feet. Taking three normal size steps will pace-out about 8’, the perfect snapshot distance.

Teacher: Kenji Tachibana Digital Photography I Art 115: Light Fall-off and Measurements M aking Measurements: Using Your Body Spread your fingers to measure out about 8 inches.

Teacher: Kenji Tachibana Digital Photography I Art 115: Light Fall-off and Measurements M aking Measurements: Using Your Body While your measuring thins. Take a measurement of you camera manual. This one measures out at 7 inches. Many are smaller at 6 or 5 inches.

Teacher: Kenji Tachibana Digital Photography I Art 115: Light Fall-off and Measurements L ight Fall-Off: Predictable distances Light fall-off is a matter of physics. The same rule applies to any light source. Because of the sun’s immense distance from earth, light fall-off issues become negligible and irrelevant. Each bar below represent a 1-stop light loss. |||||||||| |||||||||| I used whole stop aperture number for several reasons

Teacher: Kenji Tachibana Digital Photography I Art 115: Light Fall-off and Measurements A perture Number Use: Reasons It reinforces the idea that the bars are 1-stop apartIt reinforces the idea that the bars are 1-stop apart Turned into feet, it becomes useful numbers for lighting purposesTurned into feet, it becomes useful numbers for lighting purposes It also makes it easy to remember and to visualizeIt also makes it easy to remember and to visualize

Teacher: Kenji Tachibana Digital Photography I Art 115: Light Fall-off and Measurements A perture Number Use: 4 feet example If the subject is at 4’ from the light, there is very little leeway to move forward or backward. In just only 6” in front and 8” behind the subject, the exposure changes by ½ stop, which you already know is an exposure issue of concern.

Teacher: Kenji Tachibana Digital Photography I Art 115: Light Fall-off and Measurements A perture Number Use: 11 feet example If the subject is at 11’ from the light, there is much more leeway to move forward or backward. There is at least 12”’ in front and 18” behind the subject before needing to worry about exposure issues.

Teacher: Kenji Tachibana Digital Photography I Art 115: Light Fall-off and Measurements A perture Number Use: 45 feet example If the subject is at 45’ from the light, there is plenty of leeway to move forward or backward. There is at least 5’’ in front and 8’ behind the subject before needing to worry about exposure issues. By the three examples, it should be clear that further the light source is from the subject, greater the forward and backward wiggle room before facing any exposure change issues.

Teacher: Kenji Tachibana Digital Photography I Art 115: Light Fall-off and Measurements S un and Moon Light: Neither the sun or moon light suffer from light fall- off. They are just too far away. And moon light is actually sunlight reflecting off of its surface. Reflected light segue way.

Teacher: Kenji Tachibana Digital Photography I Art 115: Light Fall-off and Measurements R eflected Light: Bounce light Most studio photographers love using reflected light. It can be made to look like the elegant North Light but without the unpredictable light level and unstable cool to cooler color issue. Although to have useful level of light, a powerful studio electronic flash unit must be used. That is because bounce light process reduces the light level by 2 to 4 stops.

Teacher: Kenji Tachibana Digital Photography I x End