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

Teacher: Kenji TachibanaDigital Photography IDigital Photography I..

Art 115 – Light Fall-offArt 115 – Light Fall-off

and Measurementsand Measurements

Copyright © 2003 – 2009 Kenji Tachibana

Teacher: Kenji TachibanaDigital Photography IDigital Photography IArt 115: Light Fall-off and MeasurementsArt 115: Light Fall-off and Measurements

SSet Up: et Up:

The point & shoot (compact) digital is mainly The point & shoot (compact) digital is mainly designed to take a picture of a person at about 8 feet designed to take a picture of a person at about 8 feet from the camera. At that distance with the camera from the camera. At that distance with the camera held vertically, a tall person can be easily frame from held vertically, a tall person can be easily frame from head to toe with plenty of clearance at the top.head to toe with plenty of clearance at the top.Although for that purpose, the compact digital is over Although for that purpose, the compact digital is over engineered. And so is most of the low end DSLR’s engineered. And so is most of the low end DSLR’s with cheap kit lenses. But that is a story for another with cheap kit lenses. But that is a story for another day…day…


MMaking Measurements: Using Your Bodyaking Measurements: Using Your Body

Your body is an excellent tool for Your body is an excellent tool for estimating distances. If you're 6 feet tall, estimating distances. If you're 6 feet tall, your arm span is also be about 6’. your arm span is also be about 6’. For a normal person, taking two large For a normal person, taking two large steps will pace-out 6 feet. Taking three steps will pace-out 6 feet. Taking three normal size steps will pace-out about 8’, normal size steps will pace-out about 8’, the perfect snapshot distance.the perfect snapshot distance.



Spread your fingers to measure out about 8 inches.Spread your fingers to measure out about 8 inches.



While your measuring thins. Take a measurement of While your measuring thins. Take a measurement of you camera manual. This one measures out at 7 you camera manual. This one measures out at 7 inches. Many are smaller at 6 or 5 inches.inches. Many are smaller at 6 or 5 inches.


LLight Fall-Off: Predictable distances ight Fall-Off: Predictable distances

Light fall-off is a matter of physics. The same rule applies Light fall-off is a matter of physics. The same rule applies to any light source. Because of the sun’s immense to any light source. Because of the sun’s immense distance from earth, light fall-off issues become negligible distance from earth, light fall-off issues become negligible and irrelevant.and irrelevant.Each bar below represent a 1-stop light loss.Each bar below represent a 1-stop light loss. || || || || || ||

|| || || ||

2.8 2.8 4 5.64 5.6 88 1111 1616 2222 32324545 6464

I used whole stop aperture number for several reasonsI used whole stop aperture number for several reasons


AAperture Number Use: Reasons 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 Turned into feet, it becomes useful numbers for lighting purposeslighting purposes•It also makes it easy to remember and to visualizeIt also makes it easy to remember and to visualize


AAperture Number Use: 4 feet example perture Number Use: 4 feet example

2.8 2.8 44 5.6 5.6 8 11 16 22 32 45 648 11 16 22 32 45 64If the subject is at If the subject is at 44’ from the light, there is very little ’ from the light, there is very little leeway to move forward or backward. In just only 6” in leeway to move forward or backward. In just only 6” in front and 8” behind the subject, the exposure changes by front and 8” behind the subject, the exposure changes by ½ stop, which you already know is an exposure issue of ½ stop, which you already know is an exposure issue of concern.concern.



2.8 2.8 4 5.64 5.6 8 8 1111 16 16 22 32 45 6422 32 45 64If the subject is at If the subject is at 1111’’ from the light, there is much from the light, there is much more leeway to move forward or backward. There is more leeway to move forward or backward. There is at least 12”’ in front and 18” behind the subject before at least 12”’ in front and 18” behind the subject before needing to worry about exposure issues.needing to worry about exposure issues.



2.8 2.8 4 5.64 5.6 8 11 16 22 8 11 16 22 3232 4545 6464If the subject is at If the subject is at 4545’ from the light, there is plenty of ’ from the light, there is plenty of leeway to move forward or backward. There is at least leeway to move forward or backward. There is at least 5’’ in front and 8’ behind the subject before needing to 5’’ in front and 8’ behind the subject before needing to worry about exposure issues.worry about exposure issues.By the three examples, it should be clear that further the By the three examples, it should be clear that further the light source is from the subject, greater the forward and light source is from the subject, greater the forward and backward wiggle room before facing any exposure backward wiggle room before facing any exposure change issues.change issues.


SSun and Moon Light:un and Moon Light:

Neither the sun or moon light suffer from light fall-off. Neither the sun or moon light suffer from light fall-off. They are just too far away. And moon light is actually They are just too far away. And moon light is actually sunlight reflecting off of its surface.sunlight reflecting off of its surface.Reflected light segue way. Reflected light segue way.


RReflected Light: Bounce lighteflected Light: Bounce light

Most studio photographers love using reflected light. Most studio photographers love using reflected light. It can be made to look like the elegant North Light It can be made to look like the elegant North Light but without the unpredictable light level and unstable but without the unpredictable light level and unstable cool to cooler color issue.cool to cooler color issue.Although to have useful level of light, a powerful Although to have useful level of light, a powerful studio electronic flash unit must be used. That is studio electronic flash unit must be used. That is because bounce light process reduces the light level because bounce light process reduces the light level by 2 to 4 stops.by 2 to 4 stops.

Teacher: Kenji TachibanaDigital Photography IDigital Photography I

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

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