Lighting102 - Lesson 1.2 Distance

Hmmm ... light has DOF (depth of field) ... sort of. I had to think about this one and mess around with the assignment set up before I started to get it.

So the objective of this exercise was to demonstrate that light has DOF and with enough light, you can turn any white wall background black. After playing with this exercise I think another way of looking at it is to consider that we are controlling the pace at which light "falls off" beyond our subject. And using that as a design choice or tool set to control our compositions.

Setting Summary

Camera: Mode @ Manual, Shutter @ 1/125th, Aperture @ f/5.6.
SB-800: Mode @ Remote, Channel 3, Group A, Zoom @ 50mm
SU-800: Mode @ Remote (not Macro), Group A set to 1/8 power on Channel 3

What I kept constant throughout the exercise was the shutter speed and the angle for the light to the subject. Otherwise distance from subject, flash output power changed. Aperture changed on the last image because I ran out of lower output settings on the flash. I tried to match the previous exposure by reducing the flash output only as I moved the flash closer to the subject.


D = distance, FP = flash power, A = aperture, S = shutter

Theoretically, it makes sense to me that what we're simulating is moving the background farther away from the subject. The distance between the subject and the light source remains the same throughout. The light power level and exposure settings remain the same. Only the distance between the background and the subject change.

However, since it can be infinitely more difficult to move the background (unless of course, you're Flo Zigfield or the like) we simulate the same principle: decrease the amount of light therefore darkening the background; decrease the distance from the light to the subject which increases the intensity of light on the subject but, produces more rapid falloff past the subject.

I think I'll do this exercise again only leave the power level of the light source the same and adjust only the aperture to accommodate the increased intensity on the subject as the light becomes closer. I'll let you know how it turns out.

i shoot nikon

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