Digital Photography One on One: Episode 59: Inverse Square Law

In this week's episode Mark Wallace explains the Inverse Square law and how it can improve your photography.

Category:

Education

Tags:

• snapfactory
• inverse square law
• studio lighting
• flash
• photography
• Mark Wallace
• Adorama
• digital photography one on one
• camera

[kazeem2000]

Mark where can i get your new DVD on lighting i saw the clip on you tube i need to get it, I really enjoy your show on you tube good job.

[snapfactory]

@kazeem2000 studiolightingessentials (.) com

[WarrenAckary180]

Mark.. this is unreal.. Ive learnt more in 3 episodes than in 4 weeks of photography Class!

Brilliant

[oscarcll]

Imagine a sphere of radius 1 foot around the light source, and compare that to a bigger sphere of radius 2 feet. The surface area of the bigger sphere is not twice, but four times the smaller sphere (because the area is proportional to the square of the radius). So each unit area in the bigger sphere is absorbing only 1/4 of light as that in the smaller sphere. Hence the inverse square law.

[lalalaina4life]

Hey Mark, what octabox are you using in this video?

[TheYFlyer]

Excellent, excellent video. I was aware of the inverse square law however seeing your demonstrations really help clarify it. Thanks so much for doing this series and thanks to Adorama for sponsoring it.

[gfr327]

Concerning the panels shown at 6:00, why is the left side of the 1st panel darker than the right side of the last panel? The panel appears to be ~4 ft. wide, so given the image taken at 1 ft., the images taken at 8 and 16 ft. should be no brighter than the left side of the 1' image, which should be ~ 5 ft. from the light source.

[gromacs00]

This "experiment" is completely USELESS if you don't turn off the ambient lights. It doesn't look like you turned off the ambient lights. By 16ft, you are taking a photo with the lights on the ceiling instead of the softbox. This entire thing sounded like a corny infomercial TBH, you should learn how to conduct experiments properly.

[bloddynose13]

Right. area follows rules of square. If we were measuring volume we would be looking at cubed math and really make things complicated. I like it!

[global001]

@epos85 It depends on the size of the light source. If for example you use a huge Octobox as in this video & the subjects 20 feet away & close to the background the light will be soft & cause no shadows. See Marks other video Ep 64 where he demonstrates it.

[stecartmel]

as clear as mudd lol...you got that right.

[catgasoline]

Excellent and useful tip to make the best of a simple light setup

[superrobotmunkyman]

man she is so pretty

[nstarbill]

Great job, Mark! Clear, concise and wonderful examples.