Monday, November 4, 2013

Better Flash Photography

Simplify the 

...and Learn to Take More Consistent Photographs

I don't know how much the Inverse square Law comes up in the everyday Photographers conversations, but I hear Professionals talk about it and even though many pros understand what the law means to them and the way they take photo's; it still seems to bug down there own ability to explain what the purpose of this law does and how it translates to us the everyday photo guy's and doll's.

I'm going to attempt to simplify this for all of us, Pro and non-pro alike. Most of us just want to be able to create simple images with good results with little need to think about things like aperture, ISO and Shutter speed, then add in a flash and Ugggh....

 "Wait can you make another wish grandpa I need you to blow out the candles again because I didn't..." 

I didn't, those words haunt many a photographers, all because of that evil 'f'' word. 


Let's make it simple, below are a couple of charts that I created to help me keep a more consistent image and I decided to share them with you in a .Jpeg format that can be easily downloaded.

Anyone who understands the Inverse Square Law is going to find my simplified thought quite annoying. But it may help you to explain the Law to someone else.

Here are two definitions... 

Science—when a light source is moved further from a subject,  or a subject from its light source its intensity reduces by the square of its inverse. Meaning the amount of light on a subject will be the square of its inverse of 22.
Simple—Light falloff is relevant to Light distance.

This first chart is a quick reference guide I have memorize. It makes understanding the science on a little bit simpler terms; BUT ITS STILL BORING, so if you don't want boring skip ahead to the next section now, unless you are looking for a good nap, and this should be where you keep reading on. 

Just about anyone can tell the difference between two, four, eight feet and so on. Using this simple diagram has helped me to understand and quickly reference how to set up my flash to change the shadow effects of the image. It helps to avoid the ratio battle and confusion that comes from using flash and multiple flashes. 

Let's suppose I place my flash on any power level I want to and place it 2' from my subject, well we all know that it is going to be very harsh and quite unpleasant to look at in most cases: so I move it back to 4', now the same flash on the same power level with twice the distance only about 25% or 1/4 of the light will reach my subject, lets move it back even further to 8', now the same flash has only 1/16 of the light or about 6.25% of the light will fall across my subject, and even further to 16', now that's a mear 1/64 or 1.5% of the light that I had at the original 2' distance where I started. 

Using this method, which is the Inverse Square Law, any distance can be plugged in: feet, inches, yards meters, whatever your comfortable with or whatever the situation you find yourself in this will remain constant. Something so simple as moving the flash distance can change the effect of shadows in your image. Foreground or Background. 

The Easier Setup...

What I've done with this chart, based on Speedlight's (or speedlite if your a Canon photographer) manual settings I've developed a very simple chart for what Power setting to put my flash on based on how far I am from my subject. 

Camera is set at ISO 100 or 200 and shutter speed is set at 100 or 125th on shutter priority mode this lets the camera adjust the aperture. It's a great starting point and its based on doubling the distance. Helps to avoid chimping (looking at the histogram and LCD screen after every photo capture) and is much quicker than those methods. 

I do recommend that a light meter be used when possible, but that's not always the case when we don't have our gear or photographing something like Christmas, birthdays and family reunions and other holidays and such. 

My recent self portrait was done on 1/32 power at about hands distance away and in a lit room, this image acutally ended up being my last one, once I got the shot then I was done then I did what I wanted to well actually I spent more time writting my blog...

Keep shooting and as always Happy Shooting!

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