Understanding Flash - Camera Club of Eagle

 Are you tired of your the deer in the headlights flash Images?
Understanding Flash Photography
Electronic Flash Photography Can Add Light To:
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What You Want
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When You Want
Where You Want It
Think of Flash As
Your Miniature Sun
Camera Pop-up Flash
VS
Portable Electronic Flash
Almost all of today’ DSLR’s come with a pop-up flash that you can set to engage when the camera’s light meter dictates (TTL) or can fire manually. (You Set the Exposure).
 The pop-up flash has limited light output.  Tonight’s class will deal with external electronic Flash Units.
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In Example
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Portable electronic flash unit mounted on the camera’s hot shoe, or used off camera with a remote trigger.
Photographing with Available Light Is Always My First Choice It is generally easier and requires less equipment.
 However my flash is almost always with me.
 In Changing light conditions, a flash gives me the ability to add light to the person or thing I am photographing.
 In some difficult lighting situations I may bracket 3-7 shots and combine in Lightroom HDR.
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Camera set to maual mode
5 shot Bracket, HDR in Lightroom cc Camera set to maual mode
5 shot Bracket, HDR in Lightroom cc The Photographic Triangle When Using Electronic Flash
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One simple fact, everything you have learned about the Photographic Triangle still applies when using electronic flash. Two Rules For Flash Photography
Flash photography follows the same principals as manual exposure in natural light. The only difference is the addition of supplemental light from a portable miniature sun.
 With that in mind, there are two rules important to remember
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1. The Aperture controls the amount of electronic flash light allowed to expose the picture. All flash exposures are 100% dependent on the right aperture being selected and right flash to subject distance that corresponds to that aperture. And with the ability to adjust the flash power your aperture choice is virtually guaranteed.
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2. The Shutter speed controls the amount of time that any Ambient Light is allowed to expose that same picture for which you're also using a flash for.
The Inverse Square Law and
Light Falloff
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Simply put, the Inverse Square Law states that as the flash-to-subject distance Doubles, the light reaching the subject is only 25 percent of the original light that left the flash.
First & 2nd Curtain Sync up to 1/200 canon,
1/250 Nikon
DLSR Sync Settings
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First Curtain Sync
2nd Curtain Sync
High Speed Sync (HSS Canon) (Auto FP Nikon)
First Curtain Sync
First and Second Shutter Flash Sync
Second Shutter Sync
Can Provide Amazing Flash Effects
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High Speed Sync Shutter 1/250 Aperture f/8 ISO 100
Manual vs TTL Flash
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TTL works on the premise of first sending out a “preFlash”- an infrared beam or white light that strikes your intended subject, travels back to the camera, and tells your flash’s computer how much flash power is needed to create a correct exposure based on the amount of light that comes back to the camera’s meter.
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TTL makes sense if you are an Event, Wedding photographer or photojournalist. However, TTL has a difficult time reading some lighting conditions. White or black subjects may fool the light meter. IE, A black back ground and a white dress, the final white dress image may be an ugly gray.
Manual Camera Setting and
Manual Flash Setting
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Setting both the camera and electronic flash in manual mode, allow the photographer maximum control over how the subject and background are lighted.
Aperture controls the light from the flash.
Shutter controls the ambient light.
Flash is adjusted to light the subject
The flash is moved closer or farther away from the subject. (the inverse Square Law) Guide Number
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An important element is flash power, which relates to the total distance you flash light can travel. The guide number describes your flash’s total flash output. The higher the guide number the more power the flash possesses. 
The guide number is the product of the maximum flash-to-subject distance and the fnumber of the aperture that will correctly expose film or a digital sensor with the specified sensitivity.
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GN = distance × f-number Nikon
Canon Flash Distance Indicator
Steps for Shooting Manual Flash
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Find your composition
Get your ambient exposure correct through your F stop and shutter speed settings. To shoot people with a light background, In Camera Manual, set background exposure (close aperture 1 or 2 stops to darken) 
Set your flash to manual mode and set the power to 1/1
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Use a colored gel to alter the color of the flash if desired
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If you have a flash meter you can use it to find out how much light the flash is outputting. 
If you don’t have a meter, experiment by setting your flash power to 1/4 power. Make a test exposure. If the flash is too bright, lower the setting. Too dark? Raise the setting. Check your exposure with the histogram. Don’t trust the camera LCD.
Fill in available light shots by powering down your flash.
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Practice & Experment Flash is simply a supplementary tool that we add to our tool box to enhance the light in certain situations.
 When you operate with that understanding, and once you’ve mastered the manual exposure operation of your flash, you will be able to get a better flash exposure every time.
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