1. Flash photography
Photography 2
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2. Why flash? Flash allows you to take a “slice of daylight” with you.
On camera flash is never the “best” light, but sometimes it is the only solution.
It can be a creative tool in the right hands.
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3. Flash synchronization
On SLRs the shutter opens and closes in stages. The flash must fire during the “window of opportunity.”
The full opening of the first curtain, triggers the flash.
When the shutter speed is too fast, the bottom curtain begins closing before the top curtain is fully open.
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4. Flash synchronization
Here is an example of an unsynchronized flash photo. Notice that ½ of the picture is cut-off.
That is because the curtain is opening too fast to sync with the burst.
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5. Flash synchronization
Most film SLR’s sync at 1/125 or 1/60,  or X (or slower—more about that later)
Most DSLR’s sync up to 1/180 but some go up to 1/250. There are some variations in this. Check your manual or online to find out what your maximum sync speed is for your particular camera.
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6. Aperture for flash
So, picking a safe shutter speed for your camera is easy. You want to use the sync speed (or slower) but how do you calculate aperture?
Use the exposure calculator on the back or top of your flash unit. Some more advanced units have the calc. in an LED readout. If you have a dedicated flash (pairs with your camera, the adjustments can be automatic.)
Whether your flash is auto or not, every photographer should learn how to manually set up a flash photo.
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7. Set ISO The calculator must first be set for the ISO you are using.
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8. Camera to subject distance
Determine the distance from your subject to your flash/camera by estimation or using the distance index on camera’s focusing ring.
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9. Aperture for flash
Use the calculator on the back of your flash to determine the proper aperture. For example, at 100 ISO, a distance of 15 feet would require an f-stop between 4 and 5.6
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10. Automatic exposure calc.
The fronts of some flash units feature an “eye” that measures the flash to subject distance and adjusts the brightness or duration of the flash accordingly.
You still need to set an aperture, but the flash unit will adjust accurately within a range of distances.
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11. Automatic exposure calc.
On the blue setting, set your aperture to whatever number is lined up with the blue dot and you can use the flash between 3-13 feet without changing the f-stop.
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12. Automatic exposure calc.
On the red setting, set your aperture to whatever number is lined up with the red dot and you can use the flash between 7-28 feet without changing the f-stop. This is an approximation and makes calculating flash brightness easier on the fly, but it does not guarantee great flash pictures.
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13. Getting better results
Most people use flash to replace the existing light in a picture (ex: a picture taken in a dark room)
Skilled amateurs and pros use flash to augment (rather than replace) available light.
Let’s look at some common flash problems and their solutions.
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14. Slow sync flash
The sync speed is the fastest SAFE shutter speed to use with a flash but it often produces over lit subjects with very dark backgrounds.
Slow sync is intentionally using a slower speed to gather more ambient (existing) light to balance out the flash burst. With this technique the flash provides a “bump” of light rather than the sole light.
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15. Slow sync flash
Slow sync flash when combined with a very slow shutter speed (1 to 1/15) or even with bulb (B) can produce some interesting and even stunning results.
Movement in the picture will blur while the still subject will be “frozen” by the flash of light. Very cool when used right. Not so much when not.
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16. Bounce Flash
Bounce flash is a technique used to make artificial light look more like ambient light by reflecting it off a ceiling, wall or other reflector.
One key factor in bounce is remembering how it affects the distance from flash to subject when deciding what aperture to use. Distance is measured by this formula
Flash to reflective surface + Surface to subject = actual distance
Then always subtract 1-2 f-stops for absorption and fall off (not all the light rays will perfectly bounce to your subject)
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17. Bounce Flash
When used well, bounce should look almost like natural light. If reflected off ceiling it appears as overhead light. If reflected off wall, it often looks like side-window light.
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18. Combine slow sync
Combine slow sync with other methods (bounce, etc) to get flash pictures without the tell tale flash leftovers (glare, red eye, harsh back shadow, etc.)
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19. Fill flash Fill flash fills in a subject’s shadow area with light.
Bright sun can produce high contrast shadows. The brightness ratio between shadow areas and highlights may be too great to capture adequate detail in both areas.
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20. How to set fill flash
First, your shutter speed must be set to its “X” (sync) setting.
Use the light meter to calculate a proper exposure without the flash.
Determine your camera-to-subject distance and check the flash for the proper aperture setting.
This is the distance for normal flash, not fill flash. Normal flash would be too bright. You must now adjust the light so the brightness is cut.
Remember: adjust the flash brightness and not the camera’s exposure.
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21. Methods for adjusting brightness
These methods are listed from easiest to more difficult, but easier isn’t always better.
High end flashes come with an adjustable power feature. Cut the intensity of the flash by ½ or more.
Buy some warming gels (amber color cellophane) and tape over your flash. Typically, an amber gel can cut your flash power by ½ . Experiment.
Use a commercially available bounce card. Click
Tape a tissue or white napkin (double thickness) over your flash. There’s an added benefit of a softer light. Also bubble wrap works.
A DIY bounce card out of craft foam or card stock (we may try this in class if I can afford the foam)
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22. More methods
Buy a Prolight Dome. These are cool and not too expensive. Or do a DIY
Move the flash further or closer to your subject than the distance indicated in order to obtain proper fill flash exposure for the selected aperture.
If this distance is the same as the shooting distance, the flash can remain on the camera.
Long sync extension cords will help you achieve distance. Also you can try bouncing or defusing the light. Also move to the recommended distance and use a zoom lens with your camera to get closer to subject.
These external sync cords are fairly costly for DSLR cameras so another option may be more practical
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23. Assignment Check out a flash from me
Use techniques listed here to take the following shots
Unsynchronized flash photo
2 Synchronized flash photos with direct, frontal flash—properly exposed.
Bounce flash off ceiling
Bounce flash off wall
Fill flash calculated properly
Fill flash with DIY bounce card, dome, or some other kind of diffusion
Slow sync flash
Slow sync flash with motion
You will need to take several of each to insure getting good ones. Remember, fill flash is experimental until you really understand your flash and camera. There are many variables.
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24. Bounce card
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25. Prolight Dome
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26. Bounce off wall
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