Transcript Flash ….. Auto

Photography with Flash
Module A
Types
Features
Control
Sync speed
Dual Lighting
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Presented by:
Lester Parkes LPSNZ
New Brighton Photographic Club
www.newbrightonphotoclub.org.nz
Flash light: Types & specs
• On-camera “pop-up” or off-camera unit.
• Small & convenient package
• Very fast pulse of light
Ex: Nikon SB800 ~ 1/1,100 – 1/2,700 sec)
Flash light: Types & specs continued …
•
Directional light pattern
- “harsh light” with shadows
(use a diffuser or bounce off walls/ceiling)
•
Power rating indicated by Guide Number (GN)
- Calculation: GN = D x Ap
(Ex: Nikon SB800 has GN = 38 @ ISO100, 35mm
zoom)
•
Level control: Automatic or manual
- In both cases, amount of light determined by flash
duration
Flash light: Camera ‘sync speed’
•
‘Sync speed’ is the fastest shutter speed that allows
full illumination by flash
•
Try this:
1. Turn flash ‘off’
2. Set camera to ‘Manual’ mode with shutter at 1/1000sec
3. Turn flash ‘on’
4. Note change in shutter speed
The new shutter speed is the camera’s ‘sync speed’.
•
Typical sync speeds: 1/160s, 1/250s, 1/300s
(depends on camera brand)
Flash light: Control of exposure
•
Flash is typically used to illuminate a foreground
subject
•
Controlling foreground illumination with flash:
1.
Duration of the flash pulse
2.
Camera: ISO and Aperture
3.
Subject distance
Note: Shutter speed is not included
Key point:
Shutter speeds slower than the sync speed do not affect
exposure of foreground by flash
Very short
flash duration
Shutter > Sync speed
Slow
Shutter speed
Compared to flash
duration
Flash light: Dual lighting
•
A shutter speed slower than the sync speed …
- does not affect flash exposure
- allows background light to take part in the photograph
•
Dual lighting situation:
(1) Flash for foreground and (2) Ambient light for background
•
Setting the shutter speed longer than the ‘sync speed’ is called
‘dragging the shutter’
•
Method (refer to photo on next page):
1. Set camera to ‘Manual’
2. Adjust exposure for background (Aperture, Shutter speed, ISO)
(make sure shutter speed is slower than the sync speed eg 1/100s, 1/60s etc)
3. Set Flash to ‘Manual’
4. Adjust flash level for foreground exposure
(Taking these photographs in dim light conditions favours a slower shutter speed
Ex: sunrise, sunset )
Example of dual lighting:
Background (sunset) and Foreground (Flash)
More information …
http://strobist.blogspot.com
Select “Lighting 101” for 29 tutorials covering all aspects of photography
with flash
(equipment, connections, lighting techniques)
http://neilvn.com/tangents/flash-photography-techniques/
15 articles about flash photography techniques
(with lots of example photos)