Lighting / Flash

Identify - see it:

Flash Purchasing Decisions:

Guide #
____________ = fstop

Distance from subject

Flash Guide Numbers
on Flash Units

Guide numbers are a way to compare the power of flash units, but not necessarily a true indication today of all its capability. They were used historically to allow exposures to be easily calculated when flash was used, of course today we have so many other options that few now would regularly perhaps use them for this. However understanding the concepts can prove helpful especially in understanding how far your flash will reach.


Inverse Square Law :
Intensity of the illumination is inversely proportional to the square of the distance from the source. Light is dimmer in proportion to the square of the distance between the source ans subject - move flash or light twice as far away and it will be dimmer by 4x. light to subject distance.



Directional to Diffuse - Directional Diffuse

High Contrast to Low Contrast

Ambient : Exiting light source(s) natural?

Floods / Incandescent controlled



  • source (temp)
  • color
  • intensity
  • reflectance
  • intensity at the source
  • angle of view in light to subject
  • falloff

contrast | full scale, high, low key(dark tones), high key(light tones)

the smaller the harder
the larger the softer

  • fill
  • redeye
  • slow shutter
  • reduced power modes
  • forced (daylight)
  • shadow reduction
  • backlight compensation
  • bounce
  • diffuse
Shaping Light:

  • reflectors - shaped, umbrellas, flat (foam core)
  • snoot - tubes
  • tent
  • barn doors
  • diffusers , soft box
  • filtration

Misc. Terminology

front light
back light
side light

directional diffuse
Flash Util/requirements
  • varying distance
  • angle / bounce
  • diffusion screens
  • ttl/e-ttL - through the lense, electronic through the lens
  • thyristor - measure flash illumination being bounced back to sensor, shuts down with adequate exposure.

Good alternative manufacturer of speedlite flash units -

Hong Kong Yong Nuo Photographic Equipment Co. Ltd.

NEEWER® 43" (110cm) 5-in-1 Collapsible Multi-Disc Photographic Lighting Reflectors

family of angles graphic

Family of Angles from:
Light--science & magic: an introduction to photographic lighting
By Fil Hunter, Steven Biver, Paul Fuqua

misc. hardware issues:

off camera
non-relective surfaces

Calculating Guide Numbers:

the strobist


Beyond the Pop-Up Flash
By David Langs

If you haven't shot an image containing a half-moon shadow that looks somewhat like this with your digital SLR, you eventually will. That pop-up flash on your camera has a very sparse range and narrow beam, thusly it provides limited illumination for an area about 10 feet (3 meters) away. Additionally, the light source is too closely positioned to the lens, so not only do you have to deal with the arcing shadow from the lens across the bottom of an image, but occurrences of red-eye will be increased. You will, and perhaps already do, need more light to be shone on your subjects, and you may want to control not just the power but modify the direction and diffusion as well. Selecting a shoe-mount flash that is dedicated to your camera system and best fits your professional or creative needs should be an easy choice once the options and individual characteristics of each model become apparent.

Slave Units

Radio & Infrared Slaves

Optical Slaves

Pocket-Wizard Plus II Transceiver/Relay Radio Slave - Combined Transmitter and Receiver

The PocketWizard Plus II Transceiver/Relay is a triggering system that offers Auto-Sensing Transceiver Technology. This technology analyzes the status of the Plus II's miniphone jacks, camera hot shoe or the TEST button to determine which mode (Transmit or Receive) to set itself. By default, the Plus II is always in Receiver mode unless it senses a trigger pulse from a camera's hot shoe. It then quickly switches to Transmitter mode. The Auto-Sensing feature can also be disabled, if necessary.

This unit can also be used as a relay. Photographers can remotely trigger their cameras, and the camera-mounted transceiver automatically relays the triggering signal to a remote flash. With the Plus II's fast switching speed, there's no loss of camera shutter speed performance or triggering delays.

Key Features

Compatible with all PocketWizard radios past and present; also part of the PocketWizard Wireless Freedom system.

The powerful microprocessor will automatically trigger a camera and remote flash within 10 microseconds (1/100th of a millisecond) with its built-in Auto-Relay mode.

The Plus II sports the fastest triggering speed in its class, at an amazing 12 fps; it can out pace the fastest D-SLR's available.

Four selectable channels provide secure triggering. Choosing which zone to trigger (on camera flash, remote flash or both) is as easy as sliding a switch.

The Pocket Wizard II will work with sync speeds of up to 1/250 second on focal plane shutter cameras, and 1/500 second on leaf shutter cameras.

Operating Range
1600' (488 m)

4x 16-bit digitally coded channels

Maximum Flash Synchronization Speed
1/250 (focal plane)
1/500 (Leaf Shutter)

Power Source 2x AA 1.5v batteries

Pocket-Wizard MultiMax 32 Channel Transceiver Radio Slave - Combination Transmitter and Receiver

The MultiMAX features "Wireless Transceiver Technology", which eliminates the need for separate transmitter/receiver triggering configuration. Each MultiMAX provides the capability to send and receive digital signaling by a flip of a switch, similar to personal communicators.

Through its use of advanced transceiver technology, the MultiMAX offers true triggering confirmation feedback up to 1600 feet away without the need for signal repeaters or daisy-chained radios. In the "Selective Quad Triggering Mode", the MultiMAX automatically confirms (on the selected transmitter) every zone simultaneously, with immediate visual and audible feedback. Using the optional Flash Confirmation Cable, the transmitter receives a visual and audible signal, confirming that a triggered flash actually fires. Finally, there's a real confirmation system which reassures the photographer that everything is working.

The MultiMAX comes loaded with "Trigger Time Control" software. This software package offers several tools for the working professional all in one small package. With this software, it's easy and very convenient to create rear-curtain sync effects with any camera, add depth of field using multipop mode and record events as they unfold using the intervalometer mode.

Other standard features of the PocketWizard MultiMAX are up to 1600 foot triggering range, 32 digital 16/24 bit coded channels, 1/1000 flash sync speed (in fast mode), contact closure adjustment, trigger counter and much more.

Key Features

Lag Time Equalizer
Multiple Pops
Rear Curtain Sync