managing white balance on the Olympus cameras

introduction

unlike film cameras, digital cameras can alter the colour balances to deal with different coloured light sources
this is called the “white balance” setting
light sources have a "colour temperature" which is measured in degrees Kelvin, for example:
- blue sky (ie. shade outdoors on a sunny day) = 8000K
- cloudy day = 6000K
- flash = 5500K
- midday sun = 5300K
- early morning or late afternoon sun = 4500K
- sun 1hr after dawn or 1hr before sunset = 3500K
- tungsten light = 3000-3300K
- sunrise or sunset = 2000K
whilst your WB settings do not directly affect your RAW files, they do affect the way the camera's light metering assesses the scene which could create erroneous exposures
Olympus cameras also have other settings that affect WB:
- Menu:Cogs G:All WB+/-
  - this allows you to fine tune your camera preset WB settings on the Amber and Green axes
- Menu:Cogs G:WB Auto Keep Warm Color
  - in AutoWB, it provides a warmer WB if set to ON, although it tends to be too warm in tungsten lighting
- Menu:Cogs G:flash+WB
  - allows you to tell the camera to automatically use a specific WB setting when a compliant flash is used
  - this is ignored if just using PC sync or central pin to fire a flash

when using gels on your flash and creating a custom WB, when using a compliant flash the Menu:Cogs G:flash+WB item MUST be set to OFF otherwise the custom WB will NOT be used!!!

you must be in a PASM mode or Movie mode (iAUTO, SCENE modes and some ART Filters will disable WB changes)
you must not be using Color Creator mode as this will disable WB changes
then you need to access the WB settings either via:
- open activating the Live Super Control Panel (SCP) in Olympus cameras and scroll to the WB section at top left
- press the down arrow button on rear of camera if this has been allocated to WB
- go to Menu, Cogs G, WB

in order for the camera to determine the autoWB measurement, there needs to be neutral or near-neutral tones in the scene that are within the exposure range (ie. not blown out from severe over-exposure or blocked out from underexposure).
the camera then rapidly determines the best WB setting to make these as neutral as possible

when you want consistent WB between exposures
- panoramic stitching
- HDR
- photoshoots where you want to simplify your workflow in post-processing
when there are no truly neutral tones in the scene and colour accuracy is important:
- artworks
- portraits
when you want the light source to give colour to your image
- warmth of sunsets or candle-lit subjects
- creative colour effects such as using gels on flash in daylight

you need a white piece of paper (or preferably a true neutral target) which is lit by your light source without reflective glare bouncing towards the camera
- neutral targets have LAB color space variables of a (red-green axis) and b (yellow-blue axis) equal to zero and include WhiBAL cards
- if you use normal white paper, it is actually a little blue due to optical enhancement agents which convert UV light into blue light to make it brighter, so your custom WB will render the scene a touch warm
set your exposure to ensure the paper is not blown out or severely under-exposed
perform a autofocus lock or use manual focus to avoid the next steps struggling as it can't lock AF on a plain sheet of paper
if you get error message NG Retry with the following, it means that either:
- your target was severely over-exposed, or,
- your target was severely under-exposed, or,
- your target was not suitable as a WB target (eg. no near-neutral tones)
if using a flash, ensure Menu:Cogs G:flash+WB = OFF otherwise the custom WB will not be used (unless using a non-compliant flash)

press and hold the One Touch WB button then aim camera at your target then press the shutter
you will then have the option of assigning it to custom balance 1 or 2

open the WB settings via the activating the Live Super Control Panel (SCP) in Olympus cameras or the down arrow button (is assigned)
scroll across to either custom WB 1 or 2, then press the INFO button
aim camera at your target
press the shutter button

you cannot use the Menu:Cogs:G:WB to set a custom WB although you can use this to allocate your WB to a pre-set custom WB, or you can modify a pre-set custom WB on the Amber and Green axes and preview the result using the REC button

most RAW connversion programs (eg. Adobe Lightroom) and jpeg editing software tools, allow you to change the WB setting
this can be changed to a preset value (eg. As Shot, Daylight, etc)
alternatively you can use the eye dropper to select a neutral tone in the image and the software will determine the best WB for that tone
it is handy if you have taken a shot with a neutral WB target in the scene, and then the WB setting for that image can be used on other images taken in the same lighting