Advanced Tutorial 2
Returning to your camera’s manual controls, this tutorial looks at ‘colour temperature’ and White Balance settings. By choosing the correct preset or going for full manual, learn how to ensure your images capture true-to-life colours, whatever the ambient lighting conditions.
‘Full Manual’ Part Two – Lighting & White Balance
The first tutorial on manual controls looked at exposure; here, we are considering adding more light with a flash and making sure colour is captured correctly via the White Balance settings.
As we know, photography is all about capturing light – how much falls on a subject dramatically affects the way a picture will look.
When to fire the flash?
If ambient levels are low, using a camera’s built-in flash provides additional light at the moment of exposure. If that’s insufficient, a more powerful flashgun can be connected.
One of the notable things when stepping up from a compact to a DSLR or DSLM is that the flash works in a completely different way – because interchangeable lens cameras usually incorporate a ‘pop-up’ flash unit. Some cameras can be set to release the flash and fire automatically as needed. Others rely on the user releasing the flash manually before it is able to fire.
Use the manual option to fire the flash where your subject is in need of extra light to improve exposure, or to eliminate shadows, such as when the subject is strongly lit from one side or behind. Of course, there is always the option to use no flash at all, or to force the flash off, making full creative use of the available ambient light.
Manual flash control
Adding a bright flash at the point of shutter release may seem like the simple option. Actually, there are several factors and camera controls to consider – shown here are the first level basic options.
Select the right type of flash
There are five main modes for controlling the firing of a built-in flash (or external flashgun):
Flash Forced On: whenever the flash is ‘popped-up’ it will fire, irrespective of ambient light.
Flash with Red-eye Reduction or Anti Red-eye: a smaller pre-flash fires prior to the shutter opening. This affects subjects’ eyes, reducing the chance of retinal reflection – the red-eye effect – at the main flash.
Slow Syncro: enables a longer exposure to capture light from the flash that has traveled further away. This brightens the background, bringing in more detail when shooting in darkness.
Slow Syncro with Anti Red-eye: combining the two – used when shooting people at night in front of featured backgrounds.
Flash Forced Off: when you don’t want the flash. This option only appears when using external flashguns. For pop-up flashes, simply leave it down.
A flash is not only for night shoots – during the day, a strong light source may leave your subject in shadow. The built-in flash can light your subject from the front and compensate for shadows. Beware when the lens hood is fitted though, as it will cast a shadow itself! Remember to remove it first.
Slow sync & 2nd curtain syncro
Slow Syncro is an excellent option for introducing more features into a shot when shooting at night. In Program AE mode, using the flash normally sets the exposure to 1/60th sec, which does a good job of isolating a subject from a dark background. But, to include background details, switching to Slow Syncro allows exposures up to 1 sec.
Below, you can see the difference between shooting regular flash and with Slow Sync.
Note: the longer exposure times associated with Slow Sync can easily result in a secondary blurred exposure due to camera shake – keep the camera still for the duration of the exposure, ideally on a tripod. On most System Cameras, it is also usually possible to control the timing of the flash in order to capture special light effects. This is the ‘Shutter Sync’ or ‘Curtain Sync’ option.
2nd Curtain Syncro – In normal circumstances, the flash is synchronised with the first shutter curtain being fully open – synchronising it with the second instead, means the flash fires towards the end of the exposure.
This gives an interesting light-trailing effect when photographing moving subjects in very low light, especially with slow shutter speeds.
The image (left) is an example of a 2nd curtain sync shot. Due to the flash firing near the end of the exposure, the subject is illuminated and frozen with a light trail following the motion.
How much light is added?
Every electronic flash device has a ‘guide number’ (GN) in its spec giving its approximate light level and range. It is quoted in feet or metres and is usually measured at ISO 100. The built-in flash on the LUMIX G6, for example, is rated GN 8.3 at ISO 100 or GN 10.5 at its minimum ISO 160. This means the flash will give the correct exposure of a subject 10.5m from the camera at the widest aperture of the kit lens; this is only a guide of course, as different lenses will affect the results.
The distance from the camera to the subject is very important for obtaining good results with a flash. Light output diminishes as it travels out, so subjects too far away will be underexposed. Conversely, subjects too close will be overexposed, ‘washed out’. So, it is usually possible to manually adjust flash intensity by +/- three stops in the setup menu.
Information on advanced use of flash and using external flash guns is covered in later tutorials of this advanced module.
Lighting temperature / White Balance
The type of light source illuminating a scene can affect the subject’s colour when captured on camera. For accurate colour reproduction, the image sensor must be set at a reference colour temperature, known as the White Balance (WB). All light source output is measured on a Kelvin colour temperature scale, from the hottest (9,000-10,000 K) bluish/white light of a clear sky to the coolest (1,000-2,000 K) reddish/yellow of a candle flame. The camera therefore needs to estimate the temperature of the light source.
Within a common range of light settings, the camera does a pretty good job of working out temperature. Sometimes, however, you may notice a bluish – as in the first example – or yellowish tinge in photos, indicating the camera has not adjusted from a previous shot or was left with the wrong setting.
Preset and manual WB control
The first thing to do to help your camera select correctly is pick a colour temperature preset – via a WB mode button or the menu. Apart from the AWB (Auto) mode, you will see some icons: Bright Sun, Cloud, Shade, Indoor Light. Simply select the correct preset for your shooting conditions.
Take a look at the next two shots, where due to the colour of the wall the camera had difficulty selecting the correct colour temperature.
If the best preset option isn’t achieving accurate colour, manual setting for the location will be necessary – by pointing the camera at a flat white object in situ. In ‘WB Set’ mode, fill the frame with the white surface and press ‘set’. The camera will recalibrate colour temperature to show the correct white on-screen. As long as the ambient light doesn’t change, you can now shoot in this location with accurate colours – see left – without resetting again.
Never underestimate the importance of getting the White Balance correct. It can make a big difference to the colour accuracy of your photos. Don’t always rely on the camera’s AWB to get it right every time.
When moving from shooting outdoors to indoors (or vice versa), either allow time for the AWB to adjust, or select the correct preset. But, for total accuracy, whip out that handy white card!
The LUMIX Advantage
LUMIX G cameras always display ‘Live View’ through the electronic viewfinder or LCD screen. This has the advantage of showing you the WB colour temperature before you take a shot. Even with manual colour control or adding artificial colour hue, the effect can be easily seen, in real-time, as you make adjustments.
Have you tried the various WB presets? Check out the effects of colour temperature in different shooting environments and practice setting WB manually with a piece of white card. Tip – a single sheet of 15 x 10cm photo paper is ideal, keep it in your camera kit bag.
So that completes the 2nd part of our guide to Manual Controls and hopefully will inspire you the next time you think ‘the lighting in this shot is not quite right’. Part Three follows in the next tutorial where we will be covering – Manual Focus.
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