Advanced Tutorial 5
Exposure control is another function that is easy to leave to your camera’s automatic systems. But light metering is not infallible and a camera works differently to the human eye. This is where Exposure Bracketing comes in…
Shooting with Auto Exposure Bracketing
Getting the exposure right when you are on a shoot can sometimes prove frustrating, especially when there are bright and dark areas within the same frame. With digital photography, of course, it is easy to take a large number of shots using different exposure settings to make sure you capture the right level – provided your subject is static, not fleeting.
Most interchangeable lens system cameras offer an automatic shooting mode that specifically does this job for you. ‘Exposure Bracketing’ allows you to select a number of shots, each of which will be taken with a different exposure setting. This can either be done one shot at a time, with separate button presses, or as a burst of shots by holding down the shutter button, while the number of exposures you have specified are taken.
Three shots is commonly used to preset Exposure Bracketing, each set one f stop apart from the previous one. In these three images you can see the result, with firstly the exposure value as metered, i.e. the camera’s usual automatically selected exposure for the shot, then EV -1 f stop and finally EV +1 f stop. As you can see, it makes quite a difference and the default metered shot might not be your preferred result:
This type of shooting the same scene with different exposure values is sometimes referred to as ‘High Dynamic Range’ (HDR) bracketing and is ideal for creating a ‘hyper-real’ composition image, which is done using HDR software. We will be covering HDR shooting in more detail in a future tutorial.
Setting ‘Auto Exposure Bracketing’
Most cameras offer a number of options when it comes to choosing your bracketing method.
The screen shots here are therefore intended as a guide:
The number of shots on offer varies from camera to camera, with three shots generally regarded as the minimum requirement. More sophisticated models may offer five or even seven shots, but the best results are very dependent on the subject matter.
In most cases, three shots at one f stop spacing will provide enough scope, but for a more gradual option you may want to set 1/3rd or 2/3rd f stop spacing.
Once you have decided on the number of shots and your preferred spacing, you are ready to shoot. To start shooting in Exposure Bracket mode, go to the camera’s drive function and select the correct option.
How it looks on Panasonic’s LUMIX G models is shown here – they also offer the option to quickly change between settings via the ‘More settings’ menu:
When to use Auto Bracketing
As previously mentioned, sometimes lighting conditions make it difficult to correctly set the exposure and sometimes the camera’s automatic metering of light levels gets it wrong.
Human eyes have the amazing ability to resolve detail in brightly lit, as well as in shadowy areas. A camera, on the other hand, cannot resolve such a wide dynamic range and, therefore, a single exposure is generally weighted either to the bright part or the dark part of the image.
So, having the option to let your camera automatically select a range of different exposure values for the same scene can be very useful – and also good fun! By taking pictures with a slightly different exposure from the one that you would consider to be ‘normal’, may reveal details or emphasise colours that would otherwise have been lost.
It’s also good to experiment with different exposures for creative purposes. Deliberately under- or overexposed images can reveal an artistic look that you may find interesting.
One thing to bear in mind if you are planning to merge the images afterwards using HDR software – to create that hyper-real look favoured, for example, in some print advertising – then it is important that each image lines up exactly. Consequently it’s practically essential to shoot with your camera on a tripod.
Even if HDR composites don’t interest you, hopefully this tutorial has awakened your curiosity and inspired you to try Exposure Bracketing for yourself. So next time you get a nice sunny day, why not try it and find out what you can discover hidden in the shadows and highlights?
The LUMIX Advantage
LUMIX G cameras offer an incredible Exposure Bracketing option with a choice of three, five or seven shots. Shooting seven pictures one full f stop apart will give you an amazing six-stop dynamic range. This can enable a very impressive HDR option and with the right software is well worth trying out.
Here is what such a wide exposure range looks like:
Before you move on to the next tutorial in this module, try shooting an interesting building with a backlit bright, but cloudy sky. Have the Exposure Bracketing mode selected and compare the images afterwards for detail – in both the clouds and the facia of the building. You may be surprised by what comes, quite literally, to light!
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