Advanced Tutorial 1
Experimenting with Exposure is the first step towards mastering full Manual control of your camera, rather than relying on its fully Automatic mode. Tutorial 1 looks at adjusting ISO settings, Aperture and Shutter Speed to determine Exposure for yourself, opening up a new world of creativity.
Using ‘Full Manual’ Controls, Part One – Exposure
What is Full Manual?
Modern digital cameras offer various levels of manual control that can be used in combination with automatic or semi-auto modes. We might think of some creative special effects where an entirely manual setup is required, but for the most part some aspect of ‘Auto’ control is perfectly acceptable.
Consider the elements of the shot that can be influenced by the manual controls – light, focus and exposure. As a photographer, you have a great many permutations of these options to affect your final image. Taking control over your camera and setting each of these elements manually can be a little daunting at first. Luckily, any one – or combination of – these functions can be used manually while leaving the others to auto. This means you can experiment and so gradually build your understanding of full manual control.
Over separate modules in this tutorial series we will look at these manual options in turn:
- Lighting level – Flash control
- Lighting temperature – White Balance control
- Focus control
- Exposure – Aperture, Shutter Speed and ISO control
Manual Exposure contains the widest control parameters and is, in some ways, the trickiest to master. So, we will start there.
Manual Exposure for ultimate detail & creativity
Manual Exposure mode – ‘M’ on your control dial or similar – puts you in full control of how much light is exposed to the sensor. You can set the three exposure elements: Aperture, Shutter Speed and ISO. This sets manual apart from the semi-auto exposure modes – Shutter Priority and Aperture Priority – where an element of the exposure is still controlled by the camera.
With the camera in ‘M’ mode, turning the thumb wheel allows you to alter aperture and shutter speed; pressing the wheel toggles between shutter speed and aperture control.
First, let’s fix your ISO setting
Unlike film cameras, today’s digital models can adjust their sensitivity to light electronically, which means that rather than having to load differing ‘speeds’ of film ranging in ISO from 100 to maybe 3200 – to cater for different light levels – your camera can automatically set a suitable sensitivity for the level of light available.
The choice of ISO can be dictated by a number of factors, generally it is OK to leave Auto ISO to handle the selection. However, for complete control it is preferable to select a fixed ISO, as Auto will often attempt to counteract what you’re trying to achieve with the manual aperture and shutter speed settings.
So, press the ISO control button and manually select an ISO setting, remembering that the higher the ISO, the more potential for ‘noise’ in the image.
Aperture & Shutter control
A typical tricky shot to expose correctly is the 1st example below. As a large part of the scene is brightly lit, it is difficult to expose correctly for the clouds without leaving the detail on the front of the building in the dark.
Lengthening the exposure (increasing the light to brighten the foreground details) may leave bright objects in the background (i.e. the clouds) overexposed with ‘blown’ highlights and no detail, as in the 2nd example.
By manually closing down the Aperture or increasing Shutter Speed (compared to those indicated as correct by the camera’s meter), the image will become darker and details will be increased, resulting in a good balance of brightness and detail in both areas.
Areas that are under- or overexposed lack texture and detail, so it becomes difficult to see small features or tone in these areas. The ability to correctly expose highlights and lowlights is often limited by the Dynamic Range ability of the camera. It may require multiple exposures of the same scene merged together to reach a satisfactory result – a technique called HDR – High Dynamic Range, but that’s another interesting area of photography that we will save for another day.
For ultimate creative control, setting the Aperture and Shutter Speed manually allows for some imaginative effects – It’s always fun to push the boundaries of Exposure for creative effect, as in this example where a halo has been created around the statue.
Another good use for Manual Exposure is when shooting static subjects in low light. ‘Auto ISO’ will tend to increase the ISO when light levels are low – so instead, providing you have a tripod or a solid base to rest the camera on, switch to Manual, set your preferred ISO and choose a longer Exposure.
If you want to experiment with Manual Exposure – without rendering the image unusable! – don’t worry. There are several aids on your camera that can help you work through it:
With the camera in Manual Exposure mode, the Exposure Guide-bars give an indication of how the shot would be exposed based on the settings selected.
It usually displays up to 3 stops +/- of what it calculates to be correct Exposure – as you manually adjust the Aperture or Shutter values, the indicator changes accordingly.
An excellent tool for checking Exposure, the Histogram reads off the sensor and displays how many pixels are detecting low, mid and high tones across the brightness range.
The aim is to set the Exposure so the peaks of the Histogram are not weighted too much in the low-light areas (underexposure – lack of detail in shadow), or in the high (overexposure – lack of detail in bright areas).
How to fully interpret the histogram is not something to be covered here, but we have a later tutorial that provides a more detailed explanation.
Another useful aid is the Highlight Warning, which is used in Review or Playback mode to highlight areas of the scene that are too bright (blown highlights).
With the function switched on, any parts of the shot that are overexposed will flash black-and-white to alert you. This type of warning is similar to the ‘zebra pattern’ warning.
So by using the available camera tools, practice with fine Exposure control and soon you will be comfortable with the intricacies of the Aperture and Shutter settings.
The LUMIX Advantage
LUMIX G cameras include an Exposure Meter Guide that displays on-screen whenever you are making changes to the Aperture or Shutter Speed. In ‘M’ mode, it can be used in conjunction with the Exposure Guide-bars and shows you the range of Exposure settings that are available in order to keep the image correctly exposed.
With the ‘Highlight’ warning switched on in the ‘Custom Set-up’ menu, try taking some shots indoors and outside of some bright white or brightly lit objects. Check the playback to see what parts of the image are overexposed. Then, shoot again using the Manual Exposure controls to expose the bright parts correctly. Choose a subject with fine details, like a white flower or, as in our examples, a detailed building against a bright sky.
So that completes Part One of our guide to Using Manual Controls and hopefully gives you the confidence to try Manual Exposure for yourself. Part Two follows in the next module where we will be covering Lighting and White Balance.
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