How in-camera pre-sets can assist with low-light shooting.
Dedicated low-light shooting modes enable photographers to use very slow shutter speeds to minimise the chances of introducing blurring due to camera shake.
Almost since the first point-and-shoot digicams were invented, camera manufacturers have come to the aid of novice photographers by providing pre-set exposure modes to help them select appropriate aperture, shutter speed and ISO settings for popular photographic genres. The first of the ‘Scene’ pre-sets were for portrait, landscape and sports photography. But it wasn’t long before night portrait and night landscape pre-sets were added and it’s not uncommon for modern cameras to provide separate pre-sets covering fireworks, candlelight, sunset and dusk and/or dawn.
But it hasn’t stopped there. Since camera manufacturers figured out they could ‘stack’ multiple exposures with in-camera processing we’ve seen Handheld Twilight, HDR (high dynamic range) and Anti Motion Blur modes, each of which uses multi-frame recording to create a single image with less noise, an expanded dynamic range or reduced motion blurring.
Scene pre-sets come in handy when you have a momentary ‘can’t cope’ situation where you’re not sure what aperture, shutter speed and/or ISO settings to use and you need to work quickly. Selecting the right one takes a second, while it may take a minute or more for you to determine the best exposure settings and configure the camera accordingly.
Like all camera controls, pre-sets involve different combinations of the three key exposure controls: aperture, shutter speed and ISO sensitivity. The secret behind their success is being able to balance all three to achieve the optimal brightness and contrast levels, adequate depth of field and minimal image noise.
The main pre-sets used for low light photography are the night portrait, night landscape, fireworks, museum, candlelight, indoor/party, sunset and dusk/dawn modes. The following summaries provide details on the situations they are designed to address and how they configure the camera.
1. Night Portrait
This mode is for taking portrait shots after sundown, where a natural-looking balance between subject and background detail is required. In most cameras it will pop up and switch on the flash and activate face detection. A slow shutter speed will be selected so use of a tripod (or other form of stabilisation) is recommended for this mode. Sensitivity is adjusted to optimise noise levels. Red-eye reduction processing is engaged if the camera supports it.
The Night Portrait mode combines balanced flash with ambient lighting and usually includes face detection.
2. Night Landscape
This mode is for taking photographs at night where both close and distant detail must be captured and natural colours are required. It can be used for subjects other than landscapes, including cityscapes and interiors of buildings. The camera’s flash is switched off and low ISO settings are prioritised. A slow shutter speed is selected and the daylight white balance setting is selected. Use of a tripod is highly recommended as exposures may run to several seconds.
The night landscape mode uses a slow shutter speed and sets the focus to record a wide depth of sharpness. It can be used for cityscapes but moving subjects will appear blurred. Ideally, the camera should be tripod mounted.
The purpose of this mode is self-explanatory and, like the Night Landscape mode, it relies on having the flash switched off. The lens focus is set to infinity and a slow shutter speed is selected. ISO settings depend on ambient light levels. Mounting the camera on a tripod (or some other form of stabilisation) is essential as exposures may be several seconds long.
The fireworks mode suppresses the flash and combines a slow shutter speed with focusing the lens on infinity.
Although not strictly a low light mode, the Museum pre-set is designed for indoor photography where use of flash is prohibited. In some cameras it also disables camera beeps, enabling shots to be taken silently and unobtrusively. To cope with hand-held shooting, a high ISO setting is usually selected, along with a relatively fast shutter speed. The continuous shooting mode may be engaged to minimise the risk of camera shake.
The museum mode is designed for indoor photography where you can’t use flash.
This mode is designed for indoor portraits in dim artificial lighting where warm colours are desirable. As well as switching the flash off and activating face detection, it will select a high ISO value and daylight white balance. Some cameras add slight overall softening to create a more aesthetic effect.
A typical application for the candlelight mode, which set the camera’s ISO to 400 and selected a shutter speed of /130 second at f/4 for the 40mm lens used for the shot.
The Indoor or Party mode is designed for taking photographs (mainly of people) with a hand-held camera in a dimly-lit room, usually under artificial lighting. The shutter speed is usually set to the slowest speed at which the average photographer can keep the camera steady for the selected focal length. The ISO and aperture are adjusted for the room brightness. If the flash is used, its output will be balanced to match the ambient lighting, ensuring a natural-looking result is obtained.
The indoor/party mode is designed for taking photographs with a hand-held camera in a dimly-lit room.
This mode is all about preserving and enhancing the warm tone in sunset shots. It will The camera will switch off the flash, set the focus to infinity and set a daylight colour balance, which will probably be biased towards red to achieve the main objective. ISO settings will generally be selected from the lower end of the available range.
The sunset mode may boost reds and yellows to emphasise the warm tones in sunset shots.
These settings have been designed to preserve a natural colour balance in pre-dawn and twilight shots. The ISO will be set as low as possible for a shutter speed at which the average used can hand-hold the camera. The focus may be set to infinity. Color saturation may be increased and a magenta filter may be added.
The dusk/dawn pre-set aims to preserve natural-looking colours in pre-dawn and twilight shots and may add a weak magenta filter to correct a greenish bias in the light.
9. Handheld Twilight
This mode was introduced by Sony in about 2010, initially in Cyber-shot digicams, although it later became more widespread. The camera captures six frames in rapid succession in less than a second, using very short exposures to minimise blurring. These exposures are combined in the camera to produce an image using noise-reduction processing to minimise noise in low-light shots.
The flash is disabled and you can’t adjust most camera settings. You can hear the shutter firing multiple times. For night and low-light shooting, this mode can deliver images with less noise and a better exposure balance than similar shots taken with a single exposure.
The Handheld Twilight mode records a series of frames with short exposures to minimise blurring and combines them to produce a single image. For night and low-light shooting, this mode can deliver images with less noise and a better exposure balance than similar shots taken with a single exposure.
10. Anti Motion Blur
This mode appeared at the same time as the Hand-held Twilight mode and uses a similar exposure method: six frames are captured in less than a second and combined to make a single image. In this case, priority is given to image sharpness by overcoming blur due to movement in low light.
Image stacking involves two processes: capturing a number of photographs of a subject without altering the camera’s position or the lens adjustment and combining them into a single image. Astronomers often use it for recording images of the night sky when the camera is attached to a tracking tripod. Photographers use it for capturing star trails.
The process is relatively simple. Set up the camera on a sturdy tripod, pointing at the sky (or the subject you want to record). Then use the time-lapse function to record a sequence of, say, one-second exposures at intervals of between 10 seconds and a minute. Longer intervals will produce gaps in the trails, resulting in a ‘dotted’ effect.
Keep on recording for a long time; ideally at least 30 minutes. In general, the more photos you take, the more detail you can pick out and the more uniform the background noise becomes after averaging.
An example of the use of image stacking in Photoshop CC. Seventy-eight frames recorded with the time-lapse mode on a Panasonic GH4 camera over a 35 minute period have been combined to produce this image.
Users of Photoshop CC can combine their images via the Statistics function (File > Scripts > Statistics), which provides an interface for selecting and loading up the images to be combined. Select the Maximum setting from the Choose Stack Mode drop-down list to choose the brightest pixel at every point of the blend.
The stacked files appear as a Smart Object in the Layers panel in Photoshop CC. To combine them into an editable file, click on the Layer tab in the top menu and select Flatten Image.
The latest Olympus OM-D cameras include a Live Composite shooting mode, which is designed for capturing shots of star trails and uses image stacking to combine multiple relatively short exposures into a single image that extends over a long period of time. Total recording time can be up to three hours.
The camera captures a single initial exposure to record the brightness levels in the scene, and these are used to determine the subsequent exposures. Photographers can select the ISO sensitivity, lens aperture and shutter speed settings before pressing the shutter button again to initiate the exposure.
Each frame is exposed for the pre-set duration and the camera will continue to record frames, displaying the results on the monitor screen. When the end result is as you want it, pressing the shutter button stops the recording process and the camera will combine all the frames to create a composite image.
This mode can be used for JPEGs or ORF.RAW files or a combination of both. As well as shooting star trails, it can also be handy for capturing shots of fireworks and light trails, attractively blurred shots of flowing water and blurring moving subjects against a static cityscape.
Article by Margaret Brown
Excerpt from Photo Review Issue 68