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Taking Pictures under Available Light

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Summary

Most modern digital stills cameras have built in flashes, however these do not always produce a pleasing light, have a limited range and the flash can be distracting in some situations. Professional photographers normally like to have complete control over lighting in order to produce the highest quality images. It is however possible to produce high quality images without the cameras built in flash or in situations where you do not have total control over the lighting. Available or ambient light is the light in the scene before the photographer starts work and this FAQ document looks at common problems associated with available light and how to overcome them. You may also be interested in our Light Sources for Still and Moving Images advice document.

What is available light?

This is the light present in a scene before the photographer or filmmaker starts work. It could be bright sunshine, moonlight, torchlight, classroom lighting or normal office or domestic lighting.

My camera’s built in flash produces very harsh lighting, can I switch it off and use a desk light?

You should be able to switch of the camera’s flash and use the available light, however if the light intensity is low, shutter speeds tend to be longer which increases the risk of camera shake. To reduce camera shake place the camera on a stable surface or better still a dedicated camera support. There is more information on reducing camera shake in the JISC Digital Media document on Stands and Supports for Still and Moving Images.

A desk light should be quite capable of lighting small objects. With a little care you should be able to adjust the ‘hardness’ softness’ of the light and use reflectors to shape the lighting on the subject. Low energy fluorescent lights are rapidly replacing tungsten bulbs and so it is important that you identify the type of bulb in the fitting. Digital cameras can identify and correct (white balance) for most types of lighting however some fluorescent bulbs do not emit a full colour spectrum and the subject colour may not be accurately rendered. In Figure 1, below the group of objects were illuminated with the camera’s built in flash. Figure 2 shows how a subject can be illuminated using a desk light with a white card reflector to reduce the shadows on the left side. The bottom image, figure 3 shows the results of using a desk light.

object photographed using built in flash
Figure 1. Photograph taken using built in flash. Note the hard shadows behind objects

Using desklight to light object
Figure 2. Taking a picture using a desk lamp and reflector

Photograph taken using desklamp
Figure 3. Image taken using desk lamp. Note the softer shadows around objects

I am trying to taking a picture under very bright light, why is my camera overexposing?

Under dark conditions the shutter can be kept open for as long as required providing the camera can reduce the image noise however for extremely bright conditions the camera is limited to the fastest available shutter, the smallest aperture and lowest ISO ( sensor’s sensitivity to light). If the intensity of the light itself cannot be reduced the only way to capture a correctly exposed image is by absorbing some of the light in a filter.

Neutral Density (ND) filters are placed in front of the lens and absorb some of the light before it reaches the sensor or film.

I want to photograph classroom activities without disturbing those present with a flash, is that possible?

You should be able to take pictures in a classroom without flash if there is enough available light. If moving subjects are appearing blurred then you may need to open the aperture to increase the shutter speed or raise the ISO. The camera should also be on a firm support. It is important that you have informed those present that you wish to take images and have consent to include them in your photographs.

I am using a couple of 100 watt tungsten filament bulbs to illuminate an object, I am using the Auto White Balance (AWB) setting and the images are a bit orange, am I doing something wrong?

The Auto White Balance setting is effective at identifying and correcting the colour under most types of lighting but it can on occasion be confused. Most cameras offer a choice of different white balance settings including the AWB, preset settings for specific light types and a measure feature, which allows you to photograph a white card to identify the colour temperature of the lights. It may be worth shooting three test shots, one using the AWB, one with the tungsten/incandescent setting the last with the measure setting. You can then compare the results on a high quality calibrated monitor and use the setting which produces the most accurate results. If you change your camera’s white balance settings remember to check or reset them before you next use the camera.

How can I capture the surface texture of an object?

Directional lighting is normally the best way to capture the texture of a subject, if a light can be positioned close to 90 degrees to the angle of the lens. The light should then skim across the surface of the subject and emphasise the texture. If the texture is too strong and detail is lost in the shadows then a reflector can be used to ‘bounce’ light from the opposite side to the direction of the light or a diffusing material can be placed in front of the light.

I am photographing a number of similar documents and lighting them with a fluorescent light. Why are some images darker and with a different colour to the others?

There are many different types of fluorescent lighting, some offer photographic quality while other have a limited spectrum and may not produce images with an even colour lighting. Normal mains AC electricity alternates at 50 cycles per second (50 Hz). This rapid fluctuation in the current produces a flicker in most types of domestic and office lighting however it is more pronounced with fluorescents. Through a single cycle the colour and tone can shift dramatically, a brief exposure could capture a light or dark point in the cycle. To avoid taking an image at a very dark or light point in the cycle use a shutter speed equal or slower than the AC frequency of 50 Hz. You could switch your camera’s exposure mode to shutter priority and set a shutter speed of 1/50th or slower to capture a whole cycle within the exposure.

Image showing variation between images taken under fluorescent light

Image showing variation between images taken under fluorescent light
Four images taken under fluorescent lighting using the same exposure settings. Note shift in tone and colour between images

Can I take pictures in a dark lecture theatre?

If you can see the subject even in the dark then you may be able to photograph or film it. For stills photography you will probably have to use a long exposure so the camera should be mounted on a stable support to avoid camera shake. Filmmakers may be able to increase the camera’s gain to pull more information from the shadows. Digital stills and video cameras often produce visible interference or ‘noise’ to long exposure images. While the lecture theatre is mostly dark there may be pools of bright light such as projector screens or monitors which can confuse the camera’s light meter. Most cameras offer exposure compensation so that the exposure can be increased or decreased to correct for exposure problems.