For years photographers have used the technique of bracketing images to achieve the best exposure. Instead of taking just one image, you take a series of images at a range of exposures, giving a selection to choose from ranging from darker to lighter. These can now be combined digitally to make a perfect photograph.
Words and Pictures Aidan O'Rourke
1. Here we see two image captures of the same subject displayed side by side, one exposed for the exterior and one exposed for the interior.
Looking at the lighter image on the right, we see that the brightness levels for the interior are about right, but the exterior, and part of the reflection from the floor, are too bright. In fact, they are overexposed, i.e. too much light has fallen on the light receiving surface of the digital camera, and this area has 'burned out' to white.
2. In this image, we have combined the lighter and the darker images. We did this using 'Layers' in Photoshop. We placed the darker image on the background, and the lighter image on a layer above it. Then using the delete tool, set to airbrush 150 pixels diameter, we delete part of the lighter picture, revealing the darker one underneath. The effect is shown below:
3. We can see how the lighter picture looks by switching off the darker picture underneath. The checkerboard pattern of Photoshop's background can be seen underneath.
4. The darker area underneath looks a little too dark. Using Levels we can lighten it a little. The updated image is shown below:
5. The image is cropped slightly to make the composition more balanced. The end window is now in the centre of the frame.
6. Let's view the finished image at large size. We can see how the range of tones is even, and details of both the interior and the exterior are clearly visible. It would not have been possible to achieve this degree of clarity with just one image capture.
Camera: Nikon Coolpix 990
Date: April 2001
About this picture
The Blue Souqs are one of the main tourist attractions in the emirate of Sharjah, United Arab Emirates. In the souqs, Arabic for markets, you can buy gold, watches, electronic goods and souvenirs. The Blue Souqs are built in a style which recalls the golden age of Islamic architecture.
Aidan ORourke has been a practitioner of digital photography since 1994 and produces the photography-information website Eyewitness in Manchester
(part of Manchester Online). He writes the Question and Answer pages in Digital Camera Magazine. See Aidan ORourkes portfolio site.