James Stephens

Processing

1. Open the underexposed and overexposed images in Photoshop at the same time. The median exposure is not required.
2. Select the darker image (the one exposed for the highlights) and use CTRL+A to select the whole image. Use CTRL+C to copy the image.
3. Select the lighter image (the one exposed for the shadows) and use CTRL+V to paste the darker image (you selected in the previous step) into it. You will now see the lighter image as the Background Layer and the darker image as Layer 1:

   

4. Close the darker image as it is no longer required.
5. Add a Layer Mask to Layer 1 by first clicking on Layer 1 to select it, and then clicking on the second icon on the Layer palette as depicted in the image below.

   

   You will now see the Layer Mask as a white rectangle to the right of the image on Layer 1:

   

6. Now click on the Background Layer and use CTRL+A to select the whole image followed by CTRL+C to copy the image to the clipboard.
7. Now depress the ALT key and click on the white Layer Mask of Layer 1. The whole image will now turn white.
8. Next, use CTRL+V to paste the contents of the clipboard onto the white Layer Mask. You will now see a grayscale image of the mask contents.
9. Click to the side of the Mask on Layer 1 to reveal the blended image. It should already look quite good but there’s one more step. We need to blur the Layer Mask.
10. Navigate to Filter –> Blur –> Gaussian Blur and set the Radius to about 40 pixels. Now adjust the Radius as desired, observing the effect on the blended image.

    Here is a another example of the technique:

    
    
    Blended Multiple Exposure
    Canon EOS 300D with Tamron 17-35 f/2.8-4 Di LD lens @ ISO 100
    (click image to enlarge)

    The above image was created from these two shots:

    
    
    Exposed for the Highlights
    Canon EOS 300D with Tamron 17-35 f/2.8-4 Di LD lens @ ISO 100
    (click image to enlarge)

    
    
    Exposed for the Shadows
    Canon EOS 300D with Tamron 17-35 f/2.8-4 Di LD lens @ ISO 100
    (click image to enlarge)

    If you don’t have the time or opportunity to use a tripod and capture two images, this technique can still be used if you shoot in RAW, by processing the same RAW file with two different exposure settings. Of course then a standard exposure must be made so that shadow recovery may be conducted in one case and highlight recovery in another before the blend is done.