Faking it

Of course not everyone is lucky enough to have access to Adobe Photoshop CS2 or CS3, so for users of other image editing programs there is another alternative. It’s not really HDRI, but it is possible to combine several different exposures of the same image into one, achieving a similar effect. As usual, for this section of the tutorial I’m using Adobe Photoshop Elements 5, but the same technique can be used in any image editing program that supports layers, including Paint Shop Pro, PhotoImpact and GIMP. For this, we’ll use some of the same shots I used for the previous section.

In your image editor, open one image that has the interior correctly exposed, and another that has the highlight detail correctly exposed. Select the lighter of the two images, and use the keyboard shortcut CTRL + A to select the whole frame, and then CTRL + C to copy it to the clipboard. If you don’t like shortcuts, use the Select All and Copy from the Edit menu.

Click on the darker image to make it the active image, and use CTRL + V to paste the copied selection as a new layer (Paint Shop Pro users should use CTRL + L). You should now have two versions of the same frame as separate layers in the same image.

Select the Eraser tool from the tool palette, and choose a soft-edged brush of a suitable size. For this large image I’m using a 100-pixel diameter brush, but the appropriate size will depend on the size of your image.

Using the eraser tool, carefully paint over the burned-out highlights, so that the correctly exposed layer below becomes visible. You will find it easier to do this accurately if you zoom in a bit, and you may also need to vary the size of your brush to work around fine details.

Once you’ve gone over all the highlights, flatten the image and save, and then open a third frame which has good shadow detail. Copy and past your combined image onto this one as a new layer, and then go over the under-exposed shadow areas with the eraser, to reveal the correctly exposed shadows from the layer below.

With care and patience, you should be able to achieve an effect that is very close to the genuine HDMI image produced by Photoshop.

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