Pick n’ Mix for lovers of dynamic detail For those who like to have their cake and eat it, Mark Galer introduces a two into one post-

production editing technique to extract all of the detail from your information rich RAW images.

Fig 00a. Unleash the detail from your camera RAW files and enjoy extended dynamic range

Are your images suffering from the black hole syndrome? You take a picture of a sunrise or sunset

and the immediate foreground is a silhouette with little if any detail. If you increase the exposure to

rescue detail in the foreground you then loose the sky to overexposure. Although your eye can

register detail in both the highlights and the shadows the image sensor of the camera is seriously

challenged in these situations. The contrast of the scene is said to exceed the dynamic range of the

image sensor. There is however hope – and it lies in the ability of the camera’s sensor to record a

broader range of tones than are usually rendered or processed to the JPEG file format in the camera.

Dynamic Range is the ability of the camera’s image sensor to record the subject’s brightness range

from the deepest shadows to the brightest highlights. The greater the dynamic range of the sensor,

the broader the range of tones that can be recorded. The large image sensor’s found in typical

digital SLRs can capture a broader range of information than the digicams using smaller sensors.

This broad dynamic range however, can usually only be accessed if the DSLR owner switches from

the JPEG file format to the camera RAW format in the camera’s quality menu so that the

information is processed by Photoshop rather than by the camera.

Note > If you have a new Digital SLR you may need to download a camera RAW update for either

CS2 or Elements 4.0. If the software’s RAW plug-in is older than your camera then Photoshop will

not be able to recognize the RAW files from this new camera. The most recent camera RAW plug-

in is 3.3 and supports recent models such as Canon’s 5D, Nikon’s D200 and the Olympus E-500.

To access the latest plug-in go to http://www.adobe.com/products/photoshop/cameraraw.html

Fig 00b Use the exposure slider in the camera RAW dialog box to increase either the highlight detail or the

shadow detail

When the RAW file is opened in Photoshop Elements or Photoshop CS2 the exposure slider in the

camera RAW dialog box allows the user to choose an increased or decreased exposure setting from

the one that was selected in-camera and used to capture the image. This allows the photographer to

access either increased highlight information or increased shadow information after the image has

been captured. When the image is opened in Photoshop’s editing space the RAW file closes and a

copy of the file with your preferred exposure setting is opened into the main editing space of your

Photoshop software.

Note > When the RAW information is processed the preview and thumbnail of the RAW file

reflects these preferences but the RAW data cannot itself be modified. This RAW file can be

processed a second time with a different set of preferences for exposure, color and tone.

Fig 00c. The same RAW file can be processed twice to achieve optimum highlights and optimum shadows

To achieve the optimum dynamic range that is possible from the information recorded by the image

sensor (increased shadow detail AND increased highlight detail) we can open two images from the

same RAW file, each file being optimised for a different end of the exposure range. In Photoshop

we can then simply merge the two exposures together. Some would call this manipulation when in

reality all we are doing is restoring the tonality back to how our human vision first saw the scene

rather than how the camera interpreted it.

Fig 01. Open your camera RAW file in the Adobe Camera RAW dialog box

1. Open your camera RAW file in the Adobe Camera RAW dialog box. Move the Exposure slider

to the right until the shadow detail has opened up and the detail is clearly visible. Pay no attention

to the highlights that will now be overexposed. If you have the Shadows and Highlights boxes

checked the color red indicates that massive amounts of highlight detail is being lost or ‘clipped’.

Notice however how the tall peaks on the left hand side of the histogram move away from the left

side as you move the exposure slider to the right. If the shadows are rich in detail but appear flat

and grey you can compensate for these by raising both the Contrast and Saturation sliders. Zoom in

to 100% and check the shadows for excessive noise. If noise is a problem proceed to the Detail tab

and raise the Luminance Smoothing and Color Noise Reduction sliders to the right until the noise is

sufficiently suppressed. Set the Depth in the lower left hand corner of the dialog box to 8

Bits/Channel and select Open.

Fig 02. Save and name the file

2. The first file will now open in the main editing space and the RAW file will close with your

settings saved. Before opening the master RAW file into RAW dialog box a second time it is

important to save and rename the first file otherwise Photoshop Elements will be confused as to

why you want to open the RAW dialog box a second time when you have already processed an

image that is still open in your editing space.

Fig 03. Optimize the settings for the highlights

3. When the RAW file opens in the RAW dialog box for the second time you can now move the

exposure slider to the left to optimize the image for the highlight detail. Choose an appropriate

setting for the Contrast and Saturation sliders and again select the ‘Open’ button.

Note > In the example some highlight clipping remains even with an exposure setting of -1.75.

If you are presented with this scenario the only way of achieving additional information is to

bracket the exposures whilst the camera is mounted securely on a tripod during the initial capture.

Fig 04. Combine the two exposures in Photoshop’s main editing space

4. Now that you have two files opened from the same camera RAW file you can start to combine

the best aspects of each exposure. Start the process by selecting the darker image and then dragging

its thumbnail from the layers palette into the image window of the lighter first image. Hold down

the Shift key as you let go of the thumbnail to ensure that both exposures are perfectly aligned.

Fig 05. Create a layer mask for the purpose of merging the two layers

5. The next step involves adding a layer mask. Users of the full version of Photoshop can simply

select the top layer and then click on the Add layer mask icon in the Layers palette. This procedure

is off-limits to users of Elements so they must instead add an Adjustment Layer and use its

accompanying layer mask instead. To create an adjustment layer for this purpose first select the

‘Background’ layer in the Layers palette and then click on the Create adjustment layer icon and

choose Levels. Do not make any adjustment in this dialog box but simply select OK.

Fig 06. Elements users must group the top image layer with the adjustment layer to use its layer mask

6. Photoshop Elements users must now Group the top layer with this adjustment layer to link the

layer mask to this image layer. Click on the top layer to make this the active layer and then from the

Layers menu choose Group with Previous.

Fig 07. Select the gradient tool and options

7. In the Tools palette choose The Gradient Tool and from the Options bar choose the Black, White

gradient, Linear option with an Opacity of 100%. Click on the layer mask to make this the active

component of the layer.

Fig 08. Add a linear Black, White gradient to the layer mask to merge the two exposures

8. Move the cursor into the image window and click just below the horizon line. Hold down the

Shift key and drag the gradient to a position just above the sun and then let go of the mouse clicker.

This action will add a gradient to the layer mask and will act to hide the darker foreground pixels in

the top layer. We will now be able to view the sky from the image with the decreased exposure and

the foreground from the image with the increased exposure.

Note > A more complex mask is often called for when the subject is not so clearly defined as a

bright sky and a dark foreground. If this is the case you can paint directly into the mask using a soft-

edged paintbrush with the foreground color set to black and the opacity dropped to 50%.

Fig 09. A duplicate layer in overlay mode is used to increase the contrast and saturation of the sky

9. To create the right balance between the foreground and background it may be necessary to fine-

tune the image. We could have increased the contrast and saturation of the decreased exposure in

the RAW dialog box but it was difficult to gain an idea of what the two images would look like

when combined at this stage of the process. In this project it was decided to duplicate the top layer

and switch the mode to Overlay (drag the layer to the new Layer icon in the Layers palette). You

will notice that the duplicated layer is still part of the group and so the mask shields this layer as

well as the layer beneath. The Overlay blend mode has the effect of increasing both the contrast and

the saturation of the sky. The effect is that the image now looks like how I remembered the scene

when I first raised the camera to my eye.

Fig 10. The layers are merged and the resulting layer sharpened for printing

10. To complete the project the image can be sharpened. As the image is now the result of pixels on

three different layers the image must either be flattened or alternatively, the information from the

three layers can be merged and pasted into its own layer. The keyboard shortcut that makes this an

easy affair is to hold down the Ctrl+Alt+Shift modifier keys and then type the letter E (CS and

Elements 3 users must type the letter N followed by the letter E). The project image was sharpened

using the settings Amount:180, Radius 1.5 and Threshold 5.

Note > Mac users need to hold down the Command key instead of the Ctrl key.