Combine multiple raw exposu res

shadow detail

George Cairns shows you how to combine bracketed raw exposures to reveal important detail throughout a shotentire tonal range

At the height of summer it can be a challenge to meter a sunny scene to get a perfect exposure. If you set the aperture and shutter speed to reveal detail in a landscapeshadows, for example, you run the risk of blowing out the sky s highlights. By closing down the aperture to capture highlight detail youlose shadow detail.

By shooting in raw quality format you can capture much more information about a scenetones. Although a raw shotsky may appear overexposed you can use the Adobe Camera Raw (ACR) editorRecovery slider to claw back missing detail

without darkening the shotshadows. Weshow you how to use the ACR editor to target and tweak specific tones to get a more balanced exposure.

If you set your camera to its bracketing mode (see box, right) you can capture three different exposures of the same scene. One will have shadow detail, the other wall include lots of midtones and the last will contain valuable highlight information.

Here, weshow you how  to process three bracketed shots in the ACR editor to reveal detail in particular tones, and then use Layer Masks to blend the best bits together to create a single composite image with a balanced exposure.

Prepare the start files

1 Click on the link (below left) to download the Basic folder. Drag highlight_.before.dng, midtone_before. dng and shadow_before.dng into a folder on your hard drive. Launch Elements and go to File Open. Browse to the folder containing the bracketed start images. Hold Shift and click to select them all. Click Open.

Open the images

2 Because the bracketed images are digital negatives, they will automatically open in the Adobe Camera Raw editor. You can tweak them to maximise detail in the shot s shadows, midtones and highlights. You can then combine the separate shots into a well-exposed composite image.

Reveal highlight detail

3 Click on highlight_before s thumbnail. This shot was exposed to reveal detail in the bright sky. To ensure you have all the highlight information, reduce Exposure to-0.55. Boost Vibrance to +32 for a bluer sky. Don t worry about under-exposing the shadows.

Adjust the midtones

Click on midtone.before.dng. Here, we re only interested in revealing the building s detail. Slide Fill Light to 33 to brighten the midtones. Boost Blacks to 18 to darken shadows. Push Contrast up to +74. Increase Clarity to +24 to reveal the brickwork s midtone detail.

Tweak the shadows

5 Click on shadow_before s thumbnail. This shot is exposed to reveal shadow detail, so the highlights are really over-exposed. Drag Blacks to 16. This darkens the trees  shadows without under-exposing them and losing any of the detail. Increase Vibrance to +32 to enhance the foliage.

Clipping warnings

6 Press U to see under-exposed shadows as blue patches and O to view over-exposed highlights as red patches. Shadow_before has plenty of shadow detail, but totally blown-out highlights. Fortunately, no sky pixels are clipped in highlight_before, so you know you have detail throughout the entire tonal range.

Select and open

Click Select All in the ACR editor, then click Open Images to take shots into the Photoshop Elements editor. Here you can combine the correctly exposed bits from each processed shot to create a composite with detail in the shadows, midtones and highlights.

Cycle through

8 Press Ctrl+Tab to cycle through the three images. Because the camera was handheld, the building jumps around in each shot. This can cause blurring when you mix correctly exposed parts of the images. You can align them manually, but there s a quicker way.

 midtone before

Automatic alignment

9 Go to New>Photomerge Panorama. Click Add Open Files to include your three exposures.

Leave Layout set to Auto. Untick Blend Images. Tick Geometric Distortion and click OK. Photomerge will place the shots onto separate layers in a new document.

Compare the layers

10 No Wen asked if you want to automatically

I KJ fill in the edges of the combined shot. Tick the eye icon to toggle the three layers on and off.

The building will now remain rock steady on each layer. Only leaves and strolling people will change position.

Crop the shot

To remove the transparent edges around the layers, grab the Crop tool from the Tools palette. Set the drop-down option to Use Photo Ratio to give the cropped shot the same shape as the originals. Drag to exclude the transparent edges. Click the tick to crop.

Select the highlights

Tick the eye icon to hide the top two layers. Click on the shadow.before layer. Grab the Magic Wand tool and set Tolerance to 35. Untick Contiguous. Click to select the over-exposed sky and other highlights. Shift-click to add missing bits of sky.

Combine the layers

Click Refine Edge and Set Feather to 1. Click OK. Tick the two hidden layers  eye icons. Click on highlight.before, then choose LayerLayer Mask Reveal Selection. The correctly exposed highlights on top will merge with the healthy midtones below.

Modify the mask

The arches look too dark. Grab the Brush tool and select a soft brush tip with a Size of 300. Set Opacity to 100%. Click on the Layer Mask. Set the foreground colour to black, then spray the arches to show the well-exposed tones from midtone_before.

Reveal shadow detail

Qick on the midtone.before layer and choose Layer>Layer Mask>Reveal All. Set Opacity to 35%. Click on midtone.before s Layer Mask and spray on the darker trees. This will make the layer become semi-transparent, showing lighter shadows from below.

Before and after

Shift-click on midtone.before s Layer Mask to temporarily disable it. A red cross will appear. Shift-click to re-activate the mask. The wind-blown leaves on the trees change position on each layer, but you shouldn t notice where the layers blend.

Tweak the colours7 Select the top layer, then choose Layer New I / Adjustment Layer Hue/Saturation. Set the menu to Cyans and increase Saturation to +30 for a more vibrant sky. Boost Blues to +16. You now have a composite shot with detail throughout the tonal range.

Finishing touch

On the Adjustment Layer, choose Shift+Ctrl+ Alt+E (Shift+Cmd+Alt+E on a Mac) to merge all layers into a flattened copy. Go to EnhanceAdjust Sharpness. Set Amount to 80% and Radius to 1. This teases out detail and gives more punch. Click OK.

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