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Lightroom and Photoshop offer an impressive array of tools for adjusting an image’s contrast. At some point luminosity contrast adjustment tips over to affecting image detail (contour and texture) more than overall lightness. Deciding exactly how you want to affect lightness, contour, and texture is the key to deciding which tool to use and how to use it.

The following progression moves from the smoothest to edgiest tools – Curves, Clarity, Dehaze, High Pass, and Sharpening. The differences between these tools can be found in the way they handle frequencies of detail; low or smooth, medium or broad lines and moderate texture, and high fine lines and grain.

01_Curves

Curves creates the smoothest effects. It simply affects light and dark values. With it you can fine tune the relationships between different values with unparalleled precision. Curves ignores texture and contours. If either is affected it’s simply because those areas are lighter or darker, not because they have been targeted. Along with contrast, Curves also boosts saturation somewhat. (If Curves is applied in Photoshop, this saturation shift can be removed by using a blend mode of Luminosity.)
02_Clarity

Clarity offers the second smoothest effects. It pays significant attention to contours. The contrast it adds to contours is smoothed or broadly feathered. Think of it as a local vignetting, not for the frame, but for areas within contours. To make the effect more realistic, it darkens the dark side of contours more than it lightens the light side of contours edges, greatly reducing visible bright halos. Clarity makes images look clearer for two reasons; one, because the overall contrast appears to remove haze; and two, because the edge contrast makes images appear better focused or sharper. Clarity, particularly strong applications of it, will accentuate texture affecting medium frequency detail even more than high frequency detail. Strong applications of Clarity will boost saturation significantly, which can be removed with the Saturation slider. Clarity does not exist in the Photoshop Image > Adjustments menu but can be applied in Photoshop with the Camera Raw filter.

03_Dehaze

Dehaze offers the third smoothest effects. It creates effects that are similar to Clarity, only stronger. Dehaze darkens shadows and rather than brightening the highlights it simply pulls out more separation by darkening the lower values in these areas. Strong applications of Dehaze may even reveal detail you can’t see with the naked eye. Dehaze affects larger areas of contrast, sometimes losing the ability to distinguish between smaller areas. While Clarity boosts saturation somewhat, Dehaze boosts it more and often creates color non-uniform shifts. (There is a cure for this, which I cover in a separate article.) Dehaze does not exist in the Photoshop Image > Adjustments menu but can be applied in Photoshop with the Camera Raw filter.
04_HighPass_HighHigh Pass High
05_HighPass_Low

High Pass Low

High Pass filtration drives contrast into edges. It produces significantly different effects at low and high settings. At low settings it affects contours most, only slightly affecting texture and having little or no effect on overall contrast. At high settings it produces localized vignetting similar to Clarity but with less feathering, making it an excellent tool for emphasizing planar contrast. Be careful, it does not have the halo suppression built into Clarity. Only high settings create saturation shifts, which are localized not uniform. Remove this by desaturating the layer you apply the filter to. The High Pass filter is only available in Photoshop and is usually applied on a duplicate layer set to a blend mode of Overlay.

06_Detail

The Detail Panel’s Sharpening sliders aggressively target edges. It offers four sliders – Amount, Radius, Detail, and Masking. Amount determines the increase in contrast. Radius accentuates contours in thinner (lower setting) or thicker (high setting) areas. Detail targets the effects of the previous two sliders into lower (less texture) or higher (more texture) frequencies of detail. Masking creates a mask that removes the effects of the other sliders from smooth areas at low settings and from all areas but contours at its highest settings. These sliders produce no overall contrast effects and little to no saturation shifts. (These detail sliders don’t exist in the Photoshop Image > Adjustments menu. Photoshop’s filter Unsharp Mask offers identical Amount and Radius sliders but it lacks the Detail and Masking sliders. Instead, it offers a Threshold sliders that allows you to remove the effect from adjacent areas that have less contrast than the Threshold you set.) These tools are the ultimate tools for accentuating texture and contour.

Experiment. Develop your eye for all of the possibilities these tools open up for you. You’ll be amazed what they can do. And when you master them, your viewers will be amazed at how good your images look.

Read more on Color Adjustment here.

Learn more in my digital printing and digital photography workshops.

View test files with maximum applications of these tools below.

Read more

BeforeAfter

There are many things you can do in Photoshop to make the most of shadow and highlight detail in images, even if you didn’t bracket exposures for HDR.

Curves

Curves, the most precise tool for modifying brightness and contrast, allows you to target and adjust shadows and highlights independently of one another. You can use it to reduce contrast and render more detail in very bright highlights and/or very dark shadows. The Curves interface has a feature (The icon looks like a finger with up and down arrows.) that allows you to click on any area of an image to place a point and adjust those values. If you’re adjusting highlights and shadows, it’s quite likely that you will also have to adjust values in the other end of the tonal scale and possibly midtones to generate the best results. Keep it simple; it’s surprising what you can do with just two or three points. Keep it smooth; avoid posterization by not flattening areas of a curve. The Blend Mode Luminosity can be used to remove any unintended shifts in saturation; more contrasti increases saturation while less contrast decreases saturation.

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Curves can be used to lighten shadows and/or darken highlights

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Before Curves

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After Curves

Shadows/Highlights

The Shadow / Highlight feature in Photoshop (Image > Adjustments > Shadow Highlight) can be very useful for more challenging images. It cannot be applied as an adjustment layer but it can be applied as a smart filter. To preserve future flexibility, apply Shadows / Highlights applied to the Background Layer converted to a smart object or to a duplicate Background layer if you plan to use Blend If sliders.

At first glance, Shadows/Highlights appears to offer two simple Amount sliders. Check Show More Options and you’ll find more sliders. The Tonal Width slider specifies which values are and are not affected, similar to a luminance mask. The Radius slider applies a sharpening affect, similar to High Pass filtration, to the affected areas only; this is the slider that does what no other tool does. Additionally, you can apply Color and Midtone adjustments – but there are other better ways to do this.

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The Radius slider in Photoshop’s Shadows/Highlights provides affects not found in other tools

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Before Shadows/Highlights

after_AntXL

After Shadows/Highlights

Screen / Multiply

You can make industrial strength adjustments to an image using the Blend Modes Multiply and Screen found in the Layers palette. (Use the pull down menu that defaults to Normal.) Multiply dramatically darkens an image; it’s like registering two transparencies on a light table. Screen dramatically lightens an image; it’s like registering two projected images on a wall. These effects can be very helpful in making very bright highlight and very dark shadow detail more visible. Blend modes can be applied with any layer. They can be combined with Curves adjustments for even stronger effects. Because their effects are so strong you’ll want to modify their intensity using the Opacity slider or restrict their effects using Blend If sliders or a contrast mask.

Read more about Photoshop Blend Modes here.

Blend If Sliders

To restrict an adjustment to either the shadows, midtones, or highlights, you can use the Blend If sliders found in the Layer Style menu. Double click on the layer (Not the icon or the name, but the area to the right of them.) to activate the Layer Style menu. Then use the sliders in This Layer to remove the effect on the background layer. For smoother transitions, feather the effect by holding the Option/Alt key and splitting the sliders apart.


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T Layer Style dialog with Blend If sliders set to target shadows

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The Layer Style dialog with Blend If sliders set to target highlights

Luminance Masks

To more precisely target a specific range of the tonal scale, you can quickly make precise luminance masks in Photoshop. Simply go to the Channels palette and Command/Control click on the RGB channel. This will load a selection of the highlights. If you want to create a selection of the shadows go to the Select menu and choose Inverse. Then simply make an adjustment layer and the selection will automatically become a mask or target a layer and click the mask icon at the bottom of the Layer palette. You can further modify the brightness and contrast of the mask by applying Curves to it (Image > Adjust > Curves).

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Highlight mask shadowmask

Shadow mask

Read more about luminance masks here.

Blending Channels

Do you still want more? If dynamic range issues persist in one channel (or even two), you can use the information in the other channel(s) to improve it. Use Photoshop’s Channel Mixer or use a duplicate layer’s Layer Styles. It’s a complex technique, but it’s there when you really need it.

Read more about blending channels here.

For even more dramatic effects these methods can be used in combination with one another.

To Merge Or Not To Merge

All of this might make you wonder why you’d ever need to bracket exposures for HDR merges. Actually, there are plenty of times – when the dynamic range of a scene far exceeds the dynamic range of a camera’s sensor. You can use all of these techniques in combination with HDR merges to get optimum results. Knowing why and why not to use HDR merges, when and when not to use them, and how far to go or not go with them will help you master them.

Read more on HDR techniques here.

Learn more in my digital printing and digital photography workshops.


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