Sometimes it’s easier to make a selection of an object if the contrast between the subject and the background is greater. In order to temporarily add more contrast, try adding an adjustment layer (such as Curves or Levels), and boost the contrast significantly. Then, then make the selection and, when finished, discard the adjustment layer.
Posts tagged "Adjustment Layers"
In a recent presentation I was asked to share some “lesser” known features from Photoshop CS5. I have noted all of the following in my blog at some point, but here are a dozen of my favorites all together:
1) Changing Brush Size – With a painting tool selected, Control + Option (Mac) – drag left/right in order to decrease/ increase brush size. To decrease/ increase brush hardness, drag up/down. On Windows, Shift + Alt -drag left right to decrease/ increase brush size and up/down decrease/ increase brush hardness.
2) On Screen Color Picker – To access the new HUD color Picker, with a painting tool selected, Control + Option + Command (Mac) -click and drag to select a color. On Windows, Shift + Alt + right-click and drag to select a color. Or, if that shortcut is too much to remember, to display the color picker using a keyboard shortcut, choose Edit > Keyboard Shortcuts. Under the Shortcuts for “Tools” scroll to the bottom to locate the “Foreground Color Picker ” line item and enter in your own custom keyboard shortcut.
3) The Eyedropper Tool – Clicking in the image area with the Eyedropper tool now displays a sample ring. The “new” color (the one being sampled) is displayed in the upper half of the ring while the current (or foreground color before sampling) is displayed in the bottom half. The ring is surrounded by grey to help neutralize surrounding colors that may influence color choices. The sample ring can be toggled off/on by unchecking/checking Show Sample Ring in the Options bar. Or, if you’re an avid user of Tool presets, make one with the ring turned on, the other with it off. In addition Control (Mac) / Right Mouse (Win) -click to select the Sample Size or Copy the Color as Hex Code or HTML
4) Scrubby Zoom – With the Zoom tool selected, click-drag to the right to zoom in, click-drag to the left to Zoom out. This new feature adds the benefit of being able to quickly zoom in AND zoom out to a specific location, however, if you prefer the legacy behavior (click-drag over the area to zoom into), disable Scrubby Zoom in the Options Bar. In addition, when viewing multiple images simultaneously, Shift -drag with the Hand tool to pan all open documents. Similarly, shift -clicking with the Zoom tool will zoom all images simultaneously. To set this as the default behavior, with the Zoom or Hand tool selected, check the “Zoom all Windows” and/or “Pan all Windows” in the Option bar.
5) Saving 16 Bit Images as JPEG – If you’re working with 16 bit files and want to save them as a JPEG, you can now select the JPEG file format from the list in the Save As dialog box. However, you need to know that saving as a JPEG will convert the file from 16 bit down to 8 bit (as the JPEG file format does not support 16 bit). Note: it is also important to note if you’re saving a layered file as a JPEG, Photoshop will flatten the file as the JPEG file format does not support layers.
6) Saving Files to Their Original Folders – By default, when saving files, Photoshop will automatically navigate to the folder where the last file was saved. To save files to their original folder, select Preferences > File Handling > and check on the “Save As to Original Folder” option.
7) Auto-Select Parameter for Adjustment Layers – In order to automatically put the keyboard focus onto the first field in the Adjustment panel, use the fly out menu in the Adjustments panel, and select Auto-Select Parameter (this behavior was added as it is similar to the legacy way of working with image adjustment dialog boxes – as oppose to the adjustment panel). Return (Mac) / Enter (Win) + Shift is another way to put the keyboard focus onto the first field in the Adjustment panel. You can also use a keyboard shortcut to select the Targeted Adjustment Tool while using a Hue/Saturation, Curves, or Black & White adjustment layer, choose Edit > Keyboard Shortcuts. Under the Shortcuts for “Tools” scroll the towards the bottom of the list to locate the “Targeted Adjustment Tool” line item and enter in your own custom keyboard shortcut.
8)The Crop Tool Overlay – With the Crop tool selected, drag out the crop marquee and then, in the Options bar, choose Between Rule of Thirds, Grid or None for the Crop Guide Overlay. Note, you must first drag out the crop in the image area for this setting to appear in the Options bar.
9) Control Change the Opacity/Fill of Multiple Layers – Simply select multiple layers in the Layers panel and use the Opacity and/or Fill slider to change the Opacity/Fill of all selected layers at once.
10) Layer Styles – In order to customize the default Layer Style settings, select Layer > Layer Style (or click the fx icon at the bottom of the Layers panel). In the Layer Style dialog, make the desired changes, and click the Make Default button. If you make changes to the style and want to reset the changes to your custom default, click the Reset to Default button.
11) Panorama Stitching – When using the Auto-Align Layers command Photoshop now leverages lens correction profiles (if applied).
12) Non-rotating Brushes with Rotate View – When using the Rotate View tool to rotate the canvas for easier drawing and painting, the brushes will no longer rotate with the canvas rotation; instead they remain at the orientation of the original artwork regardless of the viewing angle.
In this episode of The Complete Picture, I will demonstrate how to reduce the color palette of an image to create a posterized effect with the most control and maximum flexibility possible.
A great way to ensure that a change you make to an image is only affecting the tonal (not color) values is to set the blend mode to Luminosity. For example, if you have an area in an image that is too dark and you want to lighten it without changing the colors, add a Curves Adjustment Layer and set the blend mode to Luminosity. Then raise or lower the curve as necessary – without affecting the color values. This can be especially helpful when dodging or burning skin-tones. If you want to affect the colors and not the tonal values, simply change the blend mode to color.
Layer Groups have a unique blend mode called Pass Through which is only visible when a Layer Group is targeted in the Layers panel. It allows any adjustment layers, blend modes, advanced blending options, opacity and fill values applied to layers within a Group, to affect layers below the Group in the layers panel. To restrict the blending of layers to only happen within a Group, change the Layer Group’s blend mode to Normal.
The sixth group of Blend modes have no neutral colors. They work in a hue, saturation, luminance space that is similar to but different from both HSB and HSL. In particular, while hue is the same in all three spaces, all of the spaces define saturation and brightness/lightness/luminance somewhat differently. All of the combinations described below are subject to clipping to keep the values in the valid RGB range.
• Hue – Creates a result color with the luminance and saturation of the base color and the hue of the blend color.
• Saturation – Creates a result color with the luminance and hue of the base color and the saturation of the blend color. Painting with this mode in an area that has no (0) saturation (gray) causes no change.
• Color – Creates a result color with the luminance of the base color and the hue and saturation of the blend color. This preserves the gray levels in the image and is useful for coloring monochrome images and for tinting color images. Color yields a result with the same hue and saturation as the upper color and the luminance of the lower color.
• Luminosity – Creates a result color with the hue and saturation of the base color and the luminance of the blend color. This mode is the inverse of Color mode.
One of the common uses of the Color blend mode is for selective coloring effects using the painting tools, gradient fill layers and layer effects. For example, you can select the paint brush, set its blend mode to color and paint directly on an image (but this isn’t very flexible if you make a mistake). For more flexibility, you can choose to create a new layer and set it’s blend mode to Color and set the paint brush’s blend mode to Normal to paint any part of an image.
Difference, Exclusion and Subtract have a neutral color of black. This means that black as a blend color will have no effect on the result color. The Divide blend mode has a Neutral color of white.
• Difference – Looks at the color information in each channel and subtracts either the blend color from the base color or the base color from the blend color, depending on which has the greater brightness value. Blending with white inverts the base color values.
• Exclusion – Creates an effect similar to but lower in contrast than the Difference mode. Blending with white inverts the base color values. Blending with black produces no change. The effect is a bit like using one image to solarize the other.
• Divide and Subtract – Both are intended for us with calibrated imaging however interesting creative effects are also possible. For astronomy and microscopy: you want to subtract background values (dark frames, factoring out hot pixels, etc.), and divide by a flat field image (removing vignetting and other lens defects, bringing insensitive pixels back up to normal range, etc.). You can remove lens falloff even if you have something that Lens Correction can’t handle (like mirror lenses, dust on the lens, etc.). Of course you can also use them for HDR toning tricks (or experimentation). Martin Evening has posted an excellent tutorial on these two new blend modes. Click here to read more…
The fourth group of Blend modes have a neutral color of 50% gray. This means that 50% gray as a blend color will have no effect on the result color. All of the light modes (except for Hard Mix) lighten when using colors brighter than 50% gray and darken when using colors darker than 50% gray. This happens on a channel-by-channel basis so they can actually both lighten and darken at once.
• Overlay – Multiplies or screens a scaled version of the blend color into the base color based on whether the lower color is darker or lighter than 50% gray. Colors darker than 50% are multiplied, colors lighter are screened. Patterns or colors overlay the existing pixels while preserving the highlights and shadows of the base color. The base color is not replaced but is mixed with the blend color to reflect the lightness or darkness of the original color.
• Soft Light mode – Darkens or lightens the colors, depending on the blend color. If the blend color (light source) is lighter than 50% gray, the image is lightened as if it were dodged. If the blend color is darker than 50% gray, the image is darkened as if it were burned in. Painting with pure black or white produces a distinctly darker or lighter area but does not result in pure black or white. It uses gamma adjustment s to darken or lighten. The effect is similar to shining a diffused spotlight on the image.
• Hard Light – Multiplies or screens the colors, depending on the blend color. If the blend color (light source) is lighter than 50% gray, the image is lightened, as if it were screened. This is useful for adding highlights to an image. If the blend color is darker than 50% gray, the image is darkened, as if it were multiplied. This is useful for adding shadows to an image. Painting with pure black or white results in pure black or white. The effect is similar to shining a harsh spotlight on the image.
• Vivid Light – Burns or dodges the colors by increasing or decreasing the contrast, depending on the blend color. If the blend color (light source) is lighter than 50% gray, the image is lightened by decreasing the contrast. If the blend color is darker than 50% gray, the image is darkened by increasing the contrast. Vivid Light uses color burn and color dodge to darken or lighten.
• Linear Light – Burns or dodges the colors by decreasing or increasing the brightness, depending on the blend color. If the blend color (light source) is lighter than 50% gray, the image is lightened by increasing the brightness. If the blend color is darker than 50% gray, the image is darkened by decreasing the brightness. Linear Light uses linear burn and linear dodge to darken or lighten.
• Pin Light – Replaces the colors, depending on the blend color. If the blend color (light source) is lighter than 50% gray, pixels darker than the blend color are replaced, and pixels lighter than the blend color do not change. If the blend color is darker than 50% gray, pixels lighter than the blend color are replaced, and pixels darker than the blend color do not change. Pin Light uses darken or lighten modes to darken or lighten. This is useful for adding special effects to an image.
• Hard Mix – Lighter colors lighten the result. Darker colors darken the result. Lowering the fill opacity creates less posterization/thresholding.
The third group of Blend modes have a neutral color of black. This means that black as a blend color will have no effect on the result color. These blend modes all have stronger effects as the blend color becomes lighter. Using the Fill slider on Layers palette and using blend modes from this group may modulate this effect rather than performing a simple opacity blend the way normal mode does. The lightening modes are essentially the inverses of the darkening modes.
• Lighten – Looks at the color information in each channel and selects the lighter of the base or blend color as the result color. Pixels darker than the blend color are replaced, and pixels lighter than the blend color do not change.
• Screen – Looks at each channel’s color information and multiplies the inverse of the blend and base colors. The result color is always a lighter color. The effect is similar to projecting multiple photographic slides onto the same screen. Screen reduces contrast and can produce and effect similar to painting an area with bleach.
• Color Dodge – Looks at the color information in each channel and brightens the base color to reflect the blend color by decreasing the contrast. Color Dodge is an exception to the neutral color rule in this group – it is the only lightening mode that preserves blacks. Color Dodge is similar to moving the input white triangle in Levels. As such, color dodge increases contrast but may clip the brighter portions of the lower colors to white.
• Linear Dodge – Looks at the color information in each channel and brightens the base color to reflect the blend color by increasing the brightness. Linear dodge is the combination of color dodge and screen. As such, it has a stronger lightening effect than either of them. Linear Dodge will clip bright values, unlike Screen.
• Lighter Color Compares the total of all channel values for the blend and base color and displays the higher value color. Lighter Color does not produce a third color, which can result from the Lighten blend, because it chooses the highest channel values from both the base and blend color to create the result color.
The second group of Blend modes (Darken, Multiply, Color Burn, Linear Burn and Darker Color) have a Neutral color of white. This means that white as a blend color will have no effect on the result color (white simply disappears). These blend modes all have stronger effects as the blend color becomes darker. Using the Fill slider on Layers palette using blend modes from this group may modulate this effect rather than performing a simple opacity blend the way normal mode does. By definition:
• Darken – Looks at the color information in each channel and selects the darker of the base or blend color as the result color. Pixels lighter than the blend color are replaced, and pixels darker than the blend color do not change.
• Multiply – Looks at the color information in each channel and multiplies the base color by the blend color. The result color is always a darker color. Multiplying any color with black produces black. When you’re painting with a color other than black or white, successive strokes with a painting tool produce progressively darker colors, producing an effect similar to drawing on the image with multiple magic markers. Multiply is a bit like sandwiching two chromes and projecting them together.
• Color Burn – Looks at the color information in each channel and darkens the base color to reflect the blend color by increasing the contrast. The result will always be darker and have more contrast.
• Linear Burn – Looks at the color information in each channel and darkens the base color to reflect the blend color by decreasing the brightness and – unlike multiply – it will clip values while doing so. It has a stronger darkening effect than either multiply or color burn. Linear Burn is a combination of color burn and multiply.
• Darker Color – Compares the total of all channel values for the blend and base color and displays the lower value color. Darker Color does not produce a third color, which can result from the Darken blend, because it chooses the lowest channel values from both the base and the blend color to create the result color.
In previous posts, I have covered the shortcuts to change blend modes, and as a result, I have had several people request more detailed information about each blending mode so lets get started.
First some basic information – a blend mode allows you to control how the pixels on one layer work with or affect (or blend with) other pixels in Photoshop. They can be found throughout the program in such areas as the Layers panel, Layer Styles, the Fill, Stroke and Fade commands, the Painting tools, and Apply Image and Calculations commands. Within each of these different areas of the program, the blend modes which are available vary based on which modes are useful and appropriate for each command. Except where noted, these modes work on a per channel basis — i.e., they treat an RGB image like three grayscale images.
When using blend modes, it’s helpful to think of the effects in terms of the following three colors:
• The base color is the original color in the image (which can be the color on a layer or a cumulative combination of layers).
• The blend color is the color being blended (the painting or editing color).
• The result color is the color resulting from the blend.
Note – some of the blend modes have what are called Neutral colors, or colors that have no effect when they are blended. For example, Multiply has a Neutral color of black, and Screen’s neutral color is white – but I’m getting ahead of myself…
The first grouping of blend modes contain from one to four blend modes depending on the feature: Normal, Dissolve, Behind and Clear. Note: the Fill command and the painting tools are the only ones that list the Behind and Clear blend modes. In this grouping, there is no Neutral color – all blend colors will effect the base colors. When used at 100% opacity, the blend color will replace the base color. I point out that I’m using 100% because lowering the opacity of the layer (or paint or fill etc.) will change the way that the blend color is combined with the layer below. By definition:
• Normal – This is the default mode. Pixels don’t blend. Results are as expected – you choose red to paint with, and you get red. You put a photo on a layer and it is displayed as the original photo obscuring any layers beneath it. As expected. (Under the hood, this mode edits or paints each pixel to make it the result color. Note: Normal mode becomes Threshold when you’re working with a bitmapped or indexed-color image.)
• Dissolve – Edits or paints each pixel to make it the result color; however, the result color is a random replacement of the pixels with the base color or the blend color, depending on the opacity at any pixel location. Lowering the opacity (in this case the opacity of the Layers palette) reveals a speckled effect which is either the blend color or the base color – never a combination of the two. I’ve seen this blend mode used effectively when creating a stippled effect with the paintbrush and a large brush (see illustrations below).
• Behind – Edits or paints only in the transparent areas of a layer. This mode is available for the painting tools and the Fill command. It’s like painting on the back side of acetate, underneath the image. Note: this mode works only in layers with Lock Transparency deselected (that little checkerboard icon to the right of the word Lock on the Layers panel).
• Clear – Makes all affected pixels transparent – essentially the same result as using the Eraser tool. This mode is available for the painting tools, the Fill command, and the Stroke command. Note: you must be in a layer with Lock Transparency deselected to use this mode.
When refining changes (moving settings) made with an adjustment layer, hold the “\” (backslash) key to toggle between the before state (when you started making changes) and the current state (the changes you’ve made).
There are times when you will want to use Image > Adjustments > Curves to modify an image instead of using an adjustment layer. This is true, for example, when adjusting a mask. The following shortcuts are handy when navigating the Curves modal dialog box. Note: these shortcuts are not always the same when using the Adjustments Panel to modify a curves adjustment layer.
Command (Mac) / Control (Win) + M displays the Curve Dialog Box
Command Option (Mac) / Control Alt (Win) + M displays the Curves dialog with the last used settings
With the on-image adjustment button (also known as the targeted adjustment tool or scrubby slider) off:
Command (Mac) / Control (Win) -click the image to add a point to the active curve only.
Command (Mac) / Control (Win) +Shift to add a point to all of the channels.
Shift -click in the image area to add Color Sampler point.
Option (Mac)/ Alt (Win) + Shift -click on a color Sampler point to delete it.
Click -drag on image to display a small dot on the curve corresponding to the value clicked upon.
Control (Mac) + tab and Tab (Win) will toggle focus from one point on the curve to another (as will the + and – keys).
Shift click to select multiple points on the curve.
Command (Mac) / Control (Win) + Delete to delete a point.
Use the arrow keys to move the select point one increment. Add the Shift key to move in greater increments (10).
Option (Mac)/ Alt (Win) + drag the black/white point sliders to display shadow/highlight that will be clipped to pure black/white.
Option (Mac)/ Alt (Win) + click the grid to toggle size.
Option (Mac)/ Alt (Win) + P toggles Preview on and off.
In the Levels, Curves, and/or Black and White Adjustment panel, Option (Mac)/ Alt (Win)-click the Auto button to display the Auto Color Corrections Options.
With the on-image adjustment button (also known as the targeted adjustment tool or scrubby slider) off, and the eyedropper tool on:
Command (Mac) / Control (Win) -click the image to add a point to the active curve only.
Command (Mac) / Control (Win) +Shift to add a point to all of the curves (channels).