Black & White
In previous versions of Photoshop, the most common method for converting a color image to black & white was to use the Channel Mixer. It was a clunky, counter-intuitive process that forced you to think like Photoshop instead of allowing your brain and eyes to naturally digest what was being done to your image. The new Black & White converter is a truly wonderful tool that makes the conversion process much more intuitive and user friendly. Because it’s so easy to use, it’s got an instant gratification aspect to it that makes it especially fun to play with.
Creating a Good Mix
When you choose Image>Adjustments>Black & White, all the color will be taken out of your image and you’ll be presented with a dialog box that has six primary sliders. You can control the brightness of different areas in your image by dragging the appropriate slider (for instance, the Reds slider brightens or darkens areas that used to be red in the image). The only problem with this approach is that you can’t see what color different areas used to be without toggling the Preview checkbox.
You can also click and drag within the main image window to have Photoshop try to figure out the proper slider to affect that area. When working this way, click on the image and (while you’re still holding down) simply drag to the left to darken the area, or drag to the right to brighten it. You’ll see the corresponding slider magically move in the Black & White dialog box. I absolutely love working this way, but find that Photoshop doesn’t always choose the best slider to isolate the area on which I’m clicking. If you find that it’s having trouble isolating an area, toggle the Preview checkbox off and then back on again and try the sliders in an area similar in color to the area you want to affect. You might find that one chosen manually in this fashion works better than the one that Photoshop automatically selects.
In this example, dragging on either the body of the car or the fender area caused Photoshop to move the Reds slider which caused both areas to change in almost equal amounts. By experimenting, I found that the Yellows slider did a much better job of isolating the body of the vehicle, so I used the Yellows slider to brighten the body and the Reds slider to darken the fender of the car.
Watch Out For Clipping
Each of the adjustment sliders in the Black & White dialog box has a very wide range available, which means that it’s very easy to end up with solid black or white areas in your image (also known as clipping). If you’re concerned about losing detail in the highlight or shadow areas of your image, consider opening the Info palette (by choosing Window>Info) and passing over the brightest and darkest areas of the image. If the right side of the RGB readout in the Info palette ever hits zero, you’ll know that the area under your mouse is solid black and if it hits 255, then the area is white. I find that turning on the Tint checkbox (which we’ll discuss next) can make it easy to tell if you’re losing highlight detail. That’s because the white areas will contrast with the areas that are being tinted, thus making them easier to see.
Adding a Color Tint
Photographers often add a very subtle hint of color to their black and white conversions to make them feel slightly warm or cool. You can do this to your black & white conversions by turning on the Tint checkbox in the Black & White dialog box. The Hue slider will determine the color used and the Saturation slider will determine the amount of color used.
You can also specify the color by clicking on the color swatch that appears to the right of the Hue and Saturation sliders. If there are particular colors that you prefer to use, consider either saving them as part of a preset (mentioned below), or save the colors into the Swatches palette so you can easily access them in the future. When you want to apply one of the colors, click on the color swatch to the right of the Hue and Saturation sliders to access the color picker and then click on one of the colors in the Swatches palette while the picker is still open.
Working with Presets
I find that there are certain starting points I prefer when working on different types of images. For landscapes, I might want to make the blue darker to get a nice rich looking sky, while lightening the yellows to get good looking grass and trees (these areas typically contain more yellow than green). For portraits, I might prefer to have lighter yellows, reds and magentas to keep the skin on the pale side while darkening the greens, cyans and blues to contrast them with the skin. You’ll have to experiment to figure out what works best for your particular situation. Once you’ve come up with some good starting points for different types of images, you can save them as presets by clicking on the icon that appears to the left of the OK button and choosing Save Preset. If you assign it a name and save it in the default location, you’ll be able to quickly access it in the future by choosing its name from the Preset pop-up menu at the top of the Black & White dialog box.
Tips & Tricks for B&W Conversions
Below are a selection of tips and insights that I think you’ll find useful when making black & white conversions:
True Grayscale: Applying a Black & White adjustment does not automatically convert your image to grayscale mode. RGB images take up three times as much space in memory and on your hard drive, so if you want to end up with the most efficient file size, choose Image>Mode>Grayscale after converting your image to black & white.
RGB Only: The Black & White adjustment does not work on CMYK or Lab mode images. Choose Image>Mode>RGB if you find that the Black & White menu item is not available.
Muted or Low Contrast Originals: If your original image contains mostly muted colors or does not have much contrast, try Image>Adjustments>Auto Levels before applying a Black & White adjustment. That should help to produce better separation between the colors in your image.
Auto for Actions: Click on the Auto button in the Black & White dialog box to have Photoshop analyze your image and move the sliders to add contrast. Don’t expect this to give you the best results though. It’s simply better than the default settings and might be useful if you need to quickly convert dozens of images using an action. When recording the action, just click the Auto button and don’t mess with any of the color sliders (otherwise it will record the position of all the sliders instead of the Auto button).
Maximum RGB: You can have Photoshop use the highest value of the red, green and blue numbers that make up each pixel in an image (essentially grabbing the brightest pixel from each of the channels that make up the image). That means Photoshop would analyze an area that contains 100R 200G 50B, and choose the 200 value to use for all three colors (since balanced RGB is needed to produce a shade of gray). For the maximum RGB value, set all the color sliders to +100.
Minimum RGB: Another alternative method of converting to black & white is to use the lowest RGB number for each pixel. To get an image with the minimum RGB values, set all the color sliders to zero.
Straight Red, Green or Blue: You can perform a direct conversion of one of the RGB color channels in your image to a black and white image by doing the following: for the Red channel, set the Red, Yellow and Magenta sliders to 100% and all the others to zero. For the Green channel, set the Green, Yellow and Cyan sliders to 100% and the others to zero. For the Blue channel, set the Blue, Cyan and Yellow sliders to 100% and all the others to zero.
Keyboard Shortcuts: If you’re a keyboard shortcut junkie, type Shift-Option-Command-B (Mac), or Shift-Alt-Ctrl-B (Win) to access the Black & White adjustment dialog box. If you prefer to use Adjustment Layers, consider assigning its keyboard shortcut (via the Edit>Keyboard Shortcuts menu) to the Layer>Adjustment Layers>Black & White command so that it will produce an Adjustment Layer.