Techniques

Quick and Flexible Black and White Conversion

by Tim Grey | November 1, 2006

© Tim GreyOne of the questions I get asked most frequently by nature photographers is how to make the best black and white images from color photographs quickly and easily. Most of the time “best” and “quickly and easily” are mutually exclusive, but fortunately there’s a way to perform a black and white conversion that provides both.

What I love about this method is that it provides results that are as good as the “best” method while not taking too much time compared to the “quickly” method. The best method involves using a Channel Mixer adjustment layer, adjusting the percentages of each channel (red, green, and blue) to provide the preferred final appearance for your monochrome result. This method works very well, but is somewhat complicated and is not exactly intuitive. The fast method is to simply convert the image to grayscale or reduce the saturation completely, but I would never recommend those methods as they offer no control over the result.

As I’m presenting this method, keep in mind that it sounds more complicated than it is. If you follow along you’ll see how it works, and after performing this black and white conversion a few times I think you’ll find it is indeed quick and easy while affording you great flexibility with the image.

The first step of this process is to make the image look monochromatic. Start by clicking on the top-most layer in the Layers palette to make it active. New layers are automatically placed above the currently active layer, and we want our new layers at the very top of the list.

Click on the “Create a new layer” button at the bottom of the Layers palette, which has a blank sheet of paper icon on it. This will create a new empty layer at the top of the stack. At first this layer won’t have any effect on your image, but that will quickly change. Select Edit > Fill from the menu, and in the Fill dialog box set the Use option to Black. Make sure the Mode is set to Normal and the Opacity is set to 100%. Click OK and the image will appear completely black, because this new black layer is covering up the image.

Fill dialog box Black layer
Fill dialog box Black layer

To see your image again, but now in a monochromatic version, you’ll need to change the way this black layer behaves. What we want is for it to only affect the color values, not the tonality, of the image below. To do so, click the blend mode dropdown at the top-left of the Layers palette (it has a default value of Normal) and change the option to Color. This will cause this black layer to only affect the color of the underlying image, effectively removing all color.

Layers - Color

You’ve now completed the first step, and have a monochromatic image. Now it is time to start exercising some control on the specific interpretation of the image to create the best starting point for your black and white result.

Click on the layer directly below the new black layer we just created, which may be the Background image layer or it may be another adjustment layer you had created before getting started with this black and white conversion. You need to select this layer so the next layer we add will appear directly below the new black layer we created.

Click on the “Create new fill or adjustment layer” button at the bottom of the layers palette. The icon on this button is a circle that is half black and half white, like a contrast knob. When you click on the button a list of available adjustment layers will appear. Choose Hue/Saturation from the list to create a new Hue/Saturation adjustment layer.

Now the fun begins. You can now quickly move through many variations on the black and white image by moving the Hue slider. There are 360 possible variations, since the Hue slider moves on a scale between -180 and 180. What you’re actually doing here is drastically altering the color appearance of the underlying image, but then putting that through a filter that shows it as monochromatic. By changing the relationships between colors, you’re also changing the relative luminosity of the various color areas in the image, producing a wide variety of options to choose from. You can also play with the Saturation slider a bit, which you can think of as being similar to a contrast control for this adjustment.

Creating a Hue/Saturation adjustment layer Adjustment layer selected
Creating a Hue/Saturation Adjustment Layer The Hue/Saturation Adjustment Layer

Peppers with Hue/Saturation palette

Settings adjusted

Once you’ve found the settings that work best for your image, click OK. You can then return to the top of your Layers palette and add Levels or Curves adjustment layers if you’d like to fine-tune the final black and white version of your image.

About the Author

Tim Grey is an educator in digital photography and imaging, offering clear guidance on complex subjects through his writing and speaking.

Tim has written more than a dozen books on digital imaging for photographers, has published dozens of video training courses, has had hundreds of articles published in magazines such as Digital Photo Pro and Outdoor Photographer, among others. For more than a dozen years he has been publishing the daily Ask Tim Grey eNewsletter, answering questions from photographers, and produces the related Ask Tim Grey Podcast. He also publishes the monthly Pixology electronic magazine, and publishes video training courses through GreyLearning.com. Tim teaches through workshops, seminars, and appearances at major events around the country and around the world.

Tim can be reached via email at tim@timgrey.com.

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