Set your White and Black Point – Digital Photography Tip of the Week

There are a few steps I do to almost all of my images after I have captured them. Over the next couple of weeks, I will go over some of them, step by step.

The first step to obtaining a great final image is setting your black and white points. Most, but not all photographs can be improved by modifying how the tones are represented in the image by adjusted the brightest parts of the image to pure white and the darkest to pure black, or very close.

In this first image, you can see how the image looked before any modifications to the image were made. The photo does not have a lot of impact, lacks the white tones we expect to see from a scene with snow and even the shadows lack impact. The first step to setting your black and white points is to create a Levels adjustment layer which I have begun to do on the right. Adjustment layers let you modify your image without changing the actual pixels. This is an important step to a good digital workflow as it allows you to make changes later to the decisions you make now on how you want your image to look. Also, your final image will be of better quality because you will only make one change to your image data instead of many. To add a Levels adjustment layer, click on the black and white circle above the layer in your layers palette (F7) and choose Levels …

Before setting white and black points.

The Levels dialog box shows a histogram which displays visually in graph form where the tones in your image fall between black and white. Points on the left of the graph represent the dark tones of your images and points on the right represent the white tones of your image. To set the white point, simply slide the white arrow below the graph to the left. As you do so, your image will change to reflect the adjustment you are making. Holding down the ALT key on your keyboard can aid in deciding where to place your whites. When you hold the ALT key down, the image will turn black and as the slider is moved to the left, the pieces of of your image that are clipped to pure white will turn white. You may also see other colours, red, green and blue representing one or more channels of the image being clipped. If you let go of the ALT key, you can see the image with it’s white point set.

Setting the whitepoint for your image

Similarly, holding the ALT key and clicking on your black point slider will turn the image white and then the areas black as they are clipped. While the ALT method is a good indicator of where pure white and pure black will appear in your photograph, it is still best to visually determine where you want white and black. With this photo of drifting snow, the shadows of the drifts would be the first areas to become pure black, but that change would not help this particular photograph as it does better without a pure black in the photo. A word of caution: areas that have been clipped will not contain any texture, only a solid white or black and so should be selected carefully.

Setting the black point for your image

The final image as shown above now shows whiter whites and more natural shadows. A more pleasing image all around. There is still texture in the whites of the middle ridge and the only area’s being completely clipped in this image are the specular highlights in the snow that do not show up in this small image.

Next week I will discuss using layer masks for selective editing.

I will be at the Holiday Inn on Grand Island, NY this weekend attending the annual Niagara Frontier Regional Camera Clubs convention. Featured speakers include Darrell Gulin, Jack Graham, Patti Rusotti and other. We have a great line up for the weekend and tickets are still available. For more information, visit the NFRCC website.

Until next time, happy shooting.

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