Top technology of black-and-white contrast mixing

Contrast is the most important factor in a good black-and-white photographic work. Images that lack contrast must be boring.

But it should be noted that if the contrast is too large, the details of highlights and dark parts will be lost. Because contrast has a great influence on the tone of an image, it is very important to control the contrast of a good black and white work.

Traditional photographers will use photographic paper with different contrast levels to adjust the contrast. If it is a soft and low contrast image, you will choose to enlarge it with 1 low contrast photographic paper; Gao Fancha's image will use No.5 Gao Fancha photographic paper.

In the digital age, there are many ways to adjust the contrast, and it has become simple. For example, using color scale and curve, the color scale adjustment is relatively extensive, and the curve adjustment seems to be the most flexible, but the selection of sampling anchor points is a test for the operator's vision and experience. Then the mixer changes the contrast, but this method is really too difficult for ordinary people to understand.

Beginners in Photoshop are often more willing to use the "brightness/contrast" method, but this adjustment is very rough and only beginners can do it.

Especially if you want to keep the natural color of the picture, you can only make minor adjustments. Increasing contrast will enhance the drama of the image at the same time, which is also the charm of contrast control of black and white tones.

In the last part of the lesson plan, a quick action of mixing black and white contrast with one key operation is added, which saves you tedious steps and settings. After importing a picture, you can get the perfect start setting by pressing a key, and all that remains is to drag one or two sliders to get the desired effect. At the same time with other Photoshop operations, it will get twice the result with half the effort.

There are some unfamiliar but equally effective ways to increase contrast. One of them is to change the mixing mode. Open the Layers panel and copy a layer. There are many mixed mode options here, but not all of them will increase the contrast. The modes that can improve the contrast include the following.

Check the "Monochrome" option in the dialog box, and then drag the sliders of the red, green and blue channels to adjust, and try to keep the sum of the three percentages equal to 100% (but it is not strictly stipulated). Below this value, supplementary details may be lost, and above this value, highlight overflow may occur. The Constant slider can increase or decrease the overall exposure, but it is too rough. Try not to use it.

In the Levels dialog box, move the Highlights and Shades sliders to the middle to increase the contrast of the picture. The most common problem is the 8-bit image, which is easily interrupted by color gradation processing, and the image will lose some information, which will affect the fineness of tone modulation. If you adjust it too much, it is easy to have color separation.

By increasing the slope of the curve to increase the contrast, we must pay attention to ensure the level of highlights and dark parts when adjusting.

Copying a layer and changing the blending mode to overlay is the best way to increase the contrast. You can also control the contrast by adjusting the opacity.

Most people with darkroom experience can easily understand this principle. This is by using different filters to achieve step-by-step exposure on the same film, thus applying different contrast to different areas. In a traditional darkroom, you can use the No.5 filter to get Gao Fancha, or you can use the No.0 filter to get low contrast.

However, it should be noted that the exposure results of the two operations have their own advantages and disadvantages: the result of Gao Fancha exposure is that the color contrast of the image is increased, but the details of highlights and dark parts are lost; However, warm light with low contrast will retain all tone levels, but it usually leads to insufficient contrast. The principle of "contrast mixing" is to combine the advantages of these two exposures, and at the same time foster strengths and avoid weaknesses, which not only increases the contrast, but also avoids the loss of highlights and dark details.

The later black-and-white picture digital processing code is also suitable for "contrast mixing". But it is much faster in Photoshop operation, so we can adjust it at any time and see the result immediately.

First, adjust the color image in ACR, which is the basis of all subsequent adjustments.

Print the image as a background layer in Photoshop. Then press "Ctrl+J" to copy a layer and name it "Saturation/Base".