Post-processing of digital photos can be divided into two stages. In the first stage, the digital photos can be accurately restored to the way they were seen by human eyes at the time; in the second stage, some special processing can be performed on the photos, adding special effects, synthesis, etc. If you want to learn digital photo post-processing well, you must start from the first stage. Since the Raw format electronic negative retains the original information of the photo to the maximum extent, it is most suitable for post-processing and restoring human vision with high fidelity.
This article will discuss with you some of the most basic methods and techniques for processing Raw format photos with Photoshop.
1. Use ACR to build a digital darkroom
There are many softwares that can process Raw photos, but I think Adobe Camera Raw (ACR) is the most suitable for beginners. The software interface is shown in Figure 1.
The advantage of ACR is that it is a plug-in, which comes with Photoshop CS3 and above, and is seamlessly integrated with Photoshop. The simple operation interface and reasonable division of functional areas make ACR easier to use. It meets the high requirements of professional players for image processing quality and is also suitable for entry-level players who require simple and fast image processing.
2. Multi-format output of photosAfter processing electronic negatives in Raw format, we generally output them into JPG, TIFF and other formats for easy viewing and printing. In ACR, just follow the steps below.
Start Photoshop and drag a Raw file icon into the window. ACR will automatically run and open the Raw file. The interface is as shown in Figure 1. Click the "Save Image" button on the lower left and a dialog box will pop up. As shown in Figure 2, in the "Format" option on the lower left, we can set the format of multiple output images.
3. Practical practice of developing Raw landscape films
Beautiful scenery is what everyone likes to shoot. The general process of processing landscape photos is:
Adjust white balance → Correct exposure, contrast, shadows, highlights → Correct and adjust color → Sharpen pictures and reduce noise → Crop and other modifications → Output pictures
Below we use a typical case to introduce the basic techniques of developing Raw films with ACR. Figure 3 is a Raw electronic negative showing the scenery of Tibetan houses in Shangri-La.
There are several main problems with this photo:
●White balance fails to reflect the light characteristics at dusk ●Underexposure, insufficient contrast ●Plain colors ●Insufficient sharpness and softness
Don’t worry, ACR can easily solve these problems, let’s do it together.
1. Lossless image quality correction white balance
In order to restore the dusk light conditions when shooting, we first correct the white balance of the picture. The command slider at the top of the ACR software is the white balance correction tool (Figure 4). It provides two adjustment sliders and a preset white balance mode drop-down menu. The color temperature and hue provide the possibility of precise control of white balance. , and this adjustment is lossless in image quality.
We select cloudy mode in the white balance to enhance the warm colors of the picture and reflect the colors of dusk.
Experience: First of all, we can recall the environment at that time, such as sunshine, cloudy sky, incandescent lamp, etc., and directly select the corresponding option under the white balance option. If the photo does not restore to the human vision at that time, fine-tuning the color temperature slider can accurately restore it.
2. Exposure correction
After completing the white balance correction, the next thing to improve is the exposure and contrast of the photo. Below the white balance command are the exposure, recovery, fill light, black, brightness, contrast and other adjustment commands.
Tips: How to judge underexposure and overexposure
At the top of the ribbon, we can see a chart that looks like many small hills. This is the histogram, which can accurately display the exposure of the photo. When a large number of peaks crowd to the far left or right and form a truncation plane, it means that the image is underexposed or overexposed, and the corresponding small triangles on both sides of the chart will be lit.
In the histogram of the sample photo, the mountain peaks have been squeezed to the far left, and the small triangle on the upper left side is lit, which indicates that there is an underexposure problem (Figure 5). So let us improve this situation. By adjusting the exposure slider, we can easily adjust the exposure of the photo. Drag the exposure slider to the right and adjust the exposure value to +0.65. The image immediately becomes brighter.
Experience: The sky tends to be over-brightened and lack detail as the exposure is increased. At this time, you can use the restore function to restore the sky details.
Drag the recovery slider to the right to the 100 position, and the detail in the sky is not lost by increasing the exposure.
Looking at the photo now, do you think the grass in the foreground is still too dark? It doesn’t matter, the fill light command is prepared for this kind of problem. Filling bright light is also called "fill light". As the name suggests, it illuminates the dark parts and restores the details of the dark parts. Move the Fill Light slider to the right to the 20 position, and the grass will become brighter than before.
Looking at the histogram, we find that there is still crowding on the left side of the histogram, and the lit small triangle tells us that some dark details are lost. At this point, it's time to use the black command. Its function is to adjust the tone of the darkest part of the image. We reduce the black value to 0, and the histogram display is finally normal (Figure 6).
The photo no longer has the problem of overexposure or underexposure, but it feels like the contrast is insufficient. It's easy, just adjust the contrast slider until you're satisfied. The corrected image already looks much better than when it started.
3. Color adjustment
Although the quality of the picture has been greatly improved by adjusting exposure, contrast, and correcting highlights and shadows, the overall color of the picture is dark and uninteresting. Let's "make-up" it.
In the color saturation correction panel, we are provided with three adjustment items: transparency, vibration, and saturation. Transparency is mainly used to adjust the transparency of the picture. The function is similar to sharpening, but the effect is more realistic. The vibration function can non-linearly adjust the color saturation of the picture. According to the different color saturation in the picture, the color saturation will be lower. The parts with higher color saturation are improved less, which effectively avoids the problem of partial color overflow.
Experience: As for the actual adjustment sequence, I think it is more reasonable to adjust the vibration first, then the transparency, and finally the saturation, so that color deviation is less likely to occur.
Adjusting the vibration to 65, the color of the picture is obviously enhanced. At the same time, with the adjustment of saturation option, we can better control the overall color of the picture. Look at the effect after the adjustment. Is it much better?
ACR also provides precise control over the independent adjustment of various tones. The sky in the picture is a bit purple? That’s okay, let’s fix it. In the tab bar, open the fourth tab from left to right - the HSL/Grayscale tab. This tab provides individual adjustment functions for the hue, saturation, and brightness of 8 colors (Figure 7).
In order to correct the color of the sky, on the Hue page, drag the blue and purple sliders to the left to make the sky bluer. After adjustment, the purple color of the sky has been improved. At the same time, we thought the sky still looked a little brighter, so we adjusted the saturation and brightness of the blue, increasing the saturation and decreasing the brightness. After adjustment, the details of the sky are richer.
Experience: Regarding the adjustment of color cast, in addition to visual inspection, the user also needs to have certain color knowledge, which requires a little extra learning.
4. Sharpen and reduce noise
So far, the image quality has improved a lot, but we still feel that the images are not sharp enough and there is obvious noise when zooming in. Let's let ACR handle it.
The third tab on the left side of ACR is the Detail tab, which contains two major sections: sharpening and noise reduction (Figure 8). Sharpening provides 4 adjustable options. The number is a parameter that controls the overall degree of sharpening. When the number is 0, the following options will have no effect. Detail is an option to adjust the sharpness of the image. The greater the detail, the more obvious the image sharpening effect. The final mask can achieve a partial sharpening effect, ensuring that image sharpening does not seriously damage details.
Experience: The radius defines the pixel range affected by sharpening. It is recommended to set a smaller radius so that the landscape photo effect will be more delicate and realistic.
Before adjusting the sharpness, please adjust the image display size to 100%, otherwise you will not be able to preview the adjustment effect. After that, we drag the sliders of the amount and detail to the right, adjust the amount to 90, detail to 50, reduce the radius to 0.5, and adjust the mask to 8. At this time, the sharpness of the image is significantly improved.
With the sharpness adjustment done, let's deal with the annoying noise that makes the sky a mess.
Noise reduction is a function designed by ACR to deal with digital noise. It provides two options, brightness is used to eliminate brightness noise, and color is used to eliminate color noise. First, drag both the brightness and color adjustment sliders to the far left to return to the state where noise is not eliminated. Then slowly drag the color slider to the right and observe the noise. Stop when the noise in the picture is no longer significantly reduced. Then adjust the brightness in the same way. The purpose of this is to avoid excessive noise reduction, causing the picture to become blurry.
There are no complex operations such as cutout and layer processing in Photoshop. The development of Raw electronic negatives is so simple and magical. Let’s create your own high-definition photo album together!