The RAW format is equivalent to digital negatives. It is very popular among photography enthusiasts because it can save the content during shooting without compression and distortion. Vignetting is the dark corners around the photo. Vignetting in photos has no value other than creating a LOMO effect. Different from processing the vignetting effect in ordinary pictures, not all versions of Photoshop can process RAW format files, so how should we process such photos? In this issue, we invited someone with many years of experience in photography and processing RAW format photos. Hao Fei, come and tell us how to process RAW format photos in post-production.
Why do photography enthusiasts like to use RAW format and what are its advantages?
Simply put, the adjustment of the uncompressed source file mode in the RAW format can achieve distortion-free adjustment, which means that the details of the image will not be lost during the adjustment process. This is why photography enthusiasts like this format. Relatively speaking, the adjustment process of ordinary format photos is difficult to avoid losing image details. In addition, RAW can better correct the moiré pattern and dispersion defects of digital cameras in images.
Under what circumstances can RAW format be obtained?
In the past, some professional or quasi-professional digital cameras included the function of shooting in RAW format. With the popularity of DC, a large number of consumer-grade digital cameras now also have this function. When needed, just select the RAW item in the camera's image quality menu.
How to remove vignetting from RAW photos
What software is needed to process photos in RAW format? When you install Photoshop CS3 in default mode, a RAW processing plug-in called "Camera RAW" will be installed at the same time. After installing this plug-in, the icons of all RAW format files will change accordingly. However, the suffix name of RAW files varies according to different camera manufacturers. For example, Canon's is CR2, Nikon's is NEF, and Fuji is RAF, etc. However, this does not affect their post-processing. All operations are the same. . Just double-click the RAW file we need to modify in the folder to directly enter the "Camera RAW" processing interface.
Camera RAW download: http://www.mydown.com/soft/multimedia/browsing/404/424904.shtml
Reference article "Adobe releases the latest version of Camera RAW 4.2 plug-in"
The photo in Figure 1 has obvious vignetting and is underexposed. We adjusted the brightness of the entire image by debugging "exposure" and restored and corrected the details that were too dark due to underexposure. Use "Fill Light" to adjust the details and balance of the grayscale parts, and then use "Restore" to correct some locally lost details. Change "Brightness" and "Contrast" to restore and correct picture exposure. Then enter the lens correction menu (Figure 2) to fine-tune the lens vignetting. In fact, this is to adjust the dark corners of the photo. During the adjustment process, pay attention to the light and dark relationship of the entire image, and control the adjustment of the vignetting according to the exposure scene. If you overcompensate, the dark corners will become "bright corners." Then use the "midpoint" to adjust the range of vignetting effects, so that the four corners feel consistent with the overall light and dark. Finally, with appropriate sharpening, a RAW format image file will achieve the effect we expected.
Tips: To output a beautiful photo, the quality of the original image must reach a certain level of accuracy, so during the RAW adjustment process, you must pay attention to the difference in image resolution (dpi) between photo output and computer screen display. The image we see on the monitor only requires 72dpi, while 240dpi or 300dpi is required when developing or printing out. But it’s not that the higher the resolution, the better. It also depends on the performance indicators of the output device itself. Generally speaking, if the output effect of using 300dpi printing resolution is not good, you might as well reduce the printing resolution to 200dpi. Usually, after such a setting, you can print photos with better effects.
Finally, click "Open Image" and save it again in Photoshop to complete the modification of the vignetting of the RAW format photo.
Experts’ tips: Common problems encountered in RAW post-processing
Some lenses have two prominent problems in daily use: First, there are obvious red and purple edges on the transition line between light and dark color blocks, usually called "purple fringing"; second, the front end of the lens is equipped with The filter will intensify the vignetting. Especially when using gradient gray, polarizer, etc. at the wide-angle end of the lens, the vignetting becomes particularly prominent. Enter the lens correction menu, carefully adjust the "amount" of the lens vignetting to restore the darkening tone of the four corners, and then use the "midpoint" to adjust the range of vignetting until the darkening of the four corners of the photo is completely improved by visual inspection. . This processing is also very necessary for preparing wide-angle lens photos for splicing.