It has long been a trend for mobile phones to rely on computational photography. The purpose is to use algorithms to make up for the shortcomings of the hardware. However, it can be found that in addition to better algorithms, flagship mobile phones also have built-in RAW format. This has also made many players wonder. Since the mobile phone can automatically calculate high dynamic range photos, what is the meaning of shooting RAW? Where? And what else can be used?
What is RAW format?
Just like common image files such as JPEG, GIF, PNG, etc., RAW is also one of many image formats, but its biggest difference from the aforementioned image files is that RAW completely records what the camera’s sensor captures when shooting. All original information, including exposure value, color, white balance…etc. Because of this, compared to the familiar JPEG, RAW not only has the most image details and the best image quality, but also has greater post-production space and flexibility. Therefore, most experienced or advanced photography players generally know how to use it. Choose to shoot RAW and then perform post-production so that the work can be presented more in line with your expectations. Compared with RAW, JPEG, whether it is generated by default after shooting with a mobile phone or camera, is actually a file that has been processed by an image processor or chip. The advantage is that the format is universal and the file is smaller, regardless of the platform. Both can be displayed directly and are easy to share. The disadvantage is that the files are compressed and stored destructively, so the image quality is usually reduced, and the post-production space is much smaller than RAW. This will be explained in detail later. .
What is the difference between RAW and JPEG?
Although RAW has the advantages mentioned above, it also has corresponding disadvantages. For example, compared with JPEG, RAW files are significantly larger. Generally speaking, a RAW is about 5 to 10 times larger than a JPEG, which is less friendly to storage space. It also requires specific apps or software (such as Adobe Lightroom, etc.) to open, post-produce and convert it to a JPEG. In other words, RAW cannot be directly published to online communities such as Facebook and Instagram because these platforms do not support the RAW format. They must be converted to JPEG through the above-mentioned App or software before they can be published and shared smoothly. If you really want to make an analogy, you might as well think of RAW as a kind of “digital film.” Just like when our parents took photos for us when we were traveling when we were young, we always had to send rolls of black film to the photo studio for printing at the end of each trip. , the next day we can get photos that we can understand. RAW is the negative, and the photo studio is Adobe Lightroom or Photoshop and other software that can open RAW. The action of printing can be regarded as post-production, and the final photo we get is JPEG.
▲ Smartphones with high product positioning have built-in RAW format functions, giving players one more choice when shooting.
▲ The biggest advantage of the RAW format is that it can withstand extensive post-production. Even photos that fail to be taken have a high chance of being salvaged.
Post-production differences between RAW and JPEG
As mentioned more than once before, the RAW format has a larger post-production space because it completely records all the original information captured by the photosensitive element. But what is the difference in the adjustment space between RAW and JPEG in post-production? Can it be quantified so that we can understand it more clearly? For flagship mobile phones on the market today, the amount of color information that can be recorded in the RAW format is about 10 to 14 bits. Assuming that the mobile phone can shoot 14-bit RAW, it means that there are about 16,384 levels (2 of 2) from full dark to full bright. 14th power), the color combination is 4,398,046,511,104 (4 trillion 39.8 million colors, RGB each 14bit, so it is 2 to the 42nd power); even if your mobile phone “can only” shoot 10bit RAW, there are 1,073,741,824 (1.07374 billion Color, RGB each has 10 bits, so it is 2 to the 30th power); as for JPEG, it can only record 8 bits of information, there are only 256 levels from full dark to full light, and there are only 16,777,216 color combinations (16.77 million colors, RGB each has 8 bits, so is 2 to the 24th power).
This explains why RAW has a much larger post-production space than JPEG. After all, unlike JPEG, which performs destructive compression during storage, RAW faithfully retains every image recorded by the sensor. information data, there is also a greater opportunity to restore the image to be as real as seeing it with your own eyes through post-production. However, for many beginners, they are not used to the effects presented by apps such as Adobe Lightroom after reading RAW at first. The image looks quite bland, which is commonly known as “returning to the original shape”. They think it is very different from JPEG. Don’t know where to start post-production. In fact, it is because these apps do not read the control files of various brands of mobile phones after loading RAW, so what you see is the original appearance of the image. Therefore, some players will shoot JPEGs and then use Adobe Lightroom and other apps for post-production. If you do the same, it is recommended to change this habit immediately! As mentioned before, JPEG can only record 8-bit data. Compared with RAW’s 10-14 bit, it is not difficult to see that the bit depth of JPEG is much smaller than RAW. Not only is it easy to be stretched in post-production, but it is also prone to color gradation breaks. Therefore, if you want to have more flexibility in post-production of your images, remember to shoot in RAW format.
▲ Since the bit depth that JPEG can record is much smaller than RAW, it is easy for the color levels to be broken in post-production.
What is the difference between Apple ProRAW and regular RAW?
Players who are using the iPhone Pro series should know that Apple’s RAW is called “Apple ProRAW”, and how is it different from ordinary RAW? In fact, Apple ProRAW combines the standard RAW format with the image processing functions of the iPhone, which means that in addition to completely recording all the original information of the sensor, it also combines the “deep fusion” and “smart HDR” of its own computational photography. Therefore, It will have more advantages in post-production editing. Apple ProRAW files are much larger than JPEG/HEIF files. The file size of an Apple ProRAW file is about 25MB on 12-megapixel models such as the iPhone 12 Pro and iPhone 13 Pro series, which is the size of JPEG/HEIF files. 9 to 12 times. If used on 48-megapixel models such as the iPhone 14 Pro and iPhone 15 Pro series, it will be even larger, about 75MB, which is 3 times that of the previous model Apple ProRAW. Therefore, it is recommended to use it when facing extreme If the lighting environment or it is confirmed that there will be significant post-production adjustments, then enable Apple ProRAW format shooting to save storage space.
▲ After loading the Apple ProRAW file into Lightroom, you will find that the Apple ProRAW profile has been pre-applied.
As for the actual difference, we can understand it by reading Apple ProRAW through Adobe Lightroom. After loading the Apple ProRAW file of the iPhone 15 Pro series into Lightroom, you can find that the profile panel in the editing panel has pre-read the Apple ProRAW profile, and then focus on the details you want to adjust, such as Make appropriate fine-tuning of white balance, exposure, contrast, highlights, shadows, white, black, texture, sharpness, dehazing, vividness, saturation, etc., and then decide whether to adjust the tone curve, HSL/ Color, color grading, details, lens correction, distortion, effects… and other panels can be used to adjust other items. Here we can see the difference between Apple ProRAW and general RAW files. Figure 1 below is Apple ProRAW that applies the “Adobe Standard” description file, which is used to simulate general RAW; Figure 2 below is the original Apple ProRAW format. It can be clearly seen from these two pictures that although both are RAW formats, because Apple ProRAW combines the relationship between “deep fusion” and “intelligent HDR”, the dynamic range and color presented are better than those of ordinary RAW. It’s even more pleasing to the eye. With a little post-production, the image can be made to match your expectations. It’s easier to edit to the ideal state than ordinary RAW.
▲ Apple ProRAW combines standard RAW with the iPhone’s computational photography, making it easier to edit to the ideal state.
Is it necessary to shoot RAW when mobile phones already have computational photography?
Although the benefits of shooting RAW are obvious, for ordinary players, when they see that they need to use Adobe’s App to post-produce RAW, most people may give up at first. After all, for many people, Lightroom is a professional post-production software. App, not to mention that mobile phones can already take good photos, so is it necessary to take RAW photos? Due to the hardware limitations of mobile phones, the size of the photosensitive element currently equipped is actually not large compared to that of the camera. Therefore, the range of adjustment of its RAW format is naturally not comparable to that of the camera. However, in recent years, with the number of mobile phones equipped with 1-inch photosensitive elements, With the advent of the camera, I believe that the distance between you and the camera will be shortened in the future. However, at this stage, when shooting memorable or important scenes, it is recommended to switch to the RAW format at the right time. After all, as mentioned above, the amount of information that can be recorded in the RAW format of today’s mobile phones is at least 10 bits, and it also retains In order to capture all the information recorded by the current sensor, it has far more flexibility to adjust exposure, white balance and color in post-processing than JPEG. Of course, for general daily shooting other than the above, it is still recommended to use JPEG / HIEF format. In addition to saving storage space on the phone itself or on the cloud, the most important thing is that the direct-out images after calculation by mobile phones are actually pretty good. The imaging effect is more than enough for general life recording or social sharing.
▲Although mobile phone computational photography can already achieve good results, it is easier to produce pleasing images by shooting RAW at the right time in environments with high contrast.
As for shooting in RAW format with a mobile phone, if you want a better presentation of the image, it is usually recommended to use the Adobe Lightroom app for editing. Although the app can use most basic functions for free, such as adjusting exposure, white balance, contrast, sharpness, cropping, etc., if you want to edit RAW format, you still need to pay to subscribe to advanced functions. In addition to supporting RAW format editing, Lightroom’s advanced functions also include AI-powered healing brushes, masks, powerful geometric tools, batch editing, and additional Adobe cloud storage space, which can be used on mobile phones. The captured RAW format can be accessed across devices for post-production, which is very convenient and not expensive (NT$326/month). Subscription is recommended for players who are keen on mobile photography.
Lightroom editing RAW application
Although Adobe Lightroom is a professional image editing app, its interface is very simple and easy to use. Especially after Lightroom was recently updated to version 9.0.1, the toolbar has been simplified, providing simpler and more intuitive operations. experience. Generally speaking, after reading RAW into Lightroom, preliminary adjustments will be made to the image through the “Edit” panel, including exposure, white balance, color, sharpening, etc., so that the image has a preliminary outline, and then through Panels such as “Mask”, “Repair”, “Crop” and even “Preset Set” can be used for further post-production adjustments to achieve the most perfect presentation of the image. The following uses Apple ProRAW shot with iPhone 15 Pro to demonstrate the application of Lightroom editing.
Step 1: Adjust the exposure, highlights, shadows, vividness and saturation in the “Edit” panel; the color temperature of the original image is warmer, so it is significantly reduced to 3250K.
Step 2: The sky looks dull. Use the gradient mask to enhance the sky. The main purpose is to increase the color temperature and saturation to make the sky more three-dimensional.
Step 3: Use the gradient mask on the ground to enhance the warm color illuminated by the tungsten lamp, adjust the color temperature and hue toward yellow and purple, and add a little saturation.
Step 4: If you want the color temperature of the sky after sunset to look more dreamy, you can go to “Color Mixing” in the “Edit” panel and adjust the blue hue.
Step 5: Through the comparison before/after editing, I believe you can clearly see the difference.
This article was simultaneously published in PC home Magazine
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