Your camera sees more than it shows. In order to share with you a digital copy of the image, it encodes the information received on the matrix into a certain format. If this is JPEG — the ubiquitous image formatting standard — then some information is lost: the camera automatically converts photos in a reasonable time and with available resources (the electronic “brains” of your camera are obviously inferior to the “stuffing” of a desktop computer).
As a result, the memory card saves not what got on the matrix, but how the camera processed it. It turns out a finished dish with its own advantages, but devoid of flexibility.
If you want to experiment with the “ingredients”, you need to take a step back and set up the camera so that instead of a formatted shot, it gives you the most complete reflection of what was captured by the matrix. This is how photos are obtained in RAW format, about the pros, cons and principles of working with which we will talk in this article.
How a “raw” photo works
Benefits of RAW
The transformation of a RAW file to JPEG takes place in several stages, each of which affects the image in its own way. First comes the demolition. In order to understand how this process works, let’s first understand how digital cameras generally acquire images.
The camera matrix consists of millions of pixel cells. When you press the camera’s shutter button, each of these cells begins to absorb light. Then the light in each cell is counted. To make images in color, a filter (usually three of them: red, blue and green) is superimposed on top of each light collector, allowing only a certain color to pass through.
The most common matrix color filter of this kind is the Bayer matrix, which consists of alternating rows of red-green and green-blue filters.
Dematrization is to interpolate (i.e. find the missing values) of the color components with the original image passed through the Bayer matrix so that each cell is represented not by one color number, but by three that make up the usual color representation format, for example, RGB.
This is a resource-intensive process, so the camera inevitably goes for simplifications during RAW to JPEG conversions. If you save the image in RAW, you can do the dematrization on your computer yourself.
Another feature of RAW is that it retains the original bit depth of the image. If you remove the original data in JPEG format from the matrix, you get 8 bits per color channel. Accordingly, the dynamic range (chiaroscuro interval between absolutely black and absolutely white) of the frame will be limited to 28=256 shades of red, blue and green in the RGB model.
In RAW, the bit depth is higher — 10, 12, 14 or 16 bits per channel. These bits of RAW files have additional data that will allow you to expand the dynamic range and get out of it those details that are lost in JPEG.
RAW uses lossless compression, unlike JPEG compression, which produces compression artifacts. RAW files contain more information and are more compressible.
RAW processing does not make any changes to the original file. All settings are saved separately, so the source cannot be corrupted. To get an edited image, the RAW file must be converted into a finished image with the selected settings.
Disadvantages of RAW
The shortcomings of RAW are in the volume and speed of recording. If you shoot strictly in RAW, the memory card will fill up faster, and the number of frames per second will decrease compared to JPEG.
In addition, RAW does not have a single encoding standard, each manufacturer defines it separately, they also create their own software (called RAW converters) for processing images in this format. For users, this means that the software can choose depending on which manufacturer’s camera they have.
For example, Nikon cameras encode RAW in NEF/NRW format, and the converter that comes with the camera for free can only work with files in this format. There are also universal programs that support most RAW encodings. Let’s consider each of these types separately.
Programs for working with RAW
Supplied with the camera on a CD. You can also download the latest version from the Nikon website. Supports Windows and MacOS.
The program allows you to quickly adjust the white balance: just use the eyedropper tool to specify a place in the photo that will be taken as a reference point when adjusting the white balance. It can also be adjusted manually using the “color temperature” and “shift” sliders.
There is a horizon alignment function, for this you need to draw a line along which the photo will be aligned. By adjusting the exposure, you can adjust the brightness of the picture. The Highlights Protection and Shadows Protection sliders bring out details in the highlights and shadows of the frame.
Horizon alignment in Capture NX‑D. Source: prophotos.ru
The “noise reduction” function eliminates digital noise that occurs if the picture was taken at a high ISO value or when the brightness was raised too much during processing. Noise reduction has two sliders: “Intensity” and “Sharpness”. If you twist the first one too much, you run the risk of losing small details in the picture, you can try to restore them using the second slider.
Processing ends with exporting the image to JPEG or TIFF (it weighs more than JPEG, because it saves the image without loss in compression).
Digital Photo Professional
Software for owners of Canon cameras. To download, you need to specify the serial number of the camera on the Canon website. Supports Windows, Linux and Mac.
Rough adjustment of brightness, white balance can be done by thumbnail, and then convert, for example, a batch of photos into JPEG using the batch processing function.
More fine-tuning, in addition to the functions listed in Capture NX-D4, allows you to adjust the color interpolation.
Imagine Edge Desktop
RAW converter for Sony cameras, there are versions for Windows and MacOS. It is notable for the presence of the function of remote control of the camera when connected via Wi-Fi or USB.
Raw File Converter EX 3.0
Fujifilm’s camera software runs on MacOS and Windows and is generally on par with other free converters.
Cross-platform (Windows, Linux and MacOS) and free converter, but quite slow. There are so many functions in it that their analysis is enough for a separate article.
The processing process in this software begins with the already mentioned dematrization procedure. Raw Therapee offers different dematrization algorithms for the user’s choice. There are a lot of algorithms — some work out the details well, others show the right color better. There is no best algorithm, each one is suitable for its own situation, so the scope for experimentation is immense.
Next, the program offers the usual steps for a RAW converter: exposure and image geometry correction, white balance and color balance corrections, noise removal, sharpness correction.
Raw Photo Processor
A free converter that works exclusively on MacOS.
The program contains film profiles, captivates with a simple interface and good picture quality.
Paid converter available on Windows and MacOS. A monthly subscription costs about $28.
The converter is distinguished by the support of ICC camera profiles (i.e. color profiles — data on how the same color looks on different cameras) and a highly customizable interface. Capture One has a whole arsenal for working with color, and working with layers in it is implemented exactly like in Photoshop. If you mask one or another object in the frame, you can process it separately from the rest of the photo.
Adobe Camera Raw
Tiny plugin for Adobe Photoshop.
By default, it offers automatic settings for the main exposure parameters, and if it detects overexposed areas in the frame, it reports about it. If during processing you violated the exposure yourself, the plugin will also warn you about this. It does not have batch processing tools, but Photoshop itself will help with this.
Details on how to use the plugin can be found here.
Adobe Photoshop Lightroom
Separate paid software from Adobe. It has few differences from Camera Raw, the main thing is the presence of cataloging and support for its own plugins.
RAW is not a universal replacement for all other image encoding formats. But it’s a useful tool that will open up new creative possibilities and ways to correct mistakes while shooting.
The main pros and cons to remember about RAW:
- RAW is the original data taken directly from the camera’s matrix. The advantage of the format is that no corrections are applied to the image, and all further processing is given to the user. This is not the case with JPEGs.
— The main disadvantages of RAW: file size, shooting speed and lack of coding unification.