RAW Image Format

When you press the shutter, light passes through the lens and hits the sensor. The JPG files we usually use are "finished meals." The camera has already cooked that light into a fitting color and brightness on its own. It is easy to look at because it is already seasoned, but if it turns out too salty or too bland, it is hard to get back to the original taste.

A RAW file, on the other hand, is raw, unprocessed ingredients. The pure light signal sensed by each pixel of the image sensor is stored neatly, with no seasoning added. Just as a chef adds more salt or adjusts the heat to taste, the photographer can shape the mood of the photo as they like.

For example, a face that came out dark because of backlight can be rescued from a RAW file with far less breakup and no color distortion compared with a JPG. That is because the light information hiding in the dark shadows is not thrown away. It stays intact inside the file.

The biggest reason is the amount of information used to describe color and brightness. A typical JPG file expresses color in 256 levels (8-bit). A RAW file usually records 4,096 levels (12-bit) or 16,384 levels (14-bit), and some medium-format cameras go as far as 65,536 levels (16-bit). That makes the gradation of color and light and dark much smoother and richer.

It really shines when you adjust white balance, which matches the color temperature of the light. An indoor photo that came out yellowish under an orange incandescent bulb can be fixed to look like it was shot outdoors in daylight by moving just one slider. This works because the data is pure, from before the camera's internal color processing, so the quality does not break down.

You can also bring back much of the detail in clouds that were blown out white by too much exposure. Because a wide range of light is preserved, RAW helps you avoid fatal failures even in rough shooting conditions.

So should you shoot every everyday photo in RAW? Not necessarily. Because it keeps all the information instead of throwing any away, the files are very large. Even on the same memory card, you can store about a third to a quarter as many photos as with JPG, or fewer.

Also, a RAW file is not a finished picture file. Unless you convert it with a dedicated editing program, you cannot send it to a friend in a messaging app or post it straight to social media. The camera only wrote down the sensor's raw numbers, so to show it on a screen, a computer has to interpret them and render an image.

In the end, if your goal is quick sharing and easy storage, a light JPG that opens anywhere is much more convenient. On the other hand, in moments that call for careful editing, such as an important ad shoot or a landscape photo, RAW does its job well.