The topic of RAW vs JPEG image format is one of the never-ending debates in photography. Some photographers say shoot in RAW, while others say shoot in JPEG. What is the RAW format in digital photography and what are its advantages and disadvantages when compared to JPEG? Having a thorough understanding of file formats and their differences is essential for photographers in order to make the right choices when going through camera settings.
I remember my first time going through my camera options and reading the manual, wondering about what RAW does and why I should consider using it. JPEG is a no-brainer – it’s the default image format that is used in most smartphones and point-and-shoot cameras, so we know what to expect from it. But when I came across the RAW image format, I wanted to find out how it affects images immediately, as the word “raw” by itself sounded intriguing to me. So I went ahead and changed my camera settings to RAW and tried to take a picture. The first thing I noticed, was how small all of a sudden my memory card became. “Wait a second, how come the number of pictures went down from several thousand to less than 500?” is what went through my head. The image looked exactly the same on the LCD and yet it consumed more than three times more storage. Bummer.
Then, I took the memory card and inserted it into my laptop. To my surprise, I couldn’t even see or open the darn thing! “Worthless”, I exclaimed, then changed my camera settings back to JPEG.
Sounds familiar? If you are in a similar situation, do not make the mistake of abandoning RAW as I once did and read on. You truly need to understand all the advantages and disadvantages of both formats before making this important decision, because you might be sorry that you didn’t later.
1. What is a RAW Image?
A RAW image (also known as a “digital negative”) is an image file that contains unprocessed or minimally processed data from a digital camera’s sensor. Similar to raw food ingredients that need to be prepared and cooked before consumption, a RAW image also needs to be post-processed in software before it is ready to be printed, shared or shown on a display device. Unlike JPEG files that can be easily opened, viewed and printed by most image-viewing / editing programs, RAW is a proprietary format that is tied to a specific camera model. Therefore, in order for the software to be able to work with a RAW file, it must be compatible with the particular camera the RAW image was captured with. Post-processing RAW images can yield greater dynamic range (with better highlight and shadow recovery options), superior colors and in some cases can even provide more detail when compared to JPEG images.
RAW files typically consist of three main parts: the actual RAW data from the image sensor, a camera-processed full-size JPEG preview + thumbnail, and all relevant header and metadata information. For cameras to be able to display the recorded image on the rear LCD or on the electronic viewfinder, the camera-processed JPEG preview is used. The image header, as well as parts of the metadata are used for interpreting sensor image data by RAW conversion software, while other metadata information such as exposure settings, camera and lens model, date/time, etc. can be used for filtering, sorting and cataloging images.
1.1. Advantages of RAW Format
Far more shades of color. Compared to an 8-bit JPEG image that can only contain up to 16.8 million colors (256 tonal values for Red, Green and Blue channels), a 12-bit RAW image can contain up to 68.7 billion colors (4,096 tonal values per color channel). Stepping up to 14-bit RAW images increases RGB tonal values significantly to 16,384, which boosts the potential to 4.4 trillion colors. And some high-end cameras are even capable of recording 16-bit RAW images, which results in 65,536 tonal values per color channel, resulting in mind-boggling 281 trillion colors. If you are wondering about the difference between this number vs JPEG, that’s 16.8 million times larger!
Wider dynamic range and color gamut. A RAW image contains wider dynamic range and color gamut compared to a JPEG image. For highlight and shadow recovery when an image or parts of an image are underexposed or overexposed, a RAW image provides far better recovery potential compared to JPEG.
Finer control and adjustment potential. When a RAW image is generated, all camera settings, including camera-specific and manufacturer-specific information (also known as image metadata), are added into the file, along with the RAW data from the image sensor. The metadata is then used for demosaicing and RAW conversion process, which is what converts an otherwise black and white RAW image to color and applies particular gamma correction, white balance, brightness, contrast, and other adjustments. This means that the RAW image itself remains unmodified or “non-destructive” – you can make changes to the image later in post-processing applications like Lightroom and Photoshop.
Can adjust color space after image capture. Similar to white balance, color space (such as sRGB or Adobe RGB) is not saved into RAW images either, which means that you can change it to any color space later on.
RAW images are lossless. Unlike JPEG, RAW images typically utilize lossless compression (unless specific “lossy” RAW compression is selected), meaning they do not suffer from image-compression artifacts.
Better sharpening potential. No image-sharpening is performed on RAW images, which means that you can use better and more complex sharpening algorithms for your photos.
Can be used to convert to other RAW formats. When using RAW image format, images can be merged together to create HDR or panoramic images in DNG file format when using Adobe Photoshop Lightroom. This opens up opportunities to edit images just like RAW files, with maximum editing potential and recovery options.
Proof of ownership and authenticity. Unlike JPEG images that can be easily manipulated, RAW images can be used as evidence of your ownership and authenticity of the photograph. If you saw an alien and have a RAW image to prove it, nobody would be able to argue that you manipulated the image in Photoshop :)
1.2. Disadvantages of RAW format