What are Raw Files? How to Open and Use Them
As you start to get more serious about photography, you may wonder what file format to shoot in. Typically you’re deciding between raw vs. JPEG. Each has their pros and cons. We’ll help you decide if a raw file is right for you, and when you may and may not want to shoot raw.
What is a Raw File?
Raw files contain the most complete, uncompressed image data, but in a form that is not directly usable and must be processed. When a digital camera captures an image, the sensor records a mosaic of digital data including the values of each individual sensor pixel. However, this data needs to be processed before it can be finalized as an actual picture.
What kind of processing needs to happen to that data? Think about all of the settings you can adjust in your camera that alters how your image looks. White balance, sharpness, contrast, saturation adjustment controls, and ISO settings are all part of this processing. None of these settings do anything to change how the light physically strikes the sensor. Instead, they change how the sensor interprets or manipulates the data that it records.
When your camera is set to record in its raw format, it saves the original, unprocessed data. It also saves a copy of the adjustments that would have been made by your camera (so that your computer can have a starting point to work from), all of your metadata, a thumbnail, and often an additional JPEG version of your file, so that you can view it on your camera.
By comparison, when you save your images as a JPEG, your camera applies all of the adjustments and saves the final image, but does not keep the original, unprocessed data.
While there are some raw formats that are more universal than others, most camera manufacturers use their own proprietary raw image format. An Adobe .dng file is the closest to a universal raw file format you’ll find. When you hear raw files being referred to as “digital negatives”, that is referring to this format, which Adobe created and made publicly available in 2003 to address the problem of the industry having no real open standard. Adobe also provides a free .dng converter and transparency about its specifications online. Here is a summary, including .dng, of some raw file formats you’ll find out in the wild:
- Adobe: .dng
- Canon: .crw, .cr2, .cr3
- Fuji: .raf
- Nikon: .nef, .nrw
- Olympus: .orf
- Panasonic: .raw, .rw2
- Sony: .arw, .srf, .sr2
What is a JPEG?
In addition to raw formats, cameras also offer the option to save your images as JPEGs. The .jpg file format was introduced in 1992 and is one of the oldest and most widely used digital image formats. In addition to their wide compatibility, JPEGs offer a 10:1 compression while maintaining image quality.
While there are certain types of image files that are better in other formats (for example, logo files with high contrast, sharp edges are best as .pngs), pictures with broad color ranges and gradients are well-suited to the JPEG format.
The most commonly used file format for digital cameras is JPEG+exif, which saves not only the image but also bundles in your exif data such as camera and lens models (useful for automatic corrections in editing software), exposure settings, time stamps of your images, copyright info (if you have set that up in camera), and more.
Benefits of Shooting in Raw
When it comes to choosing what file format to use, there are some very powerful benefits of shooting in your raw image format.
The first one is that many of the settings that influence your image are kept separate from the actual image portion of the file. This means that you change those settings during your editing process. If you find out, for example, that your white balance was completely off, you can easily change it to where it needs to be. If you’re shooting in JPEG, your ability to compensate for such mistakes will be far more limited.
While the previous section would imply that ISO is kept separate, in reality it depends. Some cameras are ISO invariant, meaning that changing your ISO when editing is identical to changing it in camera. Other cameras are not ISO invariant, so your ability to adjust your exposure is going to be somewhat reduced. How much depends on the specific camera model.
Regardless of the amount of ISO invariance your camera has, the raw file formats capture a far greater dynamic range than can be saved in a JPEG file. This allows you more opportunity to pull details out of the shadows or bring down overexposed sections by more than you would be able to with a JPEG. This is especially valuable when you are shooting in challenging light conditions. Additionally, raw files can also record more colors than a JPEG.
When you add together all of the information held by a raw file, the result is far more flexibility and freedom when it is time to edit your image. Brightness levels, color balance, sharpness, noise levels, and more can be adjusted straight from the original, unedited data. Working with a JPEG requires editing data that has already been edited in-camera, causing more limitations.
Disadvantages to Shooting in Raw
While the advantages of raw images are huge, there are some downsides that might discourage photographers from using raw.
The first is that shooting in raw requires you to do some sort of processing before your images can be used for anything. At the most basic level, this is because many programs simply won’t be able to read a raw file. You can’t upload a raw to social media, for example.
Because raw images strip a lot of the processing from your images, your initial file is going to come across as somewhat flat and dull. The sharpness, saturation, and contrast that your camera might add for a JPEG (or even for the thumbnail version) aren’t there. It’s up to you to adjust your images the way you want them.
The second disadvantage to shooting raw is that the file sizes are far larger than they are for JPEGs. Part of this is because of the additional amount of data that raw images hold, but also because the process of creating a JPEG file involves compressing that file to a degree.
Larger file sizes cause some additional challenges. When downloading them, transfer speeds are slower, especially if you are having to send the files over less than ideal internet connections, and while it’s easier to fit entire shoots on one or two memory cards, heavy shooters can still find their computer hard drives filling up quickly. When I photographed X-Games for an online blog, they specifically just wanted JPEGs for the ease of use and speed of transferring, for example. I also was able to simply grab more shots in a day using the smaller file format. While I would never shoot in anything other than raw for a portrait shoot, there are times where avoiding raw makes sense.
How to Open a Raw File
As mentioned above, many programs are not compatible with raw image file formats. If you are shooting in raw, you need to have a workflow that allows you to easily open and convert the raw file to another format more suitable for whatever its intended use is (publication online, print, etc).
Adobe products are the most popular.
- Lightroom opens the raw files natively, making for an easy and streamlined system to load, edit (including in bulk), and export your images.
- Photoshop is a little more complex, requiring the use of Adobe Camera Raw to prepare the file for editing.
Other photo editing software can also easily handle raw files include Capture One, DxO PhotoLab, Affinity Photo, darktable, and more. You can also download Adobe’s DNG converter for free here.
Should You Shoot in Raw or JPEG?
Whether you shoot in raw or JPEG comes down to your approach to photography.
Perhaps the biggest consideration is how much you want to edit your pictures. If you are completely content just snapping the shutter and being done with it, sticking to JPEGs is probably the right decision. And the reality is that a lot of cameras have fairly robust settings that can let you tweak the final image in-body. If you are careful with those settings and sensitive to the light conditions and exposure settings, you can get great images that you won’t have to touch later.
It’s also worth noting that a lot of cameras let you shoot both at once. If you have the space for it, you can work directly with your JPEGs now and your raws later when you’re more comfortable with editing. Check out Why You Should Re-Edit Your Old Photos for more about why you should save your old raws for later use. I like to have JPEGs on-hand for browsing, but then have the raws also for when it’s time to actually edit.
If you already know you want to do more editing, raw is the way to go. The amount of flexibility in your processing of a raw image is far superior to what you can do with JPEGs, and in some cases you can even rescue images that would have been ruined and unusable had they been shot in JPEG. If you find yourself only occasionally making edits, programs like Adobe Lightroom make it very easy to batch process photos, adding the same adjustments to all your images at once. This takes away most of the work while also giving you the flexibility to focus extra attention only on specific images that you feel could benefit from it.
Raw file formats are what most photographers are using exclusively these days. However, there are certainly valid reasons not to shoot in raw. It can be intimidating if you’re just starting out and aren’t yet comfortable with editing your images. Even pros will sometimes make very conscious decisions to not shoot in raw. Consider the pros and cons, and ultimately what will work best for your end goal.