DNG, JPEG, TIFF, PSD, PSB, and more: photographers have more options than ever for saving their files, but not every option is a good choice. Do you know the benefits of each file type and when you should use them?
One of the best ways to think about file formats is milestones in the workflow. From choice of file format in camera, to how you store your images on the computer, to how you pass them between editing tools, to how you archive, export and share, each step may have a different format associated with it. As a result, this guide will follow a roughly linear workflow. If a step isn’t relevant to you, you should still consider whether that format is something that could be useful in your process.
The choice of file format at time of capture is going to be limited by your choice of camera. Typically, any camera beyond the most basic point and shoots will support some sort of raw format. The name will vary based on the vendor: Canon’s .cr2, Nikon’s .nef, Sony’s .arw, and Fujifilm’s .raf all refer to the same type of file. These file types have the least amount of processing, particularly compared to a JPEG, but will also be larger and require more work to be usable.
Raw files are processed through a raw processor, like Lightroom, Capture One, or the manufacturer’s provided software. This processing step lets the photographer make changes like adjusting the brightness and color balance, often with greater latitude than a JPEG.
A few downsides to raw files include the larger file size and drastically reduced interoperability with devices and services: you can’t upload a raw file to Instagram, for instance. Over the last few years, operating system support has gotten better, with support for thumbnails, viewing, or even basic editing now being built in.
Raw files can support some amount of compression, with many cameras offering a choice between lossless, lossy, and uncompressed raw files. Typically, there is no reason to go with uncompressed over lossless compression, excluding specialty cases. When it comes to lossy compression, most cameras I’ve seen haven’t made lossy raw files significantly smaller enough to merit the decreased quality (if I need the space, I’ll just shoot JPEG). As a result, lossless compression is my go-to choice on cameras.
JPEG files, at the time of capture, lock the photographer into a number of choices. Prominently among these are white balance, quality, and any camera color-processing steps. While JPEG files can still be opened in Photoshop and edited after the fact, many pieces of information are thrown away to reduce size. This discarded information reduces the latitude possible in editing; for example, brightening the shadows will begin to show artifacts more quickly than a raw file.
Typically, a camera allows the selection of different degrees of JPEG compression. For example, choosing fine over basic means the resulting file will be slightly larger (although still much smaller than a similar raw file), but have fewer compression artifacts.
The tradeoffs inherent to shooting JPEG relegate it to one of two use cases, at least in my experience. For me, these are scenarios like shooting insignificant images, like eBay listing photos, where I just need a quick shot, and high-volume shoots, like a photobooth at a wedding. While the simplicity can be a great benefit for some photographers, storage is cheap (see 256 GB SD cards for less than $80) and post-processing so significant to the final look of an image, I’m almost always using raw.
Also worth including in this category are .dng files. Digital negative, or a DNG file, is Adobe’s publicly available archival format. While this file is more relevant in the archival section, there are a number of camera manufacturers, like Leica, as well as mobile device manufacturers, like Apple, that support shooting and saving DNG files. For shooting DNG, many of the same tradeoffs between raw and JPEG apply to DNG versus JPEG.
The easiest way to sum up capture formats is the decision between speed and size. Shooting a JPEG takes less space on a memory card and can reduce workflow steps required from capture to export, but at the cost of quality, editing opportunities, and post-shoot fixes. Raw files are larger, slower to move around, and require post-processing, but do the best job of preserving quality and providing editing options. One last advantage to raw files is the ability to go back and edit them with more advanced tools: for example, Adobe’s more advanced debayering via “Enhance Details” can drastically improve the rendering of Fujifilm’s raw files.
There’s a lot of baggage that goes along with the choice of what format to shoot. The question of what format to use for storage is a lot simpler. For me, there’s no reason to convert from the raw format I shot in. I store my images in their original raw format and use Lightroom to view and non-destructively edit them. If you're running low on storage, consider adding some drives to your computer or purchasing a DAS or NAS product, like Synology's DS1819+, which supports eight additional HDDs.
If you’ve shot JPEG, you may want to consider going to an intermediate format for storage of select files. Saving a JPEG with changes is a destructive process, as the algorithm will continue to strip away information to achieve smaller file sizes. For a photographer, this means that opening a JPEG, making a change, and saving it, then repeating this process another few times will result in a final image of meaningfully lower quality.
As a result, it might make sense to convert a select number of JPEGs to a format like DNG or TIFF, as this can prevent accidentally saving over the original JPEG and diminishing the quality. Typically, you’ll need to save a final version of this image back to JPEG for best interoperability with non-photographers, apps, and websites.
Storage of raw files as DNG carries a number of hypothetical benefits, which Adobe’s website details in more depth here, but essentially, it boils down to the format being open, ensuring greater support in software in the future. This feels like a bit of a future problem, especially if you shoot a major brand of camera (Canon’s raw format, for instance, isn’t about to disappear), but may be worth considering for use in backups, or special images like family and historically significant images.
Shooting and Storing
The choice of format at the time of capture directly influences everything that comes after it, since you can’t recreate information that was lost along the way. Choosing to shoot with raw does carry trade-offs, but for most types of photography, they are well worth it. While the choice of storage format mostly follows the choice of capture format, editing presents a whole host of different considerations.