A DNG file is a fairly common high-quality image format, although it is a relative newcomer to some file types such as TIFF, which is decades old (2004 vs. 1986, respectively).
Many applications and most operating systems support DNG files, and some camera manufacturers allow you to save photos in DNG format directly from the camera. Otherwise, it is relatively easy to convert photos to this format afterwards. For anyone unfamiliar with this format, these questions remain: What is a DNG file, and how do I open it?
What is a DNG file?
DNG is the short name for a digital negative, an image format created by Adobe in 2004. It is called a RAW image, although in many cases it is not captured directly by the camera, which means it is not the native image. RAW format for most cameras. Canon uses CR3 and Nikon has NEF, and each of these formats perfectly represents the data captured by their cameras. While many manufacturers have proprietary formats, there are several that record in DNG.
Something common to all RAW image files, including the DNG format, is much higher image fidelity than files saved in JPEG or HEIC format. These types of compressed images are specially designed to save storage space while accommodating a bit of image degradation. The main purpose of DNG is to store a high quality file that matches the original image taken by the camera. The difference between DNG and JPEG or HEIC is not always noticeable when looking at the stored image, but often becomes apparent after applying edits or zooming in to see the finer details.
How to open a DNG file
Most operating systems support DNG files, displaying thumbnails in the file browser and being able to open them for viewing using the built-in photo application. For example, a Mac computer can display thumbnails and display large Quick Look previews by simply pressing the spacebar while using the Finder. The return key can open in the Preview app or in a third-party photo editing app that supports DNG.
The experience is similar on Windows, showing thumbnails in File Explorer and opening with the Photos app, unless an editing app is installed on the PC, such as Adobe Lightroom, Capture One, DxO Photolab, ON1 Photo RAW or other RAW editors.
Several photo editing and painting apps can open and edit DNG files even if they don’t specialize in RAW editing. Almost any Adobe application can open DNG, and many more support DNG like any other image type, including favorites like Corel Paint, Affinity Photo, Paint Shop Pro, and Pixelmator. Chances are that an application installed on most computers can open and edit DNG files.
Who created the DNG format and why?
Adobe created the DNG format in 2004 to provide a universal RAW format, simplifying software support for a large number of cameras. Recognizing the need for a standard, Adobe developed DNG as a publicly available RAW archive format for photographs. Adobe owns the patent on this format but allows free use as long as there is attribution given to Adobe in the source and documentation. This makes it an attractive solution for organizations and government offices that prefer to use industry standards.
The easy availability of DNG has been a strong incentive to develop software and hardware support for newcomers. Smartphone makers like Google, Apple, and Samsung started supporting RAW images around 2014, with all three opting to use the quick and easy option of saving to DNG. At first, a third-party app was needed to capture, view, and edit DNG files, but now this is possible using the apps built into Android and iOS.
Is DNG a lossless photo format?
DNG is generally considered a lossless format, but there is an option to use compression to drastically reduce the file to about a third of its normal size. The algorithm is based on JPEG compression but with some critical tweaks to improve the result compared to creating a similar sized JPEG file.
While most photographers still prefer to save their best work in lossless DNG format or keep the original, it’s nice to have a more efficient alternative. With such a reduction in file sizes, every raw file can be stored in DNG format without breaking the bank, buying more and more discs, or paying a big monthly bill for a cloud storage subscription.
Are there any downsides to using DNG?
There may be cases where it is not possible to convert a RAW image to a DNG file. Specifically, when a manufacturer releases a new type of RAW file, it can take months for applications to be updated to allow conversion to DNG.
The DNG specification itself is also updated periodically to accommodate changing digital imaging needs. Whether that happens fast enough or not is subjective. Recently, there have been discussions about whether a new type of compression should be considered for lossy DNG files, such as HEIC instead of the older JPEG compression.
Alternatives to DNG: JPEG, HEIC, TIFF and RAW
Instead of converting photos from a camera to DNG format, it is easier to store files in any RAW format supported by a camera. Whether it’s Canon’s CR3, Nikon’s NEF, Sony’s ARW or another type of RAW file, this will ensure total quality and ease with the manufacturer’s software. However, compatibility with third-party software may be better with a DNG file.
The native RAW format often takes up a bit more space than a lossless DNG and rarely has a high quality compressed option such as a lossy DNG. While a small manufacturer might abandon its proprietary format, Adobe will continue to support DNG files for the foreseeable future and the format is widely adopted by other applications and operating systems.
TIFF is another lossless format used for photographs, but it is not as efficient as DNG. DNG and TIFF are both owned by Adobe, the latter developed for desktop publishing in the 1980s. Since DNG is Adobe’s newest format and was created with photography in mind, it is likely to be a better choice for storing photos.
JPEG and HEIC are each compressed formats designed to reduce file size while maintaining visual fidelity. While either can produce high-quality final images, zooming in or editing these files will reveal the trade-offs made to free up storage space. Lossy DNG is probably a better choice if there is a need to archive photos that may need to be adjusted or edited in the future.
Which camera brands can capture in DNG format?
Google’s Android operating system supports DNG for RAW photos taken with a smartphone, and many Android camera apps support this feature. Both Samsung and Apple have unique variations of RAW images that incorporate AI processing. Samsung Expert RAW and Apple iPhone ProRAW push the boundaries of smartphone photography and record in DNG format.
Leica, Hasselblad, and Pentax are full-fledged DSLR manufacturers that make cameras capable of capturing photos and saving them directly in DNG format. This means that RAW files from these cameras require no special processing and avoid the extra step of converting to DNG if that is the preferred archiving format.
That said, converting RAW images to DNG files is very fast and can be done individually or in batches with the Adobe Digital Negative Converter application, which is free.
Clearly, the DNG format is here to stay for many years to come and is a reliable way to store RAW photos in the best quality while leaving the door open for future editing. Keeping the best footage as close to the source material as possible allows for greater flexibility in editing.
With the incredible advancements in computational photography, it might be possible to salvage unique photographs that have flaws with upcoming artificial intelligence enhancement technology. DNGs maintain image fidelity and allow for future edits while expanding compatibility and saving storage space. This is why it is such a popular and widely used file format.