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Linear DNG
files explained

Byronetmedia

Your path to the ultimate
image quality

Discover the benefits
to your RAW photo workflow

Here you will learn all about the Linear DNG files that PureRAW produces: what these special RAW files are, how they work, and how they can improve the quality of your photos — all while continuing to use your regular photo editing software.

From ‘RAW’
to ‘RAW plus’

As part of its revolutionary workflow, DxO PureRAW takes regular RAW files from your camera and pre-processes them to create Linear DNGs. DNG — or Digital Negative — is an open format of RAW file, and Linear DNGs retain this flexibility. These files can be edited just the same as normal RAWs but have significant advantages.

In fact, the best way to think of Linear DNG is ‘RAW plus’. It’s a format that delivers everything great about shooting and editing RAW files, while allowing DxO PureRAW to create an extra level of quality that your camera and regular software can’t supply alone.

What is
RAW?

Let’s start with a quick reminder of how regular RAW files work.

If you already shoot RAW, you’ll know that a RAW file is unprocessed image data from the camera’s sensor. Each RAW file is unique to its camera brand and model; as such, a RAW file cannot be viewed on a regular device (e.g., a computer screen) without first being processed or converted into a common format such as JPEG or TIFF.

Even when you preview a RAW file on your camera’s rear screen or using a file browser file browser, you’re seeing a processed version.

So what’s the advantage? The benefit is in a RAW file’s potential for editing. Processing it outside of the camera leads to higher image quality and means that more expansive creative decisions can be made.

Petr Bambousek
Violet-eared hummingbird
Olympus EM-1 Mark III
200mm f/2.8
ISO 3200 - 1/800 - f/2.8 - 200mm
DxO PureRAW - DxO PhotoLab

Why RAWs
can do more

The way that data is recorded within a RAW file allows greater latitude in adjustment compared to a JPEG. For instance, during a RAW conversion, you’ll be able to lighten or darken general exposure up to a point and correct specific tonal zones like highlights and shadows, usually without losing detail in those areas.

White balance is also editable, meaning you can ensure color is neutral and lifelike — even if it was set incorrectly at the time of shooting. None of these things are possible to the same degree in a JPEG file.

Why isn’t this possible, you may ask? As part of a RAW’s conversion to JPEG, certain aspects of its data are locked and no longer have the same latitude for adjustment. These processes are called demosaicing and denoising. It’s important to note that once a RAW is demosaiced and denoised, its flexible data become fixed, and therefore editing potential is reduced.

If you want maximum control, it makes sense to shoot and edit RAWs before editing and converting them to JPEGs. So why are Linear DNGs different?

Stefan Forster
Between Narsaq and Kulusuk in Greenland
DJI Mavic 3
24mm f/2.8
ISO 100 - 1/80 - f/2.8 - 12mm
DxO PureRAW - Adobe Lightroom

For the first image, the photographer applied a preset to the original RAW file. For the second image, the photographer applied the same preset to a JPEG. Notice the difference in detail in the shadows and highlights.

How the Linear DNGs used
by DxO PureRAW improve RAWs

As mentioned, pivotal parts of RAW conversion are demosaicing and denoising; however, as these are automatic processes, they tend to go unnoticed.

Demosaicing is the process by which the raw sensor data and its pixel values for red, green, and blue are interpreted into what we perceive as natural and lifelike colors on screen. Denoising is the removal of inaccurate pixels created as a result of interference and heat inside your camera during an exposure, which can be amplified in photos made at higher ISOs.


Together, these processes produce the best possible version of an image in terms of technical quality. In that way, they are separate from any creative changes you might make, such as exposure or color.

Demosaicing and denoising have to be completed during a RAW conversion before any other editing takes place — but what’s surprising to many photographers is that the quality of those processes is not standardized, which means some software perform them better than others.

How Linear DNG
fits into your workflow

Let’s use the below image to demonstrate the utility of Linear DNG. As well as making this ISO 2500 RAW file look as if it were shot at ISO 1000, DxO PureRAW also creates a sharper, more detailed image — one that appears automatically in your Adobe Lightroom Classic catalog, complete with any existing edits.

Jimmy Beunardeau
Taïwan
NIKON D850
24-70mm f/2.8
ISO 2500 - 1/80s - f/2.8 - 70mm
DxO PureRAW - PhotoLab

Best of all, Linear DNGs can become a part of your photographic workflow without disruption.

So, with the accuracy of your RAW files improved by DxO PureRAW, they can be loaded into any RAW editing software, allowing you to keep your existing photographic workflow.

What’s more, if you’re using Lightroom Classic, your RAW files can be processed into improved Linear DNGs straight from the menu and returned to your Library, complete with any previous edits still in place.

Conclusion

At DxO, we’ve led the research on how to denoise and demosaic RAW files, guaranteeing photographers the best possible results. If you’re using DxO PhotoLab 8 or DxO PureRAW 5, you can be certain to get perfectly processed images thanks to cutting-edge science.


For the passionate photographer.

Learn more about DxO