Adobe introduced the Digital Negative format in 2004 with a straightforward argument: the photography industry had a proprietary RAW problem. Every camera manufacturer was writing its own undocumented raw format — Canon’s CR2, Nikon’s NEF, Sony’s ARW — and long-term archival of those files depended entirely on those companies continuing to support their own legacy software. Adobe proposed DNG as an open, documented alternative. For two decades it remained influential but never quite official. That has now changed.
The International Organization for Standardization has formally adopted DNG as an ISO standard for raw image data — a status that elevates it from “widely supported open format” to “internationally recognized specification.” The distinction sounds administrative, but for anyone who cares about file longevity, interoperability, or institutional archiving, it has real downstream effects.
What DNG Actually Contains (and Why the Format Was Always Different)
Understanding why this standardization matters requires a clear picture of what DNG does differently from a typical camera-manufacturer raw file.
A raw file — regardless of the brand suffix — stores the unprocessed output of the image sensor: linear light values, mosaic filter pattern data, and the metadata the camera recorded at capture (shutter speed, ISO, white balance as-shot, lens information). The “development” step that turns that data into a viewable image happens in software, not in-camera. What varies enormously between manufacturers is how that data is packed, encrypted, or structured inside the container.
DNG resolves this by specifying a container built on the TIFF-EP foundation with a documented, publicly available structure. The raw sensor data goes into specific tags. Metadata follows EXIF and XMP conventions. A thumbnail and a full-size preview are embedded by default. Crucially, the specification is published: any developer can write software to read or write a compliant DNG without signing an agreement or reverse-engineering undocumented chunks.
The format also has an interesting dual life. Many cameras — particularly from Leica, Hasselblad, Ricoh/Pentax, and some DJI drone lines — shoot natively to DNG rather than a proprietary raw. And Adobe’s DNG Converter has long offered a path to wrap most other manufacturers’ raws inside a DNG container, optionally embedding the original raw data so nothing is discarded.
What ISO Standardization Actually Changes
Formal standardization through ISO does several concrete things.
First, it creates a stable, version-controlled specification that is maintained independently of any single vendor. Adobe originated DNG and has continued developing it, but an ISO-standardized format has governance that doesn’t depend on one company’s continued interest or financial health. For institutional buyers — museums, national archives, government photography departments — this matters significantly. Many procurement policies explicitly require open or standardized formats; DNG now qualifies in a way that CR2 or NEF never could.
Second, standardization increases the pressure on software developers and platform vendors to maintain compliant implementations. This is not a guarantee, but ISO status creates accountability that informal openness does not. A developer ignoring an undocumented proprietary format has no external pressure; a developer ignoring an ISO standard has to explain that decision.
Third, the specification provides a legal baseline for what “DNG” means. Before standardization, the only authoritative definition was Adobe’s own documentation, which left room for ambiguity about which features were core versus optional extensions. An ISO standard nails down what conformance requires.
What It Does Not Change
Standardization does not immediately solve the practical reality of camera manufacturer adoption. Canon, Nikon, and Sony continue to ship cameras that write proprietary raws. That is unlikely to change quickly — manufacturers have competitive reasons to keep some raw format differentiation, and the tooling ecosystems around their native formats are mature. Photographers who shoot CR3, NEF, or ARW today are not going to find those files suddenly obsolete, and their raw processing software is not going to stop supporting them.
It also does not change DNG’s existing technical limitations relative to some native raws. When you convert a manufacturer’s raw to DNG, you are repackaging the data — the embedded original can preserve every byte, but the conversion process itself introduces decisions about which proprietary metadata to carry forward. Some camera-specific lens correction tables, focus maps, and bracketing metadata may not survive intact depending on the conversion path. This has always been a tradeoff worth understanding before committing an entire archive to DNG.
The file size question remains what it was: DNG files are typically larger than some competing raws when lossless compression is applied, though DNG does support a lossy compression option (using JPEG 2000 wavelet compression for the raw data) that reduces file size at the cost of some raw data fidelity. Neither option is new; ISO standardization doesn’t alter these encoding choices.
The Long-Game Argument for DNG
The clearest beneficiary of this standardization is anyone thinking in decades rather than editing cycles.
A raw file’s value degrades precisely to the degree that software stops supporting it. Kodak’s proprietary raw formats from the 1990s are already difficult to process correctly in contemporary software. The same fate is plausible for any format whose specification exists only inside a manufacturer’s codebase. DNG’s original 2004 argument — that photographers deserved a format whose readability didn’t depend on corporate continuity — is now underwritten by an international standards body.
For working photographers, the practical decision of whether to convert to DNG in-workflow or keep native raws is unchanged by standardization. The tradeoffs around metadata fidelity, storage overhead, and software compatibility all still apply. Our File Formats coverage has more on how those format-level decisions play out across different shooting and archiving scenarios, including the growing influence of HEIF-derived containers in camera workflows — a comparison we examined in detail in HEIF vs. JPEG: Which Camera Format Should You Use?.
The concrete next step: if you maintain a long-term archive and haven’t reviewed your raw storage strategy recently, check whether your archiving institution or backup workflow has a stated policy on format standards. DNG’s new ISO status may now satisfy requirements that previously pushed archivists toward TIFF or other already-standardized containers — and that is worth confirming directly against your institution’s current documentation.