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.dng File Extension

Learn what a .dng file is, how to open Digital Negative photos, how Poly supports them, and which format to use when sharing.

File extension details for .dng

Full Support
File typeAdobe Digital Negative image
MIME type
image/x-adobe-dng
EncodingBinary, TIFF-based camera RAW container with image data, metadata, profiles, and optional previews
Operating systemsWindows, macOS, Linux, iOS, iPadOS, Android
Opens withAdobe Lightroom Classic, Adobe Camera Raw, Adobe DNG Converter, Apple Photos
Poly supportYes. Poly provides rich support for DNG photographs.
Indexed by PolyYes. Poly indexes filenames, available camera metadata, color, and visual similarity.
Preview in PolyYes. DNG files open in Poly's image viewer.
Poly agentYes. The Poly agent can understand the visible photograph.

What kind of file is a .dng?

A .dng file is a Digital Negative image. Adobe designed this documented container for camera RAW data, capture metadata, color profiles, and optional rendered previews. It can store mosaiced sensor samples or linear image data that has already been demosaiced.1

The conventional image/x-adobe-dng MIME type is not registered by IANA.2 DNG extends TIFF, so it begins with an ordinary little-endian or big-endian TIFF header: 49 49 2A 00 or 4D 4D 00 2A. Those bytes are not unique to DNG. Reliable identification also checks its TIFF directories and the DNGVersion tag.13

Renaming a TIFF, JPEG, NEF, or another camera RAW file to .dng does not convert it. A valid DNG needs the expected structure and DNG-specific tags.

How do I open a .dng on my computer?

Use a RAW processor when you want to adjust the underlying image data:

  • Windows or macOS: Adobe Lightroom Classic, Camera Raw, and Photoshop support DNG. Adobe DNG Converter can translate supported camera-specific RAW files and target older DNG compatibility levels.45
  • macOS, iOS, and iPadOS: current Apple operating systems include basic DNG support for compatible photo apps.6
  • Linux: darktable and RawTherapee support many DNG files, although newer compression and camera features can require a recent version.
  • Android: Lightroom and other RAW-capable photo apps can open supported DNG files.

Web browsers do not normally display DNG as a web image. Export a JPEG, WebP, AVIF, or PNG copy for online use.

Poly support for .dng

Poly gives DNG photographs thumbnails, an in-app image preview, available Exif metadata, visual search, and agent understanding. You can find a capture by filename, metadata, color, or visible content, and the Poly agent can reason about the displayed photograph.

The preview is a rendered view, not a new development of every sensor sample. Use a dedicated RAW editor for white balance, demosaicing, camera profiles, highlight recovery, and complete metadata inspection. Words photographed inside an ordinary DNG are not indexed as document text. Review GPS, timestamps, camera details, and authorship metadata before sharing an original.

History of .dng

Adobe published DNG 1.0.0.0 in September 2004 as a documented alternative to model-specific camera RAW containers. Its current public specification is DNG 1.7.1.0, dated September 2023.4

In March 2026, ISO published DNG as ISO 12234-4:2026, Digital imaging, Image storage, Part 4: Digital negative format.7 DNG files also record a backward-version requirement, so older software can reject a valid file that uses newer compression or features.1

Working with .dng and alternatives

Keep the DNG as a master when you may want to revise the raw development later. Export a copy suited to its destination:

FormatBest forTradeoff
JPEGEmail, galleries, and broad compatibilityLossy and usually 8-bit
TIFFHigh-quality interchange and further editingLarge rendered file
PNGLossless sharing of finished pixelsLarge for photos and no longer RAW
Camera-original RAWPreserving manufacturer-specific dataLess portable and camera-dependent

Adobe warns that conversion from a proprietary RAW file may omit some proprietary metadata. A DNG can embed the complete original file, but that increases its size.5 For an important archive, keep the untouched source until you have verified the converted DNG in every application your workflow requires.

Footnotes

  1. Adobe. Digital Negative (DNG) Specification, Version 1.7.1.0. Defines the TIFF-based structure, image models, DNG tags, previews, metadata, and version fields. ↩ ↩2 ↩3
  2. Internet Assigned Numbers Authority. Media Types Registry. The image registry contains no image/x-adobe-dng or image/dng registration. ↩
  3. Library of Congress. Adobe Digital Negative (DNG), Version 1.6. Documents the TIFF headers and DNGVersion-based identification. ↩
  4. Adobe. Digital Negative (DNG), Adobe DNG Converter. Publishes the current specification and records the September 2004 DNG 1.0.0.0 example. ↩ ↩2
  5. Adobe. Adobe Digital Negative Converter. Documents compatibility targets, conversion choices, proprietary-metadata limitations, and original-file embedding. ↩ ↩2
  6. Apple Support. Digital Camera RAW Formats Supported by Apple Operating Systems. States that current Apple operating systems include basic DNG support. ↩
  7. International Organization for Standardization. ISO 12234-4:2026, Digital Negative Format. Records the March 2026 publication of the first edition. ↩
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