Digital Negative (DNG) is an open source, lossless, well defined camera RAW data container with the goal to replace a range of proprietary, closed source raw image containers. It has been developed by Adobe and was launched on September 27, 2004. The launch was accompanied by the first version of the DNG specification,. plus various products, including a free-of-charge DNG converter utility. All Adobe photo manipulation software (such as Adobe Photoshop and Adobe Lightroom) released since the launch supports DNG..
DNG is based on the TIFF/EP standard format, and mandates significant use of metadata. The specification of the file format is open and not subject to any intellectual property restrictions or patents..
Rationale for DNG
Adobe states that, given the existence of a wide variety of camera-brand-specific raw image formats, it introduced DNG as a standardized and backward-compatible universal file format. It is based on the TIFF 6.0 standard. Various professional archivists and conservationists, working in institutional settings have adopted DNG for archival purposes.universal photographic digital imaging guidelines (UPDIG): File formats - the raw file issueArchaeology Data Service / Digital Antiquity: Guides to Good Practice - Section 3 Archiving Raster Images - File FormatsUniversity of Connecticut: "Raw as Archival Still Image Format: A Consideration" by Michael J. Bennett and F. Barry WheelerInter-University Consortium for Political and Social Research: Obsolescence - File Formats and SoftwareJISC Digital Media - Still Images: Choosing a File Format for Digital Still Images - File formats for master archive International Digital Enterprise Alliance, Digital Image Submission Criteria (DISC) Guidelines & Specifications 2007 (PDF)The J. Paul Getty Museum - Department of Photographs: Rapid Capture Backlog Project - Presentation American Institute for Conservation - Electronic Media Group: Digital Image File Formats Archives Association of British Columbia: Born Digital Photographs: Acquisition and Preservation Strategies (Rosaleen Hill)
Objectives The objectives of the DNG file format are:Adobe: Digital Negative (DNG) - The public, archival format for digital camera raw dataAdobe: Introducing the Digital Negative Specification: Information for manufacturers Digital image preservation (sometimes known as "archiving") The US Library of Congress states that DNG is a recommended alternative to other raw image formats.Planning for US Library of Congress Collections: Preferences in Summary The Digital Photography Best Practices and Workflow (dpBestflow) project, funded by the United States Library of Congress and run by the American Society of Media Photographers (ASMP), singles out DNG, and states "DNG files have proven to be significantly more useful than the proprietary raw files in our workflow".dpBestflow: Raw File Formats Easy and/or comprehensive exploitation by software developers Software could support raw formats without DNG, by using reverse engineering and/or dcraw; but DNG makes it easier, and many software products can handle, via DNG, images from cameras that they have no specific knowledge of,Barry Pearson: Support via DNG but not native raws however, any settings stored in the DNG file by software from one company are unlikely to be recognized by a product from a different company. In-camera use by camera manufacturers About 12 camera manufacturers have used DNG in-camera. About 38 camera models have used DNG.Barry Pearson: Products from Camera Manufacturers that support DNG in some way. Raw image formats for more than 230 camera models can be converted to DNG.Barry Pearson: A brief history of DNG Multi-vendor interoperability Unlike the proprietary RAW formats used by most cameras, DNG is supported by multiple vendors, and is readable by a multitude of software applications.
Technical summary A DNG file always contains data for one main image, plus metadata, and optionally contains at least one JPEG preview. It normally has the extension "dng" or "DNG".
DNG conforms to TIFF/EP and is structured according to TIFF. DNG supports various formats of metadata (including Exif metadata, XMP metadata, IPTC metadata) and specifies a set of mandated metadata.Adobe: DNG Specification (Section 4)
DNG is both a raw image format and a format that supports "non-raw", or partly processed, images. The latter (non-raw) format is known as "Linear DNG".Barry Pearson: Linear DNG Linear DNG is still scene-referredCIE: "Scene-referred": image state, scene-referred and can still benefit from many of the operations typically performed by a raw converter, such as white balance, the application of a camera color profile, HDR compositing, etc. All images that can be supported as raw images can also be supported as Linear DNG. Images from the Foveon X3 sensor or similar, hence especially Sigma cameras, can only be supported as Linear DNG.
DNG can contain raw image data from sensors with various configurations of color filter array (CFA). These include: conventional Bayer filters, using three colors and rectangular pixels; four-color CFAs, for example the RGBE filter used in the Sony Cyber-shot DSC-F828; rectangular (non-square) pixels, for example as used in the Nikon D1X; and offset sensors (for example with octagonal pixels) such as Super CCD sensors of various types, as used in various Fujifilm cameras. (Or combinations of these if necessary). DNG specifies metadata describing these individual parameters; this is one significant extension to TIFF/EP.
When used in a CinemaDNG movie clip, each frame is encoded using the above DNG image format. The clip's image stream can then be stored in one of two formats: either as video essence using frame-based wrapping in an MXF file, or as a sequence of DNG files in a specified file directory.
Contrary to its name (Digital Negative) the DNG format doesn't distinguish negative and positive data - all data is considered to be describing a positive image. While this is not an issue when working with images from digital cameras (which are always positive), working with scanned (by a film scanner or DSLR copy stand) film negatives saved as raw DNG files are complicated, because the resultant image is not automatically inverted and thus impossible to be used directly. A way to get around this is using an inverted curve in the photo editing application, however this reverses the effect of the image controls (Exposure, Shadow and Highlight details, etc.) which complicates the photo editing.
Timeline This provides a mixture of the dates of significant events (such as "the first X") and various counts of usage at the anniversaries of the launch (each 27 September).
Counts of products and companies that use DNG in some way are provided primarily for illustration. They are approximate, and include products that are no longer sold. The purpose is mainly to demonstrate that such products and companies exist, and to show trends. Convertible raw image formats (camera models whose raw images can be converted to DNG) only include official support by Adobe DNG converters; not unofficial support by Adobe products (sometimes reaching about 30), nor support by other DNG converters. 2003, late: Adobe started work on the DNG specification. 2004, early: Adobe started talking to other companies about DNG. Launch, 2004, 27 September: Adobe launched DNG. Specification version 1.0.0.0 published. Convertible raw image formats: 60+ 2005, February: Specification version 1.1.0.0 published. 2005, June: First digital back to write DNG, the Leica DMR (Digital Modul R) back for the R8 and R9. 2005, July: First camera manufacturer to provide a DNG converter for its own raw file formats - Hasselblad's FlexColor. 2005, July: First genuine digital SLR camera to write DNG, Hasselblad H2D. 1st anniversary, 2005, 27 September: Camera manufacturers: 4. Camera models: 7. Software products: 70+. Convertible raw image formats: 70+. 2005, October: First compact camera to write DNG, Ricoh GR Digital. 2006, July: First monochrome digital back to write DNG, MegaVision E Series MonoChrome. 2006, September: First rangefinder camera to write DNG, Leica M8. 2006, September: First camera to offer the user a choice of proprietary raw or DNG, Pentax K10D. 2nd anniversary, 2006, 27 September: Camera manufacturers: 8. Camera models: 9. Software products: 120+. Convertible raw image formats: 110+. 2007, May: First raw converter & photo-editor whose first raw-handling release only supported DNG, Pixelmator. 2007, July: First underwater camera to write DNG, Sea&Sea DX-1G. (Based on Ricoh Caplio GX100). 3rd anniversary, 2007, 27 September: Camera manufacturers: 10. Camera models: 13. Software products: 170+. Convertible raw image formats: 160+. 2007, October: First digital scan back system and first 360-degree panorama system to write DNG, Seitz 6x17 Digital and Seitz Roundshot D3 with D3 digital scan back.Seitz Phototechnik: Roundshot D3 with Seitz D3 digital scan backSeitz Phototechnik: Seitz 6x17 Digital with Seitz D3 digital scan back 2008, February: First software on a mobile phone to write DNG, Tea Vui Huang's "DNG Phone Camera" for Nokia. 2008, April: Adobe announces CinemaDNG initiative, using DNG as the basis for the individual raw images of a movie. 2008, May: Specification version 1.2.0.0 published. 2008, September: First movie camera to use DNG as a raw image format, Ikonoskop A-cam dII.Ikonoskop: Ikonoskop A-cam dII 4th anniversary, 2008, 27 September: Camera manufacturers: 13. Camera models: 29. Software products: 200+. Convertible raw image formats: 180+. 2008, September: First DNG converter running on Linux (among several other things), digiKam. 2009, spring/summer: First digiscope with built-in camera to write DNG, Zeiss Photoscope 85 T* FL.Zeiss: PhotoScope 85 T* FL 2009, June: Specification version 1.3.0.0 published. 5th anniversary, 2009, 27 September: Camera manufacturers: 14. Camera models: 38. Software products: 220+. Convertible raw image formats: 230+. 2009, November: First "interchangeable unit" camera to write DNG, Ricoh GXR.Ricoh: Ricoh GXR 2010, February: First 3D movie camera to write DNG, Ikonoskop A-cam3D.Ikonoskop: Ikonoskop A-cam3D 2010, March: First medium format camera to offer the user a choice of proprietary raw or DNG, Pentax 645D. 6th anniversary, 2010, 27 September: Camera manufacturers: 14. Camera models: 47. Software products: 240+. Convertible raw image formats: 290+. 2012, September: Specification version 1.4.0.0 published. 2019, May: Specification version 1.5.0.0 published. 2021, December: Specification version 1.6.0.0 published. 2023, June: Specification version 1.7.0.0 published. JPEG XL added as a compression method. In September, 1.7.1.0 was published as a minor refresh with additional compression parameters. 21st anniversary, 2025, 27 September. 2026, 24 March: DNG is published as the international standard ISO 12234-4:2026 ("Digital imaging — Image storage — Part 4: Digital negative format"). This marks the formal standardization of the Digital Negative format by ISO/TC 42 (Photography), after over 20 years since its initial launch.
During the first 5 years when about 38 camera models were launched that wrote DNG, Adobe software added support for about 21 Canon models, about 20 Nikon models, and about 22 Olympus models.
Reception The reaction to DNG has been mixed. A few camera manufacturers stated their intention to use DNG at launch. They first supported DNG about 9 months after launch. Several more niche and minority camera manufacturers added support after this (e.g. Leica). The largest camera manufacturers have apparently never indicated an intention to use DNG (e.g. Nikon and Canon).
Some software products supported DNG within 5 months of launch, with many more following. Some only support DNG from cameras writing DNG, or from cameras supported via native raw image formats.