DNG to HDR: conversion guide

What happens when you convert DNG to HDR?

RAW development

DNG needs camera- and file-aware development to produce a rendered HDR image. White balance, exposure, camera colour interpretation and, where applicable, demosaicing determine that rendering. The destination does not retain the original RAW development latitude. No development settings or camera support are implemented yet.

Developing into an HDR workspace

RAW capture values are not automatically a finished SDR or HDR picture. An HDR-capable destination can hold a developed high-range image, but exposure, camera calibration, colour space and highlight handling determine which captured information reaches it. The future engine defines that development; neither sensor values nor a wider dynamic range are guaranteed to survive.

Lossless sample storage

RLE preserves stored RGBE bytes; RGBE quantization is not exact storage of arbitrary float RGB. The .hdr format is distinct from the general concept of HDR photography. HDR can store its supported image samples without lossy compression. This applies after rendering and sample conversion: it does not guarantee preservation of source precision, colour space or document structure, and cannot undo earlier losses.

DNG

Source

DNG

Adobe Digital Negative

Compression: Depends on variantTransparency: NoMetadata: Exif, DNG tags

A published TIFF-based format for raw image data, calibration and photographic metadata.

Explore DNG format →

HDR

Target

HDR

Radiance HDR / RGBE

Compression: LosslessTransparency: NoMetadata: Radiance header, EXPOSURE, FORMAT

Radiance pictures with a shared exponent for high-dynamic-range lighting values.

Explore HDR format →

Is DNG → HDR right for you?

Good choice when

HDR fits your delivery use: Lighting environments & radiometry.
You need a developed image for a non-RAW application.
You need a developed image for an HDR working pipeline.
You need lossless storage of the rendered samples supported by HDR.

Probably not when

You need the original sensor data and freedom to redevelop it.
You need untouched camera samples rather than a rendered image.
You expect lossless encoding to restore lost details or editing structure.
You require identical samples without a defined colour and precision policy.

DNG to HDR conversion details

RAW development: DNG needs camera- and file-aware development to produce a rendered HDR image. White balance, exposure, camera colour interpretation and, where applicable, demosaicing determine that rendering. The destination does not retain the original RAW development latitude. No development settings or camera support are implemented yet.
Developing into an HDR workspace: RAW capture values are not automatically a finished SDR or HDR picture. An HDR-capable destination can hold a developed high-range image, but exposure, camera calibration, colour space and highlight handling determine which captured information reaches it. The future engine defines that development; neither sensor values nor a wider dynamic range are guaranteed to survive.
Lossless sample storage: RLE preserves stored RGBE bytes; RGBE quantization is not exact storage of arbitrary float RGB. The .hdr format is distinct from the general concept of HDR photography. HDR can store its supported image samples without lossy compression. This applies after rendering and sample conversion: it does not guarantee preservation of source precision, colour space or document structure, and cannot undo earlier losses.
Sample precision & colour: Source and target sample models can differ in precision, channel layout, colour space and transfer function. Lossless compression only preserves the samples actually encoded; a precision reduction or colour conversion can already change them. The future engine defines numeric mapping, orientation and colour conversion; canonical depth facts are listed below where available.
Metadata & colour: Format support does not guarantee that an export preserves metadata or colour profiles. Retention and colour handling depend on the future converter; its engine is not implemented yet.
Compression: DNG: Depends on variant → HDR: Lossless DNG: Compression, sample type and processing stage are defined by the file and DNG version. Converting a proprietary raw file to DNG is different from exporting a rendered photo, but it does not guarantee preservation of every maker-specific feature. Keep the source when future reprocessing or vendor software matters. HDR: RLE preserves stored RGBE bytes; RGBE quantization is not exact storage of arbitrary float RGB. The .hdr format is distinct from the general concept of HDR photography.
Colour depth: DNG: File-defined sample precision → HDR: 32-bit RGBE / XYZE pixel
HDR: HDR: Radiometric values
Sensor data: DNG: Raw development required
Dimensions: Pixel dimensions, page geometry, rendering resolution, resizing and orientation need explicit converter policies. The future engine has not defined them yet.
Metadata: DNG: Exif, DNG tags → HDR: Radiance header, EXPOSURE, FORMAT. Which fields are copied, rewritten or omitted will depend on the future engine; retention is not implemented yet.

Common questions

Will HDR still be an editable camera RAW?

DNG needs camera- and file-aware development to produce a rendered HDR image. White balance, exposure, camera colour interpretation and, where applicable, demosaicing determine that rendering. The destination does not retain the original RAW development latitude. No development settings or camera support are implemented yet.

Will RAW to HDR preserve the original sensor values?

RAW capture values are not automatically a finished SDR or HDR picture. An HDR-capable destination can hold a developed high-range image, but exposure, camera calibration, colour space and highlight handling determine which captured information reaches it. The future engine defines that development; neither sensor values nor a wider dynamic range are guaranteed to survive.

Does lossless output mean an unchanged source?

RLE preserves stored RGBE bytes; RGBE quantization is not exact storage of arbitrary float RGB. The .hdr format is distinct from the general concept of HDR photography. HDR can store its supported image samples without lossy compression. This applies after rendering and sample conversion: it does not guarantee preservation of source precision, colour space or document structure, and cannot undo earlier losses.

Are bit depth and colour values guaranteed to match?

Source and target sample models can differ in precision, channel layout, colour space and transfer function. Lossless compression only preserves the samples actually encoded; a precision reduction or colour conversion can already change them. The future engine defines numeric mapping, orientation and colour conversion; canonical depth facts are listed below where available.

Will metadata and colour profiles be retained?

DNG: Exif, DNG tags → HDR: Radiance header, EXPOSURE, FORMAT. Which fields are copied, rewritten or omitted will depend on the future engine; retention is not implemented yet.

Explore related DNG and HDR conversions.