OpenEXR image
ImagesEXR is OpenEXR, used for wide brightness ranges and channels such as depth or render passes. Dark or black output may reflect display transforms or channel selection rather than corruption. Separate numerical compositing sources from display images.
- Main use
- Storing HDR renders and compositing channels
- Data type
- Binary data / document
All sections, questions and sources
Content reviewed： · Editor：Kai
Example: a practical checking sequence
Example: an EXR render looks dark while its PNG looks normal. Check RGB selection, view transform and exposure. Do not overwrite it with an 8-bit image. Export a separate viewing copy and retain depth/mask passes needed for compositing.
Opening steps
Choose your environment or purpose to see its steps.
Menu labels and support vary by app, OS and version. Preserve the original before making changes.
Troubleshooting by symptom
- Black or dark: check scene-linear interpretation, view transform and exposure.
- No apparent RGB: inspect channel names; some files contain only depth or other data.
- Color differs: compare production color space and viewer settings.
- Large file: check dimensions, channels, half/float storage and compression.
- Compositing changes after PNG export: depth or HDR values may be lost; use the original EXR.
EXR → PNG / JPEG for display
- Select RGB and establish appearance with the intended view transform and exposure.
- Export a display copy and configure alpha when required.
- Verify in an ordinary viewer and retain the compositing source.
Ordinary output does not preserve HDR values or additional passes. Check color management to avoid applying display transforms twice.
Numerical brightness versus display
EXR often stores scene-linear rendering data, but the suffix alone does not establish color space; check metadata and production settings.
Preserving numerical values and mapping them for display are separate operations.
Source for these steps：OpenEXR · Scene linear
Preserve channels beyond RGB
Depth, normals, masks and render passes support compositing adjustments; exported RGB does not replace them.
- Record required pass and channel names.
- Check multilayer support in the receiving tool.
- Check whether compression is lossless for the intended use.
Source for these steps：OpenEXR · Technical introduction
Related-format differences
| Format / purpose | Use and preserved information |
|---|---|
| EXR | Production source for HDR values and multiple passes. |
| HDR | Radiance imagery and other uses; not identical to EXR. |
| PNG | Display-oriented copy. |
Handling and security
Inspect channels and metadata before sharing unreleased production assets, and use updated trusted tools.
Questions and answers
Is a dark EXR corrupted?
First check view transforms and channel selection.
Is every EXR 32-bit?
Channel types can differ, including half and float.
Can PNG replace it for compositing?
Not equivalently when HDR values or passes are required.
What if I see only RGB?
Check app support and the source pass inventory.
What should I decide before JPEG export?
View transform, exposure, output color space and purpose.
Format facts: name, steward and MIME type
- Formal name
- OpenEXR
- Steward / specification
- Academy Software Foundation / OpenEXR project
- MIME type
- Check the producer or implementation; do not assume a single universal MIME value.
Primary and official sources
- Project documentationTechnical introduction
HDR pixels, channels and compression
OpenEXR · Link checked： - Project documentationScene linear
Scene brightness and display transforms
OpenEXR · Link checked： - Software documentationSupported image formats
TGA, JPEG 2000, EXR and HDR input/output
Blender · Link checked： - Software documentationSupported file formats in Photoshop
Photoshop supported image and editing formats
Adobe · Link checked：