# Radiance High Dynamic Range image file — file signature 23 3F 52 41 44 49 41 4E 43 45 0A at offset 0

For Radiance High Dynamic Range image file, hex signature is 23 3F 52 41 44 49 41 4E 43 45 0A; offset is 0; extension is hdr, verified against its source on 2026-09-22.

- **Hex signature:** 23 3F 52 41 44 49 41 4E 43 45 0A _(verified: appears in the quote below)_
- **Offset:** 0 _(verified: appears in the quote below)_
- **Extension:** hdr _(verified: appears in the quote below)_
- **Format:** Radiance High Dynamic Range image file _(verified: appears in the quote below)_

## What the source says

> 23 3F 52 41 44 49 41 4E 43 45 0A | #?RADIANCE␊ | 0 | hdr | Radiance High Dynamic Range image file |

## Source

- https://en.wikipedia.org/wiki/List_of_file_signatures

Last verified: 2026-09-22. Review by: 2027-09-22.
Part of [File format magic numbers](https://referencesource.org/file-format-signatures/).