GR4-LUTSmith
Your own colour look, from a .cube LUT, inside your RICOH GR IV or GR IV HDF.
- Custom firmware
- Stable
- Medium brick risk
- Reversible
This project hasn't been claimed by its maintainer yet, so its details come from the community. Is it yours? Claim it
GR4-LUTSmith 2.2.0 — the GR IV HDF
Put the look of a .cube LUT into your RICOH GR IV or GR IV HDF, in a window: no terminal, nothing else to
install. The app makes exactly the same firmware as the command line from the same LUT and choices.
New in 2.2.0: the GR IV HDF
- One file for both cameras. RICOH ships one 1.11 update for the GR IV and the GR IV HDF, and the firmware GR4-LUTSmith makes now works on both. There is nothing to choose: start from RICOH's official 1.11 file as before.
- Your look opens at 0 on the HDF too. Until now, on a GR IV HDF a personal look opened with RICOH's slider settings for its slot (for example Contrast +3 on Positive Film) instead of 0. Now every slider starts at 0 and grain is off, as on the GR IV. Tested on a GR IV HDF 1.11: works.
- Nothing changes on a GR IV. A 2.2.0 file is the 2.1.1 file of the same looks plus only the HDF's slider settings; a GR IV reads exactly what it read with 2.1.1.
- Files made before 2.2.0: fine on a GR IV. For a GR IV HDF, build the same
look.jsonagain; Check a firmware file (orcheck) tells you which files need it. - Never on a GR IV Monochrome or any other model.
The README (all 8 languages) also has a testing-status entry for colour after the curves (tested on a GR IV 1.11).
Earlier: 2.1.1 the guide in 8 languages; 2.1.0 several turns at once; 2.0.2 new app icon.
Download
| Computer | File |
|---|---|
| Mac with Apple silicon (M1 or later) | GR4-LUTSmith-2.2.0-macOS-AppleSilicon.zip |
| Mac with an Intel processor | GR4-LUTSmith-2.2.0-macOS-Intel.zip |
| Windows 10 or 11 (64-bit) | GR4-LUTSmith-2.2.0-Windows-x64.zip |
Needs macOS 12 or later, or Windows 10/11 (64-bit), and a GR IV or GR IV HDF on firmware 1.11.
The app is free and not signed with a paid certificate, so your computer asks once whether you trust it: on macOS, System Settings → Privacy & Security → Open Anyway; on Windows, More info → Run anyway. Step by step: Open it the first time.
The command line stays available (The command line).
Check your download
Each zip was built and signed by this repository's own build on GitHub. With the GitHub CLI:
gh attestation verify GR4-LUTSmith-2.2.0-macOS-AppleSilicon.zip --repo lemonadesaltbagel/GR4-LUTSmith
SHA256SUMS lists every file's checksum.
Unofficial, at your own risk. Not made or endorsed by RICOH IMAGING. Read Before you start and Risks before installing anything. To go back, install RICOH's official 1.11 firmware the normal way.
Before you start
- How hard is it?
- MediumInstall an app on your computer and follow its steps.
- What you need
- Comfort with the command line
- A computer
- An SD card or USB stick
- Can it break my device?
- Small chance of trouble, with a way to recover. It may void your warranty.
- Can I undo it?
- Yes. You can go back to the official software.
Did it work for you?
Did GR4-LUTSmith v2.2.0 work on your Ricoh GR IV?
No reports yet for v2.2.0.
One-tap reports from owners. Bricked reports are checked before they count.
Compatibility
Devices: Ricoh GR IV.
No compatibility information yet.
Getting started
From the project's README ("Put it on the camera"):
The same for a firmware from the app and from the command line.
Copy it to the SD card
Format the SD card in the camera.
Copy fwdc248b.bin (from the command line: output/mylook/fwdc248b.bin) to the top level of the card: not into a folder, and keep the name exactly fwdc248b.bin.
Update the camera
Insert the fully charged battery and the SD card.
Start the firmware update from the camera's setup menu, as described in RICOH's official GR IV / GR IV HDF firmware update instructions.
The camera shows an update from version 1.11 to version 1.11. This is expected: the modified firmware keeps the version number. Confirm the update.
> [!CAUTION] > Do not turn the camera off, open the battery or card door, or remove the > card until the update has finished and the camera has restarted.
Shoot
- Open Image Control and choose High Contrast (after the first "HDR Tone"). It is in colour now. If you chose another slot, choose that entry instead.
- The firmware version still shows 1.11. That is normal.
- Delete fwdc248b.bin from the card (or format the card) so the update is not started again by accident.
To change to another LUT later, make a new firmware from the official file and install it the same way.
Going back to the official firmware
Repeat steps 1–2 with the official fwdc248b.bin from RICOH instead. The camera again shows 1.11 → 1.11; confirm it, and your camera is back to stock.
Risk and recovery
- Brick risk
- Medium
- Reversible
- Yes
- Voids the warranty
- Yes
- Requires opening the device
- No
From the project's README ("Going back to the official firmware"):
Repeat steps 1–2 with the official fwdc248b.bin from RICOH instead. The camera again shows 1.11 → 1.11; confirm it, and your camera is back to stock.
Releases
| Version | Name | Released |
|---|---|---|
| v2.2.0 | —Latest | 11 October 2026 |
| v2.1.1 | — | 11 October 2026 |
| v2.1.0 | — | 11 October 2026 |
| v2.0.2 | — | 11 October 2026 |
| v2.0.1 | — | 11 October 2026 |
| v2.0.0 | — | 10 October 2026 |