GR4-GF2Unlock
The GR III's GF-2 Flash Mode, on your RICOH GR IV. Focus on your subject; the camera sets the flash exposure.
- Custom firmware
- Beta
- 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
Before you start
- How hard is it?
- HardUses the command line or developer tools.
- 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-GF2Unlock work on your Ricoh GR IV?
No reports yet.
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"):
Copy it to the SD card
Format the SD card in the camera.
Copy output/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 firmware update instructions.
The camera shows an update from version 1.11 to version 1.11. This is expected: the GF-2 Flash Mode 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
With the camera and the GF-2 both off, slide the GF-2 fully into the hot shoe, then switch both on.
Shooting menu → Flash Mode → GF-2 Flash Mode.
Set Flash Output to Auto or 1/1 for full power, or 1/4.
Focus on your subject and shoot.
- 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.
Going back to the official firmware
> [!IMPORTANT] > First set Flash Mode to anything other than GF-2 Flash Mode, for example > Flash On. Do the same in every custom mode (C1, C2, …) that uses it. The > official firmware has no GF-2 Flash Mode setting.
Then repeat steps 1–2 with the official fwdc248b.bin from RICOH instead. …
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"):
> [!IMPORTANT] > First set Flash Mode to anything other than GF-2 Flash Mode, for example > Flash On. Do the same in every custom mode (C1, C2, …) that uses it. The > official firmware has no GF-2 Flash Mode setting.
Then 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.