Current Firmware: v001.006.107 (12/12/25)
Released: December 12, 2025
- Fix bug where the Celestial would sometimes deliver a test flash after holding the power button to turn on the unit.
- Make test flash button more responsive and allow for a slightly longer press
- Adjusted Sony TTL performance so maximum power level could be reached in HSS.
Updating Your Celestial's Firmware
WHAT YOU NEED:
- HUB Remote
- Paul C. Buff Flash Control APP
Once you have downloaded the app, please follow its instructions on updating your firmware. For more information on navigating the Flash Control App, please click here.
Celestial Firmware History
A list of firmware updates with details and release dates. The firmware 'v001.005.102' update includes ALL PREVIOUS UPDATES that have been released.
- Fix bug where the Celestial would sometimes deliver a test flash after holding the power button to turn on the unit.
- Make test flash button more responsive and allow for a slightly longer press
- Adjusted Sony TTL performance so maximum power level could be reached in HSS.
- Improved TTL consistency and performance for Sony, Canon, and Nikon.
- Added SL1 and SL2 options for Slave Eye triggering. SL1 mode operates by triggering on any flash picked up by the slave eye, and is the mode currently used by the light. SL2 mode is to work in sync with TTL flashes. The flash unit senses the on-camera preflash, releases a low power flash so the camera is aware of its presence, and then fires the main flash, as set manually, in sync with the camera's shutter.
- To enter SL2, navigate to where you would change the sync mode on your flash unit. LINK: If the sync mode is slave or slave/remote, then SL1 or SL2 will be displayed on the unit. Press the power button to toggle between the two. CELESTIAL: If the sync mode is slave or slave/remote, then SL1 or SL2 will be displayed on the unit. Press the encoder button to toggle between the two. Use the menu button to confirm your change and exit the menu.
- Fixed bug where the recycle indicator would sometimes beep twice.
- Fix bug in UI so that blinking segments are consistent. Previous versions would have non-uniform blinking on the selected segment.
- Now compatible with the Sony HUB in HSS, TTL, and manual exposures.
- Enables faster scrolling through flash and model power. By holding down the encoder button for 3s, the user can then adjust the flash or model power by full-stop increments instead of 0.1 stops.
- Fixed bug where the flash unit would occasionally detect an error and force the unit off when the error was not present.
- Fixed bug where if a flash unit was remotely toggled off and back on too quickly, it would turn off the internal radio and stop the user from turning the unit back on remotely.
- Removed bug that would occasionally display a -0.2 error on the unit and power down the unit unexpectedly.
- Fixed bug where the battery would fail to communicate the proper state of charge information when first powering on the unit.
- Improved performance when controlling the slave eye using remote device.
- Please note this firmware update will take ~ ½ the amount of time as previous Celestial updates. However, your HUB must be on the latest firmware to complete the update.
- Improved TTL performance on both Nikon and Canon systems.
- Improved compatibility with FusionTLC’s Raven. The flash unit’s configuration is no longer overwritten by the Raven – flash mode and model mode now remain the same when powering on via the Raven.
- Deactivate Zone D (CH 4, 8, 12, 16) TTL as it is not supported by camera manufacturers.
- A user can shut down the battery completely by holding down the power and encoder button for 5 seconds. The only way to wake the battery is by connecting it to the charger.
- Updated the battery indicator on the user interface to display battery life more accurately.
- Fixed bug where battery display would come up showing less than full after charging the battery overnight.
- Improved color consistency and output power in Color Mode
- TTL zones have been remapped. Zone A = CH 1, 5, 9, 13. Zone B = CH 2, 6, 10, 14. Zone C = CH 3, 7, 11, 15. Zone D (if supported by camera) = CH 4, 8, 12, 16.
- TTL is now compatible to be used with with FusionTLC’s Raven. See their website for a list of supported camera models.
- Fixes bug when communicating with FusionTLC’s Raven where it could not toggle lights in CH 2, 3, or 4 into HSS mode by toggling the shutter speed above X sync on your camera.
- Fix bug where unit leaves thermal mitigation mode when the battery overheats
- Fix bug where rotary encoder moves 0.1 f-stop from the previous value when the unit is first powered on