================================================================ OG2K fpsup-og2k-v0.1.3a SIGMA fp — 3:2 open gate at 2K, on the sensor's quiet readout ================================================================ WHAT IT IS The sensor's whole 3:2 area recorded as CinemaDNG, at the sensor's native 3x reduction instead of the 2x one OG3K uses: 2016 x 1344 stored RAW matrix · 3:2 · 8, 10 or 12-bit DNG default crop 2000 x 1334 at (8, 5) rolling shutter 8.31 ms 2016 x 1344 is the full 6064 x 4042 sensor reduced by three. It is not a crop: the field of view is the same open gate as OG3K, at a third of the data. Eight frame rates from 23.976 to 100, and **all eight run on the quiet readout** (sensor mode 139). OG3K has to use the noisier fast readout for its 100p; OG2K never does. 12-bit 4.06 MB/frame 24p = 98 MB/s 10-bit 3.39 MB/frame 24p = 81 MB/s 8-bit 2.71 MB/frame 24p = 65 MB/s For comparison OG3K at 24p is 219 MB/s and UHD is 301 MB/s. This is the first open-gate mode an ordinary fast card can sustain. **Firmware Ver.5.02 only.** RAM only: delete AutoRun.txt, remove the battery, and the camera is stock. Nothing is written to flash. **OG2K replaces the third resolution choice.** It cannot coexist with OG3K on the same card: the resolution menu block holds three entries and no more. ---------------------------------------------------------------- FRAME RATES ---------------------------------------------------------------- key vmax tail fps error MB/s 12-bit --------- ---- ---- ------- ------ ---------- OG2K23_98 6748 585 23.97602 0 ppm 97 OG2K24 6741 700 24.00000 0 ppm 98 OG2K25 6471 850 25.00000 0 ppm 102 OG2K30 5398 735 29.97003 0 ppm 122 OG2K48 3370 795 48.00000 0 ppm 195 OG2K50 3235 870 50.00000 0 ppm 203 OG2K60 2699 590 59.94006 0 ppm 244 OG2K100 1617 880 100.00000 0 ppm 406 All eight share sensor mode 139's line time, which is what keeps them on the quiet readout. 119.88p is not offered: the active rows alone would need 598,080 of the 600,600 available cycles. ---------------------------------------------------------------- WHAT CHANGED SINCE v0.1.2a The payload is unchanged. The loader and its second stage are new (2026-09-25), and they change what happens when the camera is switched off. - Every firmware word this card changes is recorded when it loads and written back when the camera powers off. Turning the camera off with the power switch keeps the firmware in memory -- it is a warm restart, not a cold one -- and until now the changes stayed in it, into the next boot and whatever card was in the slot then. Now the camera powers off stock. - This card still starts the ordinary way on every boot: the AutoRun runs and the progress bar shows. The instant start (the card loaded about 1.4 s after power-on, no AutoRun) and the short cold start are packaging, not part of this card: build the card on the fpSup-Merge page and tick Fast Start 2. NOTE The write-back runs as part of a normal power-off. If the camera loses power without one -- a frozen camera with the battery pulled -- it does not run, and the changed words can stay in memory until the camera next starts cold. WHAT CHANGED SINCE v0.1.1a The recording geometry, frame rates and bit depths are unchanged. What changed is how the mode survives the camera around it. 1. MOV no longer freezes the camera. With OG2K selected, switching the recording format to MOV and pressing REC hard-froze the camera (battery pull). OG2K now takes effect only while the format is CinemaDNG: switching to MOV withdraws it, switching back restores it. 2. OG2K is remembered across power cycles. If OG2K was the last resolution chosen and the format is CinemaDNG, the card selects it again after boot. It is skipped -- the camera stays on its own setting -- if a recording is running or still being written. 3. After that automatic restore the live view is already 3:2. Before, the setting was OG2K but the screen stayed 16:9 until a half-press or opening Quick Set. 4. Quick Set opened before the card finished loading no longer stays broken. It used to show only UHD / FHD, plus a stray box reading "Footer14_K", until the next power cycle. The card now has the camera release that stale Quick Set layout, so the next open is built with OG2K in it. 5. The card only restores anything after its payload has loaded completely, and the loader now also invalidates the instruction cache before running the code it read from the card. AutoRun: 104 commands (was 103 -- the added instruction cache step). fpSup.BIN adds three routines (format guard, boot restore, Quick Set release) and two hooks; see MANIFEST.txt. WHAT HAS BEEN VERIFIED FOR THESE CHANGES On a SIGMA fp, Ver.5.02, on the debug build of this card (same payload plus the USB shell), 2026-09-23/24, camera in plain M mode, settings changed by hand in the menu: - item 1 (2026-09-21): MOV + REC does not freeze; back to CinemaDNG and OG2K records 4,143,104-byte frames again. - item 2: OG2K + CinemaDNG -> power cycle -> OG2K restored, and a take recorded without touching the camera was 4,143,104 bytes a frame, 2016x1344 / crop 2000x1334, 12-bit, no dropped frames. FHD chosen -> not restored. OG2K + MOV -> not restored, and the MOV freeze path stays closed. - item 3: the screen came up 3:2 with nothing pressed. - item 4: Quick Set opened early, and kept open across the load, came up with all three choices afterwards. NOT verified: the exact no-shell pair in this folder has not itself been booted; it is the debug build minus the USB worker. Item 4 was checked by eye only -- a run that shows the release step itself firing was not completed. INSTALL ---------------------------------------------------------------- 1. Confirm the camera is a SIGMA fp on firmware Ver.5.02. 2. Power off, REMOVE THE BATTERY, and put the card in a reader. 3. Copy AutoRun.txt and fpSup.BIN to the ROOT of the SD card. 4. Insert the card and power on. Wait for the progress bar and the final message: fpSup-OG2K-v0.1.2a! 5. Select OG2K from MENU -> recording -> resolution, or from Quick Set -> RES. Choose the frame rate and the CinemaDNG quality normally. To remove: delete AutoRun.txt, power off completely, remove the battery, and power on. Warm restart and hot reinstall have not been verified; use a battery-out cold boot. This release carries no development USB shell. ---------------------------------------------------------------- WHAT HAS BEEN VERIFIED ---------------------------------------------------------------- On camera, after a battery-out cold boot. Every geometry figure below was read out of the recorded DNG, not from a menu readback: - 12, 10 and 8-bit all record 2016x1344 with DefaultCropSize 2000x1334 at (8,5). - FHD (1936x1090) and UHD (3856x2170) are unaffected, and switching OG2K -> FHD -> UHD -> OG2K does not corrupt any of them. - live view during recording matches standby: horizontal 1.001x, vertical 1.000x, anisotropy 1.0010, no colour cast, full 3:2 frame. - in-camera playback opens, plays, and does not freeze. - the Settings resolution row reads OG2K. - the playback label reads 2000x1334 in the camera's own style. ---------------------------------------------------------------- WHAT IS NOT VERIFIED — THIS IS A TEST BUILD ---------------------------------------------------------------- - **Highlight headroom and gain state.** OG3K originally lost about 2.7 stops of highlight above ISO 640 because its capture was classified as a stills acquisition. Mode 139 is a monitor-class mode and is expected to behave differently, but this has not been measured. - **Shutter angle.** Mode 139's nominal frame rate metadata is 60 and all eight rates share it, the same structure that caused OG3K's shutter-angle error. The guarded wrapper carries mode 139's timing whitelist, but no shutter readback has been taken at any rate. - **Sustained recording.** The data rate finally fits ordinary fast media, but only short takes have been recorded. - Taking a still photo while OG2K is selected. - Switching CINE/STILL while OG2K remains selected. - Warm restart and hot reinstall. - The exact no-shell pair in this folder is byte-identical to the camera-tested debug build apart from the removed USB worker section, but has not itself been cold-booted. Treat every take as disposable until you have checked it. ---------------------------------------------------------------- HOW IT DIFFERS FROM OG3K ---------------------------------------------------------------- OG3K OG2K sensor mode 98 (÷2 readout) 139 (÷3 readout) raster 3032x2012 2016x1344 recorded 3024x2010 2016x1344 DNG crop 3008x2000 2000x1334 rolling shutter 12.44 ms 8.31 ms 24p 12-bit 219 MB/s 98 MB/s 100p readout fast (noisier) quiet field of view full 3:2 full 3:2 (identical) Both are open gate. OG2K trades resolution for a third of the data, a shorter rolling shutter, and the quiet readout at every frame rate. ---------------------------------------------------------------- WITH THANKS TO VITALY LI ---------------------------------------------------------------- Vitaly Li got open gate out of a SIGMA fp first. https://www.facebook.com/groups/1124721801045663/permalink/3266113850239770/ ---------------------------------------------------------------- FILES ---------------------------------------------------------------- AutoRun.txt boot loader and progress display fpSup.BIN OpenGate recording core plus native UI runtime MANIFEST.txt exact hashes, memory map, and verification boundary README.txt this file Only AutoRun.txt and fpSup.BIN go on the SD card.