fp-l-tether

Open-source tethered shooting for the Sigma fp L on macOS

Sigma fp L のテザー撮影を macOS で動かすオープンソース実装

Python 3.10+ macOS 12+ MIT License Status: Beta

What it does

fp-l-tether is a self-contained tethering daemon and floating control panel for the Sigma fp L on macOS. Shots land directly in Lightroom Classic via Auto Import. Used daily by the author for studio product and art-repro photography.

Live View at 10 fps with click-to-AF on the LV image
Detachable LV window (⌘D) — pop Live View into a resizable 3:2 window for art-repro or iPad-via-Sidecar workflows
RGB histogram overlay with highlight / shadow clipping markers
Composition grid — thirds / golden ratio / full alignment grid
Floating control panel that follows you across macOS Spaces and Lightroom fullscreen
Lightroom Classic Auto Import integration — every shot lands in your catalog automatically
Auto USB recovery — when the fp L's bulk endpoint wedges (a known firmware quirk), the daemon force-re-enumerates the device via IOKit in ~4 seconds
Persistent settings cache — ISO, shutter, aperture, white balance, format, and LV window state stay remembered across disconnects
JPG / DNG / DNG+JPG capture with dual-file extraction
Preferences window (⌘,) — change watch folder, filename pattern, and Lightroom mode without editing TOML
質実剛健 design — anodized-black + amber accent + SF Mono hero values, inspired by the Sigma fp's industrial aesthetic

Screenshots

fp-l-tether floating control panel with Live View, RGB histogram, exposure controls, and Shoot/AF buttons — Floating control panel — Live View, histogram, exposure controls, Shoot/AF

Detached Live View window at large size with the compact panel showing exposure controls only — Detached LV window (⌘D) for art-repro and iPad-via-Sidecar workflows

Quick start

git clone https://github.com/iochan-ship-it/fp-l-tether.git
cd fp-l-tether
python3 -m venv venv
source venv/bin/activate
pip install -e .

Connect the Sigma fp L in Camera Control USB mode, then:

# Kill macOS's built-in PTP daemon first
sudo killall ptpcamerad

# Launch the daemon + floating panel
sudo venv/bin/fp-l-tether start

sudo is required because libusb has to detach the kernel driver from the camera's PTP interface. See docs/SETUP for the full permission model.

What's working / not working

Feature	Status
Capture (single shot, PC-triggered)	✅ Works
Capture (camera-button-triggered)	✅ Works
Live View (10 fps)	✅ Works
Click-to-AF on Live View	✅ Works
ISO / SS / Av / WB / Format / Resolution control	✅ Works
Lightroom Auto Import	✅ Works
Auto USB recovery from wedge	✅ Works (~4 s)
Settings preservation across reconnects	✅ Works
Detachable LV window + Sidecar (iPad as display)	✅ Works
Burst / continuous capture	⚠️ Single shot only — continuous on roadmap
Video / movie tether	❌ Not supported, no plans
Linux / Windows	❌ macOS only (IOKit-dependent recovery)

Documentation

Why this project

The Sigma fp L is a remarkable little camera that deserves a great tethered shooting experience. This is a community-built option for photographers who want their fp L shots to land directly in Lightroom Classic and who enjoy customizing their tools.

Acknowledgements

This work would not have been possible without:

libgphoto2 (LGPL-2.1+) — PTP wire-protocol reference
sigma-ptpy by makanikai — independent Python implementation cross-referenced for DataGroup FieldPresent bitmasks
All the fp / fp L owners who posted USB captures and protocol notes on GitHub issues, Reddit r/SigmaFP, and DPReview over the years