Quick start

From download to wing angles in five minutes.

1. Open Rekkefly

Double-click Rekkefly. It opens the first camera it can. If no camera can be opened, the Bogong moth example plays with its own markers, and an amber banner says why. You can learn everything on the moth first, then connect a camera and click Retry camera.

No camera: Rekkefly plays the Bogong moth example with its own markers and says so in an amber banner

2. Light the insect and focus

Rekkefly measures the motion-blur envelope of each wing: the translucent fan a beating wing leaves in a single exposure. Typical rigs film from above or below with the insect backlit, so the body and the blur are darker than the background. Then:

Exposure. Long enough that each frame shows a smooth blur over many wingbeats, short enough that the background is not saturated.
Focus on the wing hinges.
Contrast. The blur should be clearly different from the background. Tick Invert if your insect is bright on a dark background.

3. Place the markers

Drag the dots onto the insect:

Dot	Put it on
Magenta / cyan	The head and the tail. Together they define the body axis
Red / green (inner)	The left and right wing hinges: where each wing turns, at its base
Corner dots	The sector’s angular limits and outer radius, in one drag
Middle dots on an arc	Only the inner or the outer radius
White centre dot	Moves the whole setup

Each sector is an annulus around its hinge. Set the inner radius just past the body and keep the outer radius inside the wing blur. The angular limits should cover the whole stroke with a little margin, while staying clear of the body, the legs and the head. The wings mirror each other while you edit; tick Asymmetric to edit them separately.

Placing the markers explains each choice, with pictures.

4. Save a background (optional)

For a cluttered scene, take the insect out, click Save BG, put the insect back and tick Subtract. Rekkefly then tracks the difference from the empty scene. With a clean backlit background this is rarely needed.

5. Read the angles

The box at the lower left shows the left and right wing angles and L − R, in radians. Angles are 0 when a wing points straight out from the body axis and positive toward the head, as in Kinefly.

The same values are published for every frame:

on ZMQ port 9871, in the Kinefly Docker bridge’s JSON format, so existing Kinefly subscribers keep working;
over UDP to 127.0.0.1:5601, with every detail of the measurement.

Try a receiver:

python3 -m pip install pyzmq
python3 examples/receive_zmq.py --port 9871
python3 examples/live_plot.py --port 9871     # live plot at http://127.0.0.1:8765

See Receiving measurements for both formats and for receivers in other languages.

6. Check the tracking

Open Settings → Show signal diagnostics. Watch L − R while the insect flies: it should be smooth, without spikes when the legs move. The angular profile panel shows exactly which edge was chosen. If something looks wrong, Tuning a rig walks through the fixes.

Everything is saved

Every change is written to the rig’s config file 300 ms after you stop dragging, and when you close the window. Close Rekkefly and open it again: everything is where you left it, including the background. Config files are plain, commented TOML; see Configuration.

A second camera: click New window (several rigs).
Record the session: click Record (recording).
Analyse a recording offline: rekkefly track recording.avi --csv angles.csv (video files).

Rekkefly documentation