### Overview

Every group-statistics number on the 2026 plots and tables begins as a
clicked pixel on a target photograph. This page describes the path from a
JPG impact image to an inch-space coordinate.

The same pipeline backs both the
[component-test restorative-lift protocol](/research/arrow-study-2026/methods/components-restorative-lift/)
and the [Front-of-Center test](/research/arrow-study-2026/methods/foc/).
There is no shooting-machine bias unique to one and not the other;
whatever differences appear between tests originate in the bow setup and
arrows, not in how the resulting photographs are measured.

All processing described here was done with custom-developed software
written in Python.

### Reference Markers

Every photo is composed so that the same set of reference markers is
visible in every frame. Together they let any photo recover its own
real-world coordinate system without relying on photo-to-photo
continuity. This is important because the camera, target, or shooting
machine may move slightly throughout the session.

Each impact and each reference marker listed below is marked by hand.
Downstream processing reads only the resulting pixel coordinates plus the
photo's embedded timestamp.

[Figure: Equation]

A single photo can contain both <Equation inline>fp</Equation> and{" "}
[Figure: Equation]