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Chart Help: Map Projections

Endeavour has several different projections available. At the moment, all available projections are azimuthal (projecting the celestial sphere directly onto a flat plane).

Projection Notes
Stereographic This is the default projection for most charts. It is conformal (shape-preserving), so constellation shapes are accurate throughout the chart. In very wide fields, it shows significant size distortion toward the edges.
Orthographic Orthographic projection resembles the appearance of a spherical object seen from a great distance (like part of a planet's surface). It can show a maximum of one-half of the sky at a time.
Azimuthal Equal Area (Lambert) As the name suggests, equal areas on the sky map to equal areas on the chart. This can be useful if you're interested in comparing how rich in stars certain parts of the sky are. It can show the entire sky, at the cost of significant distortion near the edges. This is currently the default projection for the Nearby Star Navigator.
Azimuthal Equidistant (Planisphere) In this projection, radial distances from the chart's center are directly proportional to angle from the center in the actual sky. The chart resembles a 'planisphere' star finding tool, except it can be centered on any point, not just one of the poles. Like the Lambert equal-area, it can show the entire sky, though with significant distortion near the edges.
Gnomonic One of the oldest projections, it distorts a bit more at the edges than the others, and always shows less than half the sky. One unique feature: great circle lines -- the shortest distance between two points on the sky -- always project to straight lines on the chart. Meteor observers use this projection to quickly and accurately plot meteor paths, which are great circle paths.

Orthographic and gnomonic projections are unavailable at chart magnifications less than 0.4 (i.e., very wide fields). If you choose a scale smaller than 0.4 and also select one of these projections, you will get a stereographic projection instead.

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