Houdini 9 mm 86° Coma-Correcting Eyepiece

Houdini Eyepiece Performance

The following graph illustrates the performance of the Houdini eyepieces in a F/4 Newtonian telescope. Spot diagrams  with 3,000 rays are shown at the center, halfway, and near the edge of the field.

The spots have been strongly magnified to show them clearly. In the center of the field a spot diagram smaller than 2' is almost perfect, at the edge a spot diagram smaller than 10' is considered excellent. The top left shows 2' and 5' circles.

There is no trace of coma left in the Houdini spot diagrams. Some spherical aberration and some lateral color remain, which shows on very bright objects, such as a magnitude 1 star or Jupiter, at the edge of the field. This is not visible at all in a typical deep sky field that does not contain magnitude 1 stars. Such a field will appear essentially sharp from edge to edge.