Table 2. Afocal relay specifications.

Specification	Value
Aperture stop diameter	2.9 mm at the eye
Full field of view	≥ 30° of visual angle
Afocal magnification	2.6
Spectral bandwidth	455-625 nm (fixation) and 920-960 nm (imaging)
Eye relief	≥ 90 mm
Ocular focusing method	Afocal zoom relay – one moving group
Surface types	Refractive & spherical
Overall size	< 80 x 7.6 x 7.6 cm
Performance of all field angles & wavelengths	< λ/14 RMS wavefront at 0 D < λ/10 RMS wavefront from +10 to −20 D
Ocular aberration correction	LCA: 1.09 D (455-625 nm) & 0.02 D (920-960 nm) Spherical aberration: 0.138um Zernike over a 5.7 mm pupil