Keck AO allows observers to obtain near-diffraction limited images in the near IR and diffration limited at wavelengths longward of 2.0 microns (K band). With NGS-AO and R-band seeing better than 1 arcsecond, users can expect on-axis Strehl ratios of 50% or better on guide stars with R-band brighter than 12th magnitude. NGS-AO guide stars must be less than 30 arcseconds from the field of interest. NGS-AO outperforms LGS-AO down to guide stars with R = 14th magnitude. LGS-AO guide stars can be as dim as R = 18th magnitude and be 60 arcseconds from the field of interest.

K2AO bench optical path in the early 2000's. The orange beam corresponds to the dual star module, no longer available. The PyWFS is currently located between the calibration unit and NIRC2.	Picture of K2AO bench with the side panels open, with the NIRSPAO plate without its optics on the foreground.