92% Strehl Sloan r’ Image

The below image is our 92% Strehl Sloan r’ band image with our triplet ADC and dichroic beamsplitter in the beam.  The slight elongation of the PSF and the asymetric contrast of the fringes are due to the “zenith spike” effect of the ADC.  This effect is predicted by our models and will not manifest itself on-sky when the atmosphere will counteract the residual chromatism of the ADC.

Spot diagram showing the broadband chromatic "zenith spike" effect of the ADC in the lab.