Some of the first astronomical CCD images were obtained at Palomar 200-inch in 1976, by J. Westphal, J. E. Gunn, and collaborators, using an experimental TI 400x400 CCD (a prototype for the HST TI 800x800 CCDs widely used later), where only a 256x256 section was actually usable.
M87 core: the original, with the azimuthally averaged galaxy light subtracted, and the same image with a higher contrast.
Images of a cluster of galaxies at z ~ 0.6, reaching to R ~ 25.5 mag
(the object marked with the arrow has R ~ 24.5 mag). The image on the right
is a high-contrast version of the image on the left. Prior to these
observations, the deepest images obtained using SIT Vidicons reached
R ~ 23.5 mag or so.
