OPTIMA (Optical Pulsar TIMing Analyzer), a high-speed photoncounter was a guest instrument of the 1.3m telescope, provided by the Max Planck Institute for Extraterrestrial Physics (Germany).
OPTIMA, seen on the photo to the right mounted on the telescope, was regularly available at Skinakas Observatory for a period of two to three months each year, until it was decomissioned in 2013.