Identification and Elimination of Plate Flaws in Copying

Abstract

Since it came into operation in 1973 the UK 1.2m Schmidt Telescope (UKST) has taken nearly 12,000 wide field photographs of the Southern Sky. Many of these plates were taken for a Sky Survey and the precision copies for world-wide distribution, on both film and glass, have been made in Australia, at ESO, and, since 1978 at the Royal Observatory, Edinburgh. In order that the maximum amount of information can be transferred from original plate to final copy with the minimum introduction of flaws or spurious images, meticulously maintained clean rooms are essential for the copying procedure. Unfortunately, even in the best managed darkrooms, problems do occur; this paper will illustrate some of the problems encountered at ROE and, where possible, the solutions found.