Title: TTF: a flexible approach to narrowband imaging

Abstract: The Taurus Tunable Filter (TTF) is a tunable narrowband interference filter covering wavelengths from 6300 A to the sensitivity drop-off of conventional CCDs (9600 A), although a blue `arm' (3700-6500 A) is to be added by the end of 1997. The TTF offers monochromatic imaging at the cassegrain foci of both the Anglo-Australian and William Herschel Telescopes, with an adjustable passband of between 6 and 60 A. In addition, frequency switching with the TTF can be synchronized to movement of charge (charge shuffling) on the CCD which has many important applications in astrophysics. Here we review different modes of TTF. We maintain a web site at this http URL describing all aspects of TTF and its operation. In addition to general use, the instrument is available in AAT service time. Details can be found at this http URL