More information on photography at La Palma is available in the ``1-m Camera Users Manual'' (La Pama Users' manual V).
The WFC is designed for direct imaging with astrometric accuracy over a wide field at the flat focal plane of the f/8.06 Harmer-Wynne optical system. The camera uses 250 mm 200 mm photographic plates; the unvignetted field is 90 arcmin in diameter and the plate scale is 25.6 arcsec mm. Plate limits of m 20 mag, m 19 mag and m 18 mag are reached with 60 minute exposures on hypersensitised plates under normal atmospheric conditions.
A dummy plate holder is provided with two knife edges at right angles to each other at the centre of the field for focussing purposes. A hinged bracket on the knife-edge assembly carries a mount for a Polaroid 4 inch 5 inch Land film holder, Model 545.