Observations

All our observations were short direct exposures with CCD's. At Lick Observatory we used a TI 500×500 chip and a GEC 575×385, on the 1-m Nickel reflector. The only filter available at Lick was red. At CTIO we used a GEC 575×385, with B, V, and R filters, and an RCA 512×320, with #math163#U, B, V, R, and I filters, on the 1.5-m reflector. In the CTIO observations we tried to concentrate on the shortest practicable wavelengths; but faintness, reddening, and poor short-wavelength sensitivity often kept us from observing in U or even in B. All four cameras had scales of the order of 0.4 arcsec/pixel, and our field sizes were around 3 arcmin.

The CCD images are unfortunately not always suitable, for very poor clusters or for clusters with large cores. Since the latter are easily studied by other means, we augmented our own CCD profiles by collecting from the literature a number of star-count profiles ([#kin68##1###,#pet76##1###,#har84##1###,#ort85##1###]), as well as photoelectric profiles ([#kin66##1###]) and electronographic profiles ([#kro84##1###]). In a few cases we judged normality by eye estimates on one of the Sky Surveys.