Her students have been busily taking pictures during the week, and all arrive with a film for processing or some negatives to be printed. As the processing (turning the exposed film into negatives) has to be done "blind" with your hands and arms inside a big, black, light-safe, the knack is to become adept at feeling your way through the fiddly procedure of loading the film on to a spiral in the developing tank.
The darkroom next door, where the processed negatives are printed, is a strange, other-worldly place, bathed in a dim orange glow and lined with shelves of mysterious chemicals, which have to be diluted for use in the various developing and fixing trays. There's no mistaking the students' excitement and curiosity as the blank paper they're swishing about in liquid begins to reveal a black and white image. It's much more fun - and cheaper - than collecting your snaps from the chemist.
Back in the classroom, a selection of Sunday supplement pictures are used to illustrate depth of field, or how the combination of aperture and shutter speed determines sharpness and blur.
Ideally, students need an SLR (single lens reflex) camera, but compact cameras are allowed as students can practise settings on other people's SLRs and learn how their automatic camera makes decisions.
One student is a journalist adding another string to his bow, another is a nanny who has just bought herself a "proper" camera, a third is an art student for whom photography is a complementary art form.
The photography course (evening class from September 10) runs at South Thames College, Wandsworth High Street, London SW18 2PP. Tel: 0181 918 7046.