Early photographers were adept at using natural lighting to idealise the sitter. Manuals of good practice were full of advice on adapting the lighting to soften wrinkles and wreathe blemishes in shadow.
For ladies of a certain age, who often give the photographer a deal of trouble, it is advisable to employ a very soft light falling in front, which softens the wrinkles and protuberances of the face, and obliterates the disagreeable shadows formed by those parts.
(Petsch and Vogel, 2 June 1865, p.257)
Images 37 and 38 demonstrate how the appearance of the sitters could be affected by the use of lighting. The woman in Image 37 displays some lines and furrows, while the smooth face of the woman in Image 38 shows evidence of retouching on the shadowed side.