In 1895 Emerson produced Marsh Leaves, the last of his volumes of photographs to be published. Smaller in format than the early works, it is illustrated with sixteen photogravures. For On English Lagoons and Marsh Leaves Emerson did, as he claimed he would do, make all his own photogravure plates, finally freeing himself from commercial engravers.
 
Many of the photographs in this last book demonstrate that he was no longer exclusively concerned with the direct transcribing of perception. Several are taken with a lens of relatively long focal length, resulting in a distant, two-dimensional view quite different from unaided human vision. He was using, to borrow a phrase from Aaron Scharf, ‘the vocabulary and syntax’ of photography. It is possible that, released by his "Renunciation" from the requirement to follow artistic conventions, Emerson at last felt free to discover what photography itself had to offer.
 
It is tempting to see, in Emerson’s last published photographs, the first suggestions that he had begun to adopt an approach and a working practice that were closer to the twentieth century than to the nineteenth, and it is certainly true that he maintained a keen interest in the most recent technology. No photograph he took after the mid-nineties has been identified, however, so as far as posterity is concerned, his career as a photographer ended in 1895.
 
The distinctive characteristics of Emerson's later work have been noted by other writers, notably Ian Jeffrey, in: Emerson Overturned; On English Lagoons and Marsh Leaves in British Photography in the Nineteenth Century (1989) Weaver, Mike (ed.) Cambridge University Press and Mark Durden, in: Peter Henry Emerson, The Limits of Representation in History of Photography, vol. 18 No. 3 (Autumn 1994) pp. 281-4.