John Ruskin: Artist and Observer at first appears to be an unassuming display of watercolours, sketches and photos, appealing only to enthusiasts for either the media or the natural or architectural subjects that form its visual content. Yet by the time this presentation of Ruskin’s works has been viewed in its entirety, the revered art critic has been knocked off his pedestal.

Beyond the Portrait Gallery’s confusing navigational sequence (an uneasy combination of chronological and thematic sections), the material itself raises perplexing questions about the nature of observing and recording. Ruskin’s skill as a delineator of nature is evident, while the architectural studies reveal his passion for the topics of his critical writings.
Yet sporadically present in the works are a number of studies after paintings he admired. Here, Ruskin’s observational hand strips the originals of their vivacity, rendering the evocative clouds of Turner to diagrammatic wisps.

His own observations, like the absorbing ‘Vineyard Walk, Lucca,’ reveal that Ruskin’s was not just a scientific hand. Yet among an oeuvre that largely functioned as a means of observing the world, his lifeless recreations of artistic works cast a dull shadow over the rest of the exhibition, threatening to eclipse his more emotive, subtler impressions.

Scottish National Portrait Gallery, 624 6200, until Sun 28 Sep, £8 (£6).