It has been suggested that Ruskin's depreciation of Canaletto is of work which is either not by Canaletto at all, or is more applicable to Canaletto's very early work or his late work.
Bomford and Finaldi, Venice through Canaletto's Eyes, p.55, summarise a common view of the development of Canaletto 's style:
The most striking feature of Canaletto's technique is the development of his brushwork - the ways in which his handling of paint changed from the flickering touches of the first pictures to the extraordinary assurance, skill and ingenuity of his early maturity to the eventual mechanical repetition of much of his later work.
His earliest work in Venice can be seen in relation to his theatrical training, with abrupt foreshortening, detail subordinated to general effects, and harsh contrasts of light and shade (see No. 1 in Constable, revised Links, Giovanni Antonio Canal 1697-1768).
An example of the work of Canaletto 's maturity would be the effects of the sunlight on the boatmen and roof tiles in The Grand Canal and the Rialto Bridge from the North of 1725 (see Bomford and Finaldi, Venice through Canaletto's Eyes, p 58).
However, Canaletto 's popularity, it is suggested, meant that his style became increasingly mechanical as he struggled to meet the demand for his work:
It manifests itself in a harder treatment of the architecture, and in the introduction of detail by a series of repetitive gestures, such as putting in the lights by a series of dots and dashes; while the fairly large, firmly constructed, well characterised figures which appear in many earlier pictures are replaced by smaller ones, well enough drawn and sufficiently expressive in action, but mainly types resulting from skilfully used recipes, in which dots and dashes again supply the lights. ( Constable, revised Links, Giovanni Antonio Canal 1697-1768, p.117)