Hacking stereoscopic vision: the nineteenthcentury culture of critical inquiry in stereoscope use

摘要

While recent scholarship has emphasised thenarratives of immersive realism that surroundedthe parlour stereoscope, my aim in this paper is tobetter understand the counter-currents of nineteenthcentury stereoscopic culture – the artefacts, practicesand discourses that powerfully undermined realistassumptions about spatial perception and the“truth” of stereoscopic representation. Wheatstone’soriginal stereoscopes were designed to “hack” spatialperception and subject each of its component principlesto artificial manipulation. What Wheatstone uncoveredwere glaring anomalies in the prevailing theories ofveridical sight, which had relied upon the principleof binocular convergence (understood as a precisetrigonometric measure of depth). Following a populartradition of critical inquiry known as “rational recreation,”amateurs too used their stereoscopes to reflect on theperplexities of binocular spatial perception. Analyticline drawings highlighted the inexplicable binocularsuture of strikingly disparate images. Stereoviewswith their images transposed revealed the capacity ofthe mind to constitute volumetric objects irrespectiveof binocular cues. Hyper-stereo images (taken froma wide separation and therefore at an increasedangle of binocular convergence) sparked debate andperceptual uncertainty as to whether their 3D effects,or indeed all stereoviews, were distorted – elongatedalong the z axis and/or miniaturised. Realists, includingsome astronomers hoping to use hyper-stereophotographs as visual evidence of the shape of themoon’s surface, sought unsuccessfully to solve theproblem of elongation by ensuring that the angles atwhich stereo photographs were taken were reproducedin the angles at which the eyes viewed them in thestereoscope. Astronomers were forced to quietlyabandon the stereoscope as a reliable witness ofspatial form. Others, artists in particular, revelled in theanti-realist implications of a spatial imagination whichconstructed the perceptual world in a sometimescapricious fashion.