Today is the birthdate, in 1862, of Sebastian Finsterwalder the “father of glacier photogrammetry”. Let me share with you some thoughts that this fact provokes.
After its invention, photography was regarded as commentator Lady Elizabeth Eastlake describes in the London Quarterly Review in 1857;
“[photography] is the sworn witnesss of everything presented to her view. What are her unerring records in the service of mechanics engineering, geology, and natural history, but facts of the most sterling and stubborn kind?” [I’d ask you to remember that Eastlake said “unerring records in the service of …geology, and natural history”]
Fifty years later, George Bernard Shaw, writing in Camera Work of 1906 agreed:
“Photography is so truthful –its subjects so obviously realities and not idle fancies–that dignity is imposed on it as effectually as it is on church congregation.”
That ‘the camera can lie’ comes to public consciousness by the 1920s:
“The trick photograph shows that the camera can lie, and lie most artistically and Ananiasly [Ananias was the prophet killed by God for lying]. A lady holding her own head upon a platter is nothing difficult to the trick artist. To have a picture of yourself playing cards with yourself is simplicity itself”, reads The Camera: A Practical Magazine for Photographers in its 1920 edition.
Susan Sontag seems to echo Eastlake’s sentiments:
“Photographs furnish evidence. Something we hear about, but doubt, seems proven when we’re shown a photograph of it.” (Susan Sontag , On Photography, ISBN: 0385267061 , Page: 5).
However, she finds she must qualify this with equivocations and caveats that fill her book; “What is true of photographs is true of the world seen photographically”, and “Although there is a sense which the camera does indeed capture reality, not just interpret it, photographs are as much an interpretation of the world as painting and drawings are.”
Widely read, in fact compulsory reading for most students of photography, Susan Sontag’s opinions have changed our attitudes to the medium. Her ideas about its truthfulness, and her warnings about its seditiousness have been transmitted beyond those numbers who have read her. So doubts about the medium’s veracity do not originate in the digital age. Certainly, authorship and consumption of images has multiplied beyond a 1977 imagination (when On Photography was first released) when photography was chemical. Yes, the means and motives for altering and manipulating photographs have become more available, more easy, more compelling with Photoshop and Instagram. Awareness that appearances can be both fact and illusion are embedded in the medium itself, apparent to anyone who uses a camera, which now includes almost everyone almost every day so that we no longer need Sontag to interpret for us the relation of photography with appearance this way: “There is the surface. Now think – or rather feel, intuit – what is beyond it, what the reality must be like if it looks that way. Photographs, which cannot themselves explain anything, are inexhaustible invitations to deduction, speculation, and fantasy…”. To put it simply; no photograph is a statement and every one is a question.
How might that apply to an outer branch of photography; photogrammetry?
“Photogrammetry – the art of making measurements using images – is the task of determining an object or its dimensions using photographs.” writes Bavarian Sebastian Finsterwalder in his 1906 chapter Photogrammetrie in the Encyklopeidie der Mathematischen Wissenschaften mit Einschluft ihrer Anwendungen. Band VI, Teil1, Geodeisie und Geophysik.
This application of photography can also record complex motion by tracking pathways of designated reference points on any moving object, on its components, and in the immediately adjacent environment. For Finsterwalder, that motion was, literally, glacial; he studied the flow of glaciers in the Bavarian and neighbouring Italian Alps. At the tender age of 24 he received his doctorate for showing that Rudolf Sturm’s analysis of the “homography problem” (1869) can be used to solve the problem of 3D-reconstruction using point matches in two images; which is the mathematical foundation of photogrammetry.
Finsterwalder pioneered geodetic surveys in the high mountains. At the age of 27 years he conducted a first glacier mapping project at Vernagtferner in the Ötztal Alps, Austria. Repeat photographs, some which he had taken from a hot air ballon, some with the novel lightweight, accurate phototheodolite that he had developed for high-mountain applications, later augmented with stereoscopy, were the means by which he could track flow on an irregular object as vast and as poorly accessible as a glacier.
Finsterwalder’s 1923 and 1924 measurements of flow velocity across Ölgruben rock glacier have made it the subject of a notably extended longitudinal study with high value in climate research; repeat surveys of it were undertaken by Wolfgang Pillewizer in 1938, 1939, and 1953 using photogrammetry, and these continue using modern satellite-based positioning techniques, along with a rebirth of terrestrial photogrammetry in high-mountain mapping, which also includes rock glacier monitoring, in the wake of cheap digital consumer cameras and powerful computer software. [see: Viktor Kaufmann (2012) The evolution of rock glacier monitoring using terrestrial photogrammetry: the example of Äußeres Hochebenkar rock glacier (Austria) in Austrian Journal of Earth Sciences Volume 105/2 Vienna]
Finsterwalder’s son Richard went on to advance his father’s mapping project in the Ötztal Alps. These Alps are the location in which ‘Ötzi the Iceman’, was found in 1991; a well-preserved natural mummy of a man who lived about 3,300 BCE, brought to the surface due to the melting of the glacier which entombed him. Richard worked later in the Himalayas, whose glaciers are also retreating, until his death in 1960.
In photogrammetry, ‘the surface’ to which Sontag refers, ‘touched’ only by the lens, yields data – ‘evidence’ – crucial to our understanding of change in our world (and it is the principles of photogrammetry on which Google Earth is built). It is a scientific discipline that stands at the extreme edge of Sontag’s spectrum of ‘deduction–speculation–fantasy’.
Where does it leave photography in relation to truth?