Tag: River Wandle

As a photographer I’ve long been interested in the difference between how we experience the world around us and how the camera records it. Some of those differences are obvious but others less so, and some we are seldom aware of.

The camera records an image produced by its lens which follows strict optical rules which I learnt about long ago in my physics lessons, though real lenses deviate slightly from those ideal and perfect specimens in those science texts.

The camera holds a film or sensor to record that image – and again does so following strict physical (and chemical for film) processes which may fail to record significant features and distort others to produce an essentially flat two-dimensional image. It may not even record colours but if it does they always to some extent arbitrary, as too are the tones.

Those of us who grew up on film are perhaps more aware of this than the digital generations. We had to be aware of the differences in recording of, for example Ilford’s Pan F and Kodak’s Tri-X, and how these were affected by processing and printing, and of the rather unreal but different colour renditions of Kodachrome, Kodacolor, Ektachrome, Agfa, Ferraniacolor and the other colour film films, each with its own qualities. Though perhaps if we ever used Orwo film quality was not the right word for its purplish nature.

Of course there are differences in the way digital cameras record colour, but these are rather smaller, and we can make use of software to make them match more closely or exaggerate the difference. Lightroom and Photoshop can make my Fuji files look very similar in terms of colour rendition to those from Nikon.

But our experience of a scene is very different, combining inputs from all of our senses, and it would be impossible to over-emphasise the subjective aspects. But even just visually it is still very different. While the lens cuts out all but a small rectangle in front of us, our eyes send information to the brain from a much wider field, much of it except from a small central section lacking in sharpness. Most of us have binocular vision, gathering this data from two eyes a short but significant distance apart, enabling us to see in depth. And our view is always dynamic, our eyes moving around, and as we swing our head around or up and down we have the sensation of moving through a static universe. Doing the same with a camera has a very different effect.

A standard lens – around 40 to 50mm on a full frame digital or 35mm film camera gives a similar idea of depth in its flat images to that we normally experience. With longer lens the effect of depth is reduced and by the time we get to really long lenses the images become flat patterns rather than appearing to represent a three dimensional scene. But what interested me more was what happened when the camera tried to represent a much wider angle of view than the standard, when the rectilinear rendering of normal lenses becomes impossible.

On Monday 14th of March I went for a walk with a painter friend who had brought her sketch book to introduce her to an area I thought she might find interesting. And I wanted to further explore some of the different ways of rendering very wide angles of view with digital cameras. I’d brought two Nikons with me, one fitted with a conventional wide-angle zoom which I used mainly at 16mm, close to the limit for such lenses (and I do have a wider lens which demonstrates this) and the other with a 16mm full-frame fisheye which fills the frame with an image which is 180 degrees across the diagonal.

While my friend stopped to make sketches I had time to make a series of images from similar locations. I kept warmer as I was moving around, but she fairly soon got cold, which was a good excuse to visit the pub which appears in some of these pictures, after which I took her back to the station where we had met and went back to take some more pictures on my own.

Back home I uploaded the images. Those from the conventional wide-angle zoom I’ve use as they were taken, with just the normal adjustments in Lightroom. But the fish-eye images I worked on with my panorama stitching software, PtGui, not to join images but to take the raw image data and process it it various different ways to produce cylindrical projections. If the camera was upright when the picture was taken, this will produce straight vertical lines for all upright elements. There are many different approaches to this which produce visually different results, some of which are common in mapping, such as Mercator.

Those I’ve found most useful are the equirectangular, Vedutismo and Transverse Vedutismo projections used in these examples.

More panoramic images from my walk on My London Diary at Wandsworth Panoramas.