Wednesday, 24 April 2013

Rob Freeman's House

If you look at the list of links down at the bottom of this page, you will notice that I have recently added a link to Rob Freeman Building. Rob is a long-time friend of mine from school days, and now lives down in Devon. He runs his own construction company, specialising in conservation and renovation using old-time traditional techniques and materials. As a billboard, demonstrating the kind of work his company does, is his own house (pictured here) which is a combination of the original dormer building and the modern extension, enlarged to accommodate Rob's family.

The first set of photos are from New Year's Eve a few years ago, showing paper lanterns placed around the ornamental pond, situated on the patio in the back garden. The attraction of the scene, to me, was the presence of the reflections in the mirror-calm of the water. The camera that I was using for these shots was a long-in-the-tooth Nikon D100, with non-functioning light meter, and which worked only in manual mode. (I mention this by way of excusing the variation in exposure of the pictures, even though this does not necessarily work to their detriment).

It is true (as noted by some of my photographic friends) that I have something of a preoccupation with reflections. I would say, in my defence, that I am not alone in this. Henri Cartier-Bresson's "Gare St. Lazare", and many of Ansel Adams' landscapes demonstrate some classic examples of reflections within the historical canon of photography. In my case, the fascination lies within the 'image within an image' aspects of the pictures, and the tricks our minds play on us when we 'look' (with our eyes) at a reflection, then 'look again' when we examine the photograph some time later. Suffice to say, given the limitations of the camera record of a scene (particularly one recorded in low light) what I remember of the scene as seen by the naked eye bears little resemblance to the photographic images. This is generally due to the lack of recorded detail in the deep shadow areas, which because of the nature of reflections in water, tends to be within the reflection areas of the picture.

An example of so-called 'diffraction flare', a photographic phenomenon unique to digital cameras
However, that is not the major interest that I have in these images. I had spotted before, but not paid significant attention to, the phenomenon illustrated in the images above. I have encountered (and combatted) flare for most of my photographic life (and will be posting an article on flare in the near future), so I am familiar with it, and its manifestations in the viewfinder. The coloured blobs, clearly seen in all of the images above, and which I had previously assumed to be flare, were not visible in the viewfinder. This indicates that the artefacts (the coloured blobs) cannot be a lens-related occurrence.

The more I thought about it, particularly the fact that all of the blobs feature the three primary colours red, green and blue, the more I came around to considering the reseau, or Bayer filter, that is incorporated into the digital sensor at the heart of a digital camera. (The link below is one of the many places on the Internet that a description of the structure of a digital sensor can be found).

More research has led me to the revelation that the phenomenon is indeed linked to the image sensor (and that it is unique to digital photographs) and is caused by diffraction of high intensity light rays by the pixel structure of the sensor array. This article on Wikipedia mentions it (near the bottom of the page) and even comments on the fact that it is not visible in the viewfinder.

Who says you can't teach old dogs new tricks?

I will conclude with some pictures of the house, taken in daylight last November. Good weather always makes a photograph look more attractive, and being on holiday (which I invariably am when visiting Rob) makes the process of photographing very pleasurable. However, while the physical comfort of having the warmth of the sun on your back makes photography enjoyable, clear blue skies can mean death to a photograph. Even though a photographer may not have the choice (ultimately you photograph under the circumstances that you find on the day) a few clouds can make all the difference to the appearance of a picture. Most of the time, this just means that I will have to go back and try again on another day.

No comments:

Post a Comment