Recording and archiving stained glass

Many places of worship house magnificent treasures of art that are seen by only a few.  People can be put off the nature of the building, or in quite a number of cases, there is simply no public access.  When able to see such artwork, the lighting of the windows will not always be optimal for satisfactory viewing.  Thus stunning windows go largely unnoticed and this art form is rarely appreciated.  I have been trying to make such artwork more readily available to the public by photographing the windows, but the photography of stained glass windows is beset with difficulties:

• Light levels within and outside the building are rarely, if ever favourable, with insufficient direct light, or constant partial shadow.
• The height and size of the windows typically results in perspective distortion when photographing with standard lenses.
• Stained glass windows present a dynamic range, beyond the capabilities of the best cameras: is exposure bracketing then painstaking reassembly of the window the best solution?
• The removal of the strengthening bars requires demanding image editing with manual interpolation of the four or five ‘missing’ 1cm strips of window.  Are there better techniques for such work?
• With the image complete, how best to present a reproduction of a window that might be 4-6m tall and backlit by natural light?

I am inclined to think that removing the main subject of a windows from its context will make it more readily appreciated by the viewer (removing dedications and decorations) – certainly this will provide a more manageable aspect ratio.  However, this does then preclude the image from being quite so useful as a historical reference or for insurance archive purposes.  Thus it would seem wasteful not to archive the entirety of a window and then crop out the ‘flesh’ for more public consumption.  This does raise an important consideration: what is the current thinking on most effective archiving of data files when the images are required as an insurance backup against catastrophic damage?

Exposure bracketing was used to produce six images of the stained glass window, to provide a full range of exposures from heavily underexposed (to reveal detail in the darker areas) through to heavily overexposed (revealing detail in the lighter areas).  From those six images, a seventh image was constructed, single segment of glass at a time, having first selected the most appropriate piece from the original images.  Considerable time was then spent remove the unsightly, horizontal metal support bars before some cosmetic ‘cleaning’ of the seventh image.  The three images below illustrate the process.