Digital Photography and Computer Aided ImagingPosted on: Jul 21, 2011
One can debate the virtues of film versus digital and there are advantages to each medium. With film, the object was always to create the perfect image because trying to improve it after the shutter had closed was difficult if not impossible. With digital cameras, the object seems to be to collect as much raw data as you can so that you can reassemble the image in post production. The perfect image we all lust for is something that happens much later.
Recently I shot an assignment for Swatt|Miers Architects that called for some major computer doctoring to create images that could not have been done any other way. The photo-merge concept has been around for a long time and subsequent software improvements have made it much more robust. Adobe has incorporated a fairly good photo-merge tool in later versions of PhotoShop. Today, even point and shoot cameras come with some rudimentary merge software. The key in the process is to have the camera rotate on the nodal point of the lens and lap the images so that the merge tool can “cut and paste” from each image to make the composite. The image you see above was composited from four individual shots and stitched together by the P.S. merge tool. Short of bringing a man-lift on site and parking it precariously on a significant slope, there was no way to get this view of the building. What is most remarkable is the rectilinear correction that the software created.
HDR or High Dynamic Range imagery has also been around for a long time. In the film era, the likes of Ansel Adams and yours truly mixed Pyrogallic acid developer to suppress highlights and extend tonal range in black and white film. No, I am not as old as Adams, but I did mix my own chemicals back in the days of black and white and used the same formulas he used to control highlight density in my negatives. Today that same effect is achieved in digital photography by creating multiple exposures of the same shot and then using sophisticated software to blend the lights and the darks into a pleasing composite image. In the image above was created using NIK tools HDR Efex Pro and PhotoShop. There are a variety of techniques one can use to get to the same place including hauling a ton of strobe lighting to the site and lighting the scene with several thousand watts of light. But that does take time, an assistant or two and serious effort. HDR doesn’t work all the time and cannot get you out of a black pit, but with a deft hand and a favorable environment, it can produce some pleasing results and certainly speed along a day’s shoot.
A few years back when we were still shooting film, doing eight shots in a day was about the limit. In today’s digital world we are closer to twenty. The digital revolution has lightened photographer’s equipment cases and moved much creativity from the camera to the computer.