Friday, May 25, 2007
B&W Comes Of Age
There has been a paradigm shift in what photographers can do with black-and-white imagery. Digital tools and capabilities have opened the medium to new possibilities.
Analog Or Digital
One of the major paradigm shifts presented by digital imaging is that you can start and finish with any media, analog or digital. When it comes to input, you have two choices: analog film or digital capture. Within each of these choices you have two more choices: black-and-white or color. Let's go through the various ins and outs of each choice. Before we do, let me give you the bottom line. For maximum quality and control, choose color digital capture.
Digital Capture. Though it requires an initial up-front investment (sensor and software) rather than an ongoing one (film and processing), high-end digital-capture image quality outperforms film in every category—higher resolving power, lower signal-to-noise ratios, greater latitude, etc. For archiving, duplicates may be created with no loss in quality. (Save unprocessed files in DNG and processed files in TIFF.) Digital capture requires no scanning, but RAW conversion is typically necessary. As they can be converted and reconverted, adjusted and readjusted, and then output to any media, analog or digital, digital images offer superior flexibility.
By default, digital cameras capture in color. You can program some digital cameras to create black-and-white files. Software is then used to convert the resulting file on the fly at the point of capture. You can make this conversion more precisely after capture.
Scan Film. Of course, you can use black-and-white or color film. (While it's best to return to the original source, if film has been lost or damaged, you can even start with a print.) This allows easy, economic access to the traditional silver darkroom. To take advantage of the digital darkroom's superior tonal control, you first need to scan the film. Scan in 16-bit, at high resolution (6000 ppi for 35mm originals and 4000 ppi for larger originals) into a wide-gamut editing space (for color). Turn off any software corrections, including sharpening.
Scanning transparencies is straightforward. When scanning color negatives, use the Lookup Table to remove the warm-hued base, which is challenging to do after scanning. When scanning black-and-white negatives, avoid possible clipping of shadow or highlight details by not using scanner Lookup Tables; instead, scan black-and-white negative film in grayscale as a transparency, and after scanning, invert it while editing the resulting file.
Negative film gains its increased dynamic range by virtue of its low contrast. When you increase the contrast of images to return them to a normal range of contrast, noise becomes more pronounced. When you use negative film, you may gain an extra two to three stops of latitude, but you also gain noise roughly equivalent to an additional ISO rating.