It is a popular notion that RAW files offer the best
possible image quality. However, some in-camera
processing can produce results that are
unobtainable with RAW. The real advantage of
recording in RAW is that it provides the largest
reserve of data for image manipulation.
Extracting color
Before opting for a RAW workflow, it is sobering to
consider the JPEG alternative. All sensors produce
raw image data. When a camera saves the image as
a JPEG (or, rarely, as a TIFF—see p. 176) it first extracts
the full color information from the sensor, then
applies adjustments regarding contrast, color
saturation, sharpness, and so on. These parameters
have been designed by experts in color science and
sensor technology. If you think you can do better
than them, by all means work with RAW files. But
a common complaint is of RAW processing
producing images inferior to camera JPEGs.
Advantages of RAW
Nonetheless, while working with RAW requires a
great deal more time and effort than with JPEG files,
the rewards are there for those who truly require
the quality—because they need to enlarge images to
their limits, or publish them in top-class print media.
RAW processing preserves the maximum amount
of original image data—particularly in shadow and
highlights—which helps to ensure the highest
possible image quality from each file. It offers you
maximum flexibility with image brightness, white
balance, and color space. However, remember that
if you make prints smaller than the maximum
recommended your files, many of the advantages
of RAW processing will be lost in the print.
Batch conversion
The job of a RAW file converter, then, is to apply all
the processing that the camera would normally do
to deliver vibrant, sharp, and well-exposed images.
All RAW conversion software allows you to save
settings then apply the same setting to entire folders
full of images: this is known as batch processing,
and clearly it can save a great deal of manual
effort and time-consuming supervision. However
processing large numbers of images will take
some time, even on fast computers, because of
the large files involved.
You can go further than any camera by tailoring
the presets to different conditions. With landscapes,
for example, you may aim for higher sharpness and
saturation than you would when making portraits.
You can create presets to suit different subjects and
styles: high saturation, contrast, and sharpness for
landscapes and urban views; low vibrance for
documentary photography; sepia tone and soft
contrast for portraits, and so on. This workflow is
flexible yet it saves a great deal of time.
RAW styles
Not all RAW conversion software is created equal.
Indeed, not only do the interface design, ease and
speed of operation, support for your camera, and
cost vary, but each application applies subtly
different philosophies to image processing; for
example, noise reduction being preferred over detail
preservation. Nonetheless, where output has been
expertly processed, it is very hard to identify any
significant differences. With modern solutions, it is
safe to select an application based on what you find
easiest to use, but first ensure that your camera’s
specific RAW format is supported.
Adobe Digital Negative (DNG) is an attempt to
bring order to the proliferation of RAW formats
by creating a common “wrapper,” or structure,
for the data. Introduced in 2004, it is based on a
standard format known as TIFF-EP. It is designed
to accommodate metadata (such as MakerNotes
for the camera) in order to allow for any DNG-
compliant RAW converter to work on raw data
irrespective of its source. As of 2010, DNG was
supported by over 300 non-Adobe products and
software—but is by no means universally
adopted, particularly among the larger camera
manufacturers. Suffixes for files are .dng or .DNG.

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