The magazine of the Melbourne PC User Group Camera RAW - for the bookshelf Major Keary

 
Camera raw and raw are terms that crop up particularly in advanced texts on image editing; they mean the same thing and refer to the 'base' file created by a digital camera.

When a digital camera's button is pressed to take the picture a flow of information passes through the lens to the imaging array's light sensitive cells, generating electrical impulses that are translated by a processor into raw image data. In most cameras the raw data is converted to a deliverable graphic image format and then discarded. Scanners work in the same way: data is collected in a vendor-specific file format that is discarded after the image has been saved to a user-nominated format.

Each camera manufacturer has its own, proprietary method of writing raw data that typically contains three elements: EXIF metadata, which includes camera model, exposure details (shutter speed and aperture), lens focal length, ISO setting, and filename; image data, which can be saved and later edited using software; and raw data, which comes from the sensors. A camera raw image provides much more information to play with than working with a JPEG or TIFF file, but saving raw images requires a lot of memory, which is one reason why not all digital cameras save RAW data. The other reason is that not all users want — or need — to be bothered with it.
 
Photoshop RAW

For those who have equipment that enables images to be saved as RAW files, and who want the best possible end result, RAW is the digital equivalent of a film negative: it contains "the unadulterated data that comes from a digital camera" [Mikkel Aaland: Photoshop CS2 RAW]. In traditional photography the negative contains — to use computer parlance — source information that can be used in a multitude of ways to produce infinitely different results; a 35 mm Kodachrome transparency contains the equivalent of some 20 Megabytes of digital data.

Adobe Photoshop CS2 comes with three modules: Photoshop, Bridge, and Camera RAW. Bridge is described as a central organiser for images, the command centre for Adobe's Creative Suite (the CS that has become a suffix for a number of Adobe products), and a gateway to either Camera RAW or Photoshop. Bridge can also be used to launch Photoshop's Image Processor for quick conversions to deliverable file formats, such as JPEG.

The primary focus of Mikkel Aaland's book is on using Camera RAW, but it also shows how to use Bridge and Photoshop with RAW files. Camera RAW is able to read the proprietary formats used by different camera manufacturers. Adobe is continually revising Camera RAW to include new or variant formats and makes updates of the program freely available. Adobe has also developed a format, DNG (digital negative), that enables users to convert proprietary-format RAW files to a standard for saving and archiving raw images; a converter is incorporated in Camera RAW, but Adobe also distributes a free standalone version.

The book is not about photographic technique. It is about taking a RAW image and processing it to achieve the best desired result. It shows how to use Bridge to move RAW files between Camera RAW and Photoshop, how to use the facilities of Camera RAW to edit an image, and how to polish, so to speak, the result in Photoshop. The use of RAW images is highly technical territory, but the author presents it in exceptionally clear language. An example is the chapter on Advanced Tonal Control, which includes a discussion on how dynamic range can be extended using a new addition to Photoshop, Merge to High Dynamic Range (HDR), a tool that enables the user "to blend or merge three or more files taken of the same scene with different exposures [to] create a new file capable of storing an almost infinite number of tonal values".

The book's large (204 x 254 mm) format lends itself to the attractive, and effective, layout that works on two-page spreads. Text is confined to a column on the outside edge of each facing page and the rest of the space given to images — many of them screen captures — that accompany the text. Illustrations are not simply aren't-I-clever reproductions of before-and-after pictures, but include useful information about the tools used and the settings. In some instances the text is a concise commentary on the information delivered by the screen shots. The writing style is conversational and the presentation what one might call 'informal tutorial' that varies between step-by-step instructions and explanations.

If you are at all remotely interested in RAW and its potential, read this book. If you have a digital camera that can capture in RAW format, and want to know how to use the facility, read this book. If you are looking for ways to produce 'fine art' images it is an essential resource. If you are content with the JPEG images that your current equipment delivers, then give it a miss.

Photography is a field where non-professionals can achieve the same level of excellence as professionals. Anyone who wants to take digital photography to its limits, whether for personal satisfaction or in a professional capacity, should have this book. Highly recommended as a library acquisition.
 

RAW in Elements 3

The RAW converter is included in Photoshop Elements 3 and later versions. It is discussed in Barbara Brundage's Photoshop Elements 3: The Missing Manual; the section (ten pages) is brief, but sufficient, to explain the basics of using Camera RAW in Elements.

Elements 3 is a significant upgrade, including a number of new features that were previously available in only Photoshop CS. This title is an excellent manual for users at all levels, making good use of full-colour images to support the clearly written text. It covers all features, the technical detail is well presented, and information is easy to find.

Reprinted from the June 2006 issue of PC Update, the magazine of Melbourne PC User Group, Australia

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