Raw Processing Options; A Sampler For Every Camera & Budget
Shooting JPEG images is similar to shooting color negative film and handing the roll to a photo lab for processing and printing. The results--overall--are generally good. But someone else is making decisions about sharpness, white balance, saturation, and other vital parameters that determine how the final image looks. In the case of digital cameras, a group of engineers decide how much sharpening to apply to an image file, which colors to favor, and how to handle every other variable. These decisions are programmed into an ASIC (Application Specific Integrated Circuit) that processes the digital signals before they're written to the memory card. If you shoot the same scene with two different brands of digital cameras and carefully examine the results you'll see that they're quite different. That's because two different groups of engineers decided how the processed images should look.
If you want to make these decisions yourself, shoot raw. Think of it as shooting
a color slide, as opposed to a print made from the color negative example detailed
earlier. When you shoot a color transparency, the end result is the actual exposed
film itself, devoid of any manipulation. A raw image file is subjected to only
minimal in camera processing, so important variables like white balance, saturation,
sharpness, and so forth are left up to you.
Raw has some baggage. Cameras from different manufacturers store image files in different formats that are incompatible. This is completely understandable. For competitive reasons, each manufacturer strives to create the best image possible. If something is better, by definition it must be different. There are physical reasons, too. A 14-bit A/D converter produces image data that's quite different compared to what's produced by a 12-bit chip. As a result, raw files require special browsers to be viewed and special software for conversion to JPEG or TIFF.
Camera manufacturers are, by and large, deficient where writing software is
concerned. And for competitive reasons, they want to keep their processing algorithms
and the details of their code library secret. Some have even been accused of
encrypting all or parts of the image data. Although the situation improves with
every passing season, software development has never been considered a core
competency for most camera hardware manufacturers.
To make matters worse, slight changes in proprietary file formats--when a new and improved D-SLR model is added to a manufacturer's line-up, for instance--can derail cross-platform compatibility. And major changes in PC operating systems can render imaging software obsolete. That makes long-term storage of images in a proprietary file format a very dangerous proposition. Plus, there is always the risk that a camera manufacturer will go out of business or lose interest in the camera market and abandon the category--like Minolta did--or arbitrarily decide to stop supporting legacy products.
Fortunately, there are many ways to overcome the file format perils. Direct raw support in Adobe's Photoshop CS is the most obvious solution. However, not everyone needs, wants, or can afford Creative Suite. Fret not--there are many solid alternatives and some are even free.
Adobe (www.adobe.com) addresses this issue with the Digital Negative (DNG), an archival format for raw files that is built on a publicly disclosed structural design. The DNG file format is the common denominator that allows images from different brands of cameras to be used across various platforms without a glitch. And because many software and hardware manufacturers--including Hasselblad, Leica, Pentax, Ricoh, and Samsung on the camera side and Apple, ArcSoft, Canto, Corel, DxO, Extensis, and IrfanView on the software side--have embraced it as a standard, photographers are virtually guaranteed long-term archival safety.
Adobe offers a free DNG Converter, a stand-alone application, for both Windows and Macintosh users. It conveniently translates raw files from practically any digital camera into a universally compatible DNG file. As one might expect, the Photoshop Camera Raw plug-in (2.3 or higher) supports raw files in the DNG format.
Lightroom, Adobe's much ballyhooed image viewer/workflow application, supports over 150 raw formats and delivers one of the slickest GUIs around. Lightroom utilizes nondestructive editing, which means that the adjustments you make to your images will not corrupt the original data, regardless of which file format you're working with. Batch processing allows you to correct for color cast and white balance point, make exposure adjustments, tweak tonal curves, and compensate for lens distortion--to several images simultaneously. Once you've determined the right combination of corrections, all can be applied sequentially to the selected images--a real timesaver when processing a group of image files that were captured under the same lighting conditions.
Apple's epochal Aperture is arguably the first imaging workflow software
to seemingly get inside the professional photographer's head to deliver
features and functions that pros require. In their own words, Apple (www.apple.com)
goes one step beyond to enable creation of versions of master images to preview,
crop, color correct, sharpen, and subject to other modifications. There's
practically no limit to what Mac users can do with Aperture.
If you shoot raw format with certain Canon or Nikon cameras and use Windows XP you should know about Microsoft RAW Image Thumbnailer and Viewer. It's a "Powertoy" that can be downloaded free of charge from Microsoft's website (www.microsoft.com). It's not part of Windows and is not supported by Microsoft (don't call their Tech Support) but if you follow the directions it's highly unlikely that you'll have any problems.
It's actually two separate components. The first allows you to view raw images in Windows Explorer the same way you can view JPEG images. It also adds Preview, Edit, and Print commands to the context menu when you right-click a raw image. The second is a viewer application that is very similar to Windows Picture and Fax Viewer. It provides previews, printing, and slide shows for raw image files.
One of the most useful features of this software is its ability to display metadata when you hover the mouse pointer over an image. You can read the image dimensions, camera model, aperture, shutter speed, and other parameters quickly and easily. That information makes it much easier to find a particular image.
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