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Rangefinder
Magazine First Exposure: by Ken Storch In the quest for excellence in digital photography, photographers face an extensive array of options at each step of the digital process. Early on in the scheme of digital things comes the choice of camera file format, with some cameras offering a RAW format. In RAW format, the camera only applies a minimal amount of processing to the actual data coming off the chip. These files contain metadata that makes note of, but doesn’t actually apply, the camera settings or subsequent adjustments. This option gives far greater editing capabilities and leaves camera setting choices open to the photographer for later re-editing. The resulting RAW files can be viewed and opened only with certain software. The camera manufacturers provide such software—sometimes as an inclusion with the camera, sometimes as an expensive optional purchase. Photoshop CS, the latest version of the preeminent image editing software, includes Adobe Camera RAW (dubbed ACR2 by many pros). Originally sold as a stand-alone plug-in for $99, having ACR2 included with Photoshop CS gives digicam shooters a cost-saving option. They can use the CS version rather than purchasing a similar application from the original camera manufacturer. Adobe Camera RAW Plug-in Dialog Many of the tools and settings in this dialog will already be familiar to Photoshop users. These should need little explanation since they work like their counterparts in other areas of Photoshop. Keep in mind you probably won’t need all of the settings discussed. Also, combinations of settings can be saved for future use, simplifying later operations. The Tools There’s a checkbox to toggle your adjusted preview on and off, an RGB values readout for measuring a point under your cursor and image rotation icons (to rotate the image, in either direction, in 90° increments). Using rotation only applies changes to the preview. When the file is opened into Photoshop, it will be rotated as part of the Camera RAW processing. Since Photoshop also saves these settings, as explained below, subsequent previewing of the file in the File Browser will also show the rotation. Note that there are no scroll bars in zoomed views, and keys such as “Home” and “End” don’t work within this plug-in, which adds to slow navigation processing on some systems Image Attributes Basic & Advanced Modes Histogram Next down, below the histogram is a Settings space with a drop-down menu. For the moment, leave this option on “Camera Default.” This menu will become more useful once we’ve gone through the process of adjusting an image.
First is the White Balance, with multiple options. “As shot” uses the camera’s settings—unless the plug-in doesn’t recognize these and defaults to “Auto” (allowing for unsupported cameras). In “Auto” the plug-in makes decisions based on the file’s data. The other possibilities, “Daylight,” “Cloudy,” “Shade,” “Tungsten,” “Fluorescent,” and “Flash” do a reasonable job of correcting for these generic lighting situations. The final “Custom” setting is the result from any fine-tuning of the previous settings, along with the “Temperature” and “Tint” sliders. The “Temperature” setting further adjusts the yellow/blue line, and “Tint” modifies the green/magenta relationship. “Exposure” allows us, somewhat, to rethink exposure, with measurements calibrated in stops (i.e. +1.25 is like opening the aperture). Try holding ALT while using the slider, revealing any clipped highlight values. Then back off the slider a bit, to retain these details, while setting the white point. At this point you should be zoomed in at, say, 100 percent to see small details. “Shadows” operates like “Exposure,” and places the black point in the file. Many pros use the following settings at default, preferring to apply such changes later on in editing. “Brightness” shifts the midpoint, and compresses tones on one side, while expanding those on the other. Shifting the slider to the right lightens the image by compressing the highlights and expanding the shadows, while leaving the white and black points as set in “Exposure” and “Shadows.” “Contrast” shifts midtone values, increasing/decreasing the contrast in this range without moving the white and black points. “Saturation” works on the color saturation similar to the slider of the same name under Hue/Saturation. Again, many pros (myself included) prefer to do all sharpening with Photoshop’s more refined tools. “Luminance Smoothing” attempts to minimize grayscale noise, where an area shows pixels varied in brightness (especially in shadows), making the image appear grainy. “Color Noise Reduction” attempts to do a similar correction on color artifacts, where there are random-colored pixels, such as odd colors in a clear blue sky. Lens Tab
As you shift the composition, and the white light moves away from the central axis of the lens, there is a likelihood that color fringing will increase. One side of the light will have, perhaps, a red edge, and the other, in this example, will show a cyan edge. This effect gets worse the further you move from the center, reaching maximum fringing in the corners of the frame. It is most noticeable where there is a distinct, sharp detail of a light against dark, or dark against light, subject in the corner. Zoom in on the detail in one corner of your image, and move the slider along the “Chromatic Aberration R/C” line to correct for the red/cyan fringing, or along the “Chromatic Aberration B/Y” line for blue/yellow fringing. This is a subtle, yet real problem that we can now address. The “Vignetting Amount” slider adjusts the slight darkening in the corners due to lens light falloff. Many lenses designed specifically for digital cameras exhibit noticeable vignetting. This effect seems to happen with incorporated (non-removable) lenses on digicams, as well as lenses made for use on digital SLRs. Lenses made for film, when used on digital cameras with smaller chips (those with a “lens factor”) don’t show this effect as much, in my experience.
Settings and Preferences Below the Histogram, on the right side, is one of those little Photoshop sideways triangles indicating yet another drop-down menu. This option directs where Photoshop will store your RAW file settings. They’re stored by default in a Camera Raw database file, usually located in the user’s Application Data folder. You can change this setting to have Photoshop store .xmp files (a kind of extra file data) in the same folder as the images, which makes long-term archiving a little easier.
There is also a preference for applying any sharpening to preview images only or to all images. I recommend setting this to “Preview images only,” and doing any subsequent sharpening only as needed. Then, when you go to “Save Settings,” you can save all of the settings you’ve adjusted for the current file. Or you could just choose “Save Settings Subset” to save options such as the White Balance, Adjustments, Details, etc.
I recommend naming the settings with a descriptive name for future recognition. Once saved, the name you chose will appear in the “Settings” drop down. (On my systems, only the first 31 characters of the name are visible here.) Camera RAW files allow us to extract more information from the camera, with more editing options while retaining the original data. Adobe Camera RAW 2 now lets us do this within Photoshop CS. There’s a cost in processing time that is a problem for some users. My preview updates are often slow, for example, and there is a slight sense that the plug-in isn’t quite fully developed. Minor quirks aside, this is an important tool for digital camera users. Ultimately, all photographic color choices are subjective choices. Attempts to reduce the entire visual world into the red, green and blue primaries of contemporary photography can only go so far before personal decisions come into play.
Many of us hope that, in future versions, Adobe will include these settings in the main body of Photoshop for use with JPEGs and other file formats. Ken Storch is a digital and traditional artist, educator, photographer, and writer, currently dwelling in an dark Arizona cave, with cameras, computers, coffee, crickets and his cutie. Visit his web site at www.
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Adjust Tab
Detail Tab
occur to some degree.
Now, we have recourse in the Lens tab. The first two sliders correct a type of Chromatic Aberration, which is the lens’s inability to focus all colors in the same place on the chip or film plane. Think of a pure white light bulb, at a distance from your camera, directly in the center of the image. In a perfect world, it would cover just so many pixels, or film grains, with all the colors of the spectrum on top of each other. 
Calibrate Tab
