Sunday, September 19, 2010

How To Process A RAW Image File

RAW isn't for everyone or every sort of photography. In the past, I often hesitated recommending the RAW format for general use because the increased file size caused problems in storage, camera speed and processing effectiveness. That cost wasn't necessarily worth it because of the great results that are possible with JPEG.
RAW bestows you control over the image that isn't possible with JPEG, however. It's a valuable format worth considering by any photographer. Nowadays, cameras have become much faster, computers no longer choke on big files, and you can purchase cards with enough memory to allow you to shoot RAW+JPEG for a reasonable price. RAW+JPEG is a great solution, as it lets you gain the most from both formats.

RAW Done Smart
When you begin working on a RAW file in a RAW converter, you're dealing with the best data possible from your camera. For that reason, you should make as many of the major adjustments (brightness, contrast and color) to your image as possible in that converter.

To get the most from your file, you need to do those adjustments smartly. It's important to remember what your photograph is about and why you took it, as this will influence your choices. Arbitrarily adjusting an image based on some sort of "objective" criteria will sooner or later get the photographer into trouble with an image or, at the very least, lead to less than pleasing results. You need to know the purpose of the photograph and make adjustments that support its cause. 
There's no need to overanalyze every photograph you take before opening your image in the RAW converter, as that would be counterproductive. You do need to respect your photograph, however. Using your computer should be about getting the most from your image, not getting the most from the software. The photograph and the photographer should come first.

Auto Settings
When Camera Raw is first opened in Adobe Photoshop CS2, all of the auto settings are turned on by default. The auto settings work, but with varied amounts of success on different photos. You always can adjust any individual auto setting to see if it helps (and sometimes it will).

It seems odd to me, though, to use auto settings for Camera Raw, since this is the epitome of control. Auto settings relinquish your control and allow mathematical formulas to decide what your photo should look like. I highly recommend you unclick all of them, then choose Save New Camera Raw Defaults in the drop-down menu at the right side of the Settings box.

Workflow Options
Once the image is opened, I start at the bottom left of the Camera Raw interface and begin my adjustments from there. Make sure Show Workflow Options is checked.

1. Space. In the drop-down menu of color spaces, I recommend using Adobe RGB (1998) or sRGB (you're always safe with Adobe RGB). Adobe RGB gives the wider color gamut, which can be effective with many photos. You can click back and forth between these two color spaces for comparison.

2. Depth. You have a choice of 8 or 16 bits per channel. This output choice won't affect what you're doing in Camera Raw as the processing is done at the 16-bit level. For most images, outputting at 8-bit is plenty (16-bit largely increases file size).

3. Size. Start with the native file size that your camera produces by selecting the numbers without a plus or minus sign (plus means the file will be increased; minus will decrease the original). If you know you need a large file from your photo, this is a good place to upsize your image.

4. Resolution. This has no effect on image quality, but is here purely for workflow reasons. Output resolution only changes how close or far apart the computer places pixels and doesn't affect their quality. This can be changed later without any harm to the photo.  

Tonal Adjustments
The brightness or darkness of a photo and its contrast have a great impact on how it's perceived by a viewer. Color obviously also has a big effect, but I find it better to start with tonal adjustments unless there are color problems. Here's how to work the tonalities in an image:

1. Highlights. Under the Adjust tab, hold down the Alt or Option key and click on the slider for Exposure. As you move the slider, the bright or colored areas represent highlights. The white is pure white with no detail. Move the Exposure slider to the right to increase bright areas, left to decrease. Click on and off or toggle the Alt/Option key on and off to see how these areas relate to the whole image. This is subjective, but generally you want at least part of your subject bright in most photos.

2. Shadows. Hold down the Alt or Option key and click on the slider for Shadows. Move the Shadows slider to the right to increase dark areas, left to decrease. The black or colored areas represent shadows—the black is pure black with no detail. Again, try clicking on and off or toggling the Alt/Option key on and off to see how these areas relate to the whole image.

3. Midtones. Making the highlight and shadow adjustments usually will make the image too bright or dark overall, even though the shadows and highlights are right. To correct this, move the Brightness slider right or left. This adjustment is even more subjective than the others and is totally a matter of taste. Use a calibrated monitor for best results. A brighter image will let you see more details, but it can lose some of the drama of a darker photo. Don't hold down any keys for this adjustment, however. It also can be useful to try the auto setting here.

4. Midtones 2. If you have Camera Raw from Photoshop CS2, you'll notice a new tab, Curve. This is an excellent tool to deal with midtones, with much more control than Brightness. Under Curve, Tone Curve works the same as Curves in Photoshop ("tone curve" is probably a better name for the latter, but two names for the same thing is confusing), but it comes with some premade adjustments (click on the drop-down menu). You can use the premade adjustments, tweak them or do everything yourself by clicking and dragging points on the curve.
5. Contrast. Back under the first tab of adjustments, you'll see this slider. It affects the overall contrast of the image, but is a bit too heavy-handed for my taste. You gain better control of the contrast by separately adjusting the highlights, shadows and midtones. Most of the time, you can leave it at its default.

6. Compare. It helps to see how the image has changed from how it came into the program. Go to Settings and click Camera Raw Defaults in the drop-down menu to see how the image originally looked, then back to Image Settings to see it now. If you find you've lost something in comparing the two, readjust the image. You can reset the whole thing by holding down the Alt/Option key and clicking on the button that now says Reset at the lower right.
Keep in mind that small adjustments can make a big difference. I often wish this interface had two sliders for each control—one that had the overall adjustment and another for finer tuning. Since it doesn't, realize that small changes can be sufficient. If you have trouble making a small enough adjustment, you can type in new numbers in the box above the adjustment.
Color Adjustments
The color of an image is a tricky thing. A sunset image has a natural color cast, for example. On the other hand, some photos demand a neutral tonality with no color cast at all. Camera Raw lets you do both. You even can tweak whatever color you do have in five ways:

1. White Balance. The White Balance box acts a little like your camera's white-balance settings. You can choose from a number of white-balance presets to jump from one overall color to another.

2. White Balance Tool. This tool will change your cursor to an adjustment tool. Click on something in the photo and it will make it neutral gray. If you try this tool, you always can go back to your earlier "as shot" colors by double-clicking on the tool in the toolbar or using the As Shot choice in the White Balance box.
3. Temperature. The Temperature slider allows you to tweak the image by adding warmth (moving the slider to the right) or adding coolness (moving the slider to the left). For the technical-minded, what you're doing is changing the color temperature setting relative to the original color temperature of the scene as captured. The result is a warming or cooling of the photo.

4. Tint. This is a magenta/green scale that adds green to the photo as the slider is moved to the left and magenta as it's moved to the right. Unless you're after some special effects, it's rare to use large amounts for this adjustment.
5. Saturation. Skip down the interface to find Saturation at the bottom. This is another highly subjective control, and you have to be careful with it. A little addition of saturation (the intensity of a color) goes a long way. A common mistake of many photographers is to increase saturation too much so that the image either looks garish or doesn't reproduce properly outside of Photoshop. That said, many subjects, especially nature, sky, architecture and travel, look better with a slight addition of saturation of 5 to 10 points. With people pictures, it's best to use caution, as the saturation control can make skin tones look unnatural at best and blotchy at worst.

6. Recheck the file for possible readjustment. At this point, I usually reevaluate the overall brightness of the image and either do further tone curve adjustments or Brightness slider adjustments. Since nothing actually has been changed at the image's pixel level, you can adjust and readjust the controls in Camera Raw to your heart's content without hurting your image as it has yet to be converted.

Detail Adjustments
I always check noise issues in an image. In the Detail tab next to the Adjust tab, you'll see three adjustments (CS2 version): Sharpness, Luminance Smoothing, and Color Noise Reduction.

1. Sharpness. Sharpness should be set to zero (it's best not to sharpen the photo at this point in the process).

2. Luminance Smoothing. This affects the general noise that comes from a sensor and may be seen in skies and other smooth tones.

3. Color Noise Reduction. This affects color noise that often comes in dark parts of an image, especially when that image is underexposed.

To use CS2's noise-reduction settings, greatly enlarge your image so you can see any noise. These noise-reduction settings aren't used to get rid of problematic noise, but to reduce normal levels of noise so that the image goes into Photoshop with the highest quality possible. If you use higher settings, check your fine detail to make sure you haven't caused problems with them. With really high levels of noise, you're better off using software programs specially designed to deal with noise problems, such as Noise Ninja, Kodak Digital GEM or nik Multimedia Dfine. 
Save Your Work
The default for Photoshop CS2 is to automatically update your adjusted RAW file's thumbnail in Bridge, which is CS2's image browser. This isn't a permanent change—actually, nothing at all is altered to the image file itself, only the instructions about processing this file have been changed so that it will reopen in Camera Raw with these settings.
To keep this photo with its adjustments, you have several choices at the bottom right of the Camera Raw interface: Save, Open, Cancel and Done.
1. Save lets you save your adjusted image as one of four file types: DNG, JPEG, TIFF and Photoshop (PSD). Plus, it gives you some choices as to how to save these files, such as the location and a new name.

2. Open simply applies the settings on your photo as it converts it to the Photoshop working space. This is the most common use of Camera Raw.

3. Cancel simply cancels everything and returns you to Photoshop.

4. Done merely updates the metadata of the file and returns you to Photoshop without actually opening or saving the image.

Finishing
You'll usually do your finishing work in Photoshop. Raw converters don't let you work selectively on an image, so you must use Photoshop for that. You'll do final tweaking of tones and color, and sharpen the image.


Editor Rob Sheppard's latest book is Adobe Camera Raw for Digital Photographers Only. You'll find his new Website at www.robsheppardphoto.com, which features photo tips and more.


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