Basic Processing of RAW Images

An easy way to view and edit your RAW files is to view then in Adobe Bridge and then open them in Adobe Camera Raw. Both of these programs come with Photoshop when you buy it. Here is what to do:

Open Adobe Bridge and navigate to the directory containing the RAW image you want to work on.
If you are using the "default" view your screen will be similar to the above image.

1. This is the "navigation" area that lets you select the folder (directory) that contains the images you want to view.
2. This is the "filter" area that lets you display a subset of the images in the selected folder.
3. This is the "content" area that shows thumbnails of all the images in the folder (or a subset of them if you have applied a filter).
4. This is the "preview" area that displays a larger version of the image if you click on a thumbnail - in the screenshot above no thumbnail is selected so there is no image in the preview area.
5. This is the "metadata" area that displays detailed information about the image whose thumbnail is selected. Nothing is shown here in the example because no thumbnail has been selected.

1. Click on the thumbnail of the RAW file you want to edit.
2. A larger "preview" image will appear in the top right hand corner of your screen, and
3. Some data about the image will appear below it. Exactly what data you see here will depend on what preferences you have set up in Bridge.
4. Note: If your view of Bridge is very different from the one shown here, try clicking on the preset view buttons at the bottom right of the screen. (These buttons are at the top right of the screen in the CS4 version of Bridge.)

In the CS3 version of Bridge you will see the following data:
1. The metadata - starting with exposure information, ISO setting,etc.
2, More detailed information about the file (such as the colour mode and bit depth settings from the camera).
3. The EXIF data that tells you about the camera, the lens, the flash, etc.
You may also see additonal data - depending on the preferences you have set for Bridge.

If you double-click on the thumbnail of the image in Bridge it should open in Adobe Camera Raw. [If this does not happen you need to change the preference settings for Adobe Bridge.]

When the file opens, the Adobe Camera Raw screen will look something like the above screenshot, with these main parts:
1. The image
2. The buttons to select various tools.
3. The information and adjustments section.
4, The workflow options section.

NOTE: The first time you open the RAW file in Adobe Camera Raw it will be displayed using some information (e.g., white balance, exposure) that was recorded by the camera at the time you took the photograph AND default setings that are built into ACR. If you think that the image is perfect and does not require any adjustments then you can transfer the file to Photoshop by clicking on the "Open Image" button at the bottom right of the screen. If you decide that some adjustments are necessary you need to select the appropriate tool (see below).

THE TOOLS APPEAR AT THE TOP LEFT OF THE ACR SCREEN. By clicking on a tool you can perform the following basic operations:

1. Zoom tool. Select the tool, move the cursor to the part of the image that you want to magnify and click. Each time you click, the image is magnified further. If you hold down the "Alt" key as you click the image size will be reduced. The size of the image (percentage) will appear in the bottom left hand corner of the screen. Near this image size there is a double-header arrow - you can click on it and select a new image size. If you double-click on the zoom tool the image size will change to 100%. You will need to have the image at 100% magnification or higher to see the effects of some adjustments.
You can magnify a selected part of the image by clicking and dragging a marquee around the area to be enlarged.

2. Hand tool. Select the tool, move the cursor to any part of the image, click and drag to move the image around the screen. This is very useful if the image is too large for all of it to fit on the screen.

3. White balance tool. Selecting this eyedropper allows you to make a "one-click" adjustment to the white balance. This is dealt with in detail in a separate tutorial.

4. Colour sampler tool. This allows you to add sample points to the image. As you add a sample point the RGB values at that point are shown just beneath the tool bar.You can add up to nine sample points. As you make colour or tonal adjustments the RGB values at these sample points will change. For more information, refer to the white balance tutorial.

5. Crop tool. Select the tool and then click and drag on the image to select the part of the image that you want to keep. When you release the mouse button the rest of the image will be greyed out. You can change the size and shape of the cropped area by clickiing and dragging the corners of the cropped area. If you place the cursor just outside one of the corners of the cropped area it will turn into a curved arrow, click and you can rotate the cropped area. If you "click and hold" on the crop tool (or select the crop tool and "right click" anywhere in the image) you will get a drop-down menu that lets you select fixed cropping ratios (such as "2 to 3").

6. Straighten tool. Select the tool, click on the image and drag a line across something (such as the horizon) that should be level. When you release the mouse button ACR will apply crop marks and grey out part of the image to show the effects of the straightening. You can change the size of teh cropped area just as you do when the crop tool has been used. When you press the "enter" key the straightening and cropping is applied. If it is more convenient, you can drag the straightening line along something that is supposed to be vertical (such as the edge of a building).

7.Retouching tool. When you select this tool two options appear just below the tool. The first is "radius" and this lets you select the size of the tool. The second is a heal/clone choice. Healing allows you to quickly remove spots and blemishes. With the healing tool selected just click on an unwanted spot/blemish, drag to enclose the spot in a red circle and release the mouse. A second (green) circle will appear to show what area is being used as the reference point for texture and tonal adjustments. You can click and drag inside either circle to move that circle and you can click and drag on the edge of the circles to change their size. You can apply as many healing circles as you like to an image. The "clone" option works in a similar way but it is more effective to do cloning in Photoshop. When the retouching tool is selected, a "Show Overlay" tick box appears just above the top righthand corner of the image. This allows you to turn off the visibility of the heal/clone circles.

8. Red-eye removal tool. Select the tool, click just outside the pupil of the red eye and drag a rectangle that is slightly larger than the eye. When you release the mouse button the red should disappear. You have two options with this tool (and they appear just below the tool bar). "Pupil size" allows you to adjust the size of the pupil and "darken " allows you to change the opacity of the pupil.

9. Preferences. Click on this icon to open a preferences dialogue box to change some of the basic preferences in ACR.

10. Rotate. Click once to rotate the image counter-clockwise by 90 degrees.

11. Rotate. Click once to totate the image clockwise by 90 degrees.

There is more information about some of these tools later in this tutorial.

TIP: Whatever tool you have selected, if you hold down the spacebar the cursor will change to the "hand" and you can click and drag the image around in the image window. When you release the space bar the "hand" will change back to whatever tool you had previously selected.

Just above the top right hand cormer of the image there are two small symbols:
1. Clicking on this allows you to toggle between a full screen view of the image and a smaller view - use whichever view suits you best.
2. A preview check box. MAKE SURE YOU HAVE A TICK IN THIS BOX because if you do not the image you see on the screen will not change as you make adjustments.

In the top right hand corner of the ACR screen you will see a histogram - this is similar to the histogram you can display on your camera at the time you take the photograph (obviously this depends on what type of camera you have) and it is similar to the histogram you can display in Photoshop.

The histogram indicates the number of pixels at each luminance value in an image. The left hand end of the histogram represents black (red, green and blue channels all zero luminance) and the right hand end represents white (red, green and blue all at their maximum luminance). The horizontal scale on the histogram represents 256 different luminance values (from 0 to 255). A histogram that has nonzero values for each luminance value indicates an image that has a full tonal range. A histogram that doesn’t use the full tonal range may look dull and lack contrast.

The histogram is made up of three layers of colour that represent the red, green, and blue colour channels. White appears when all three channels overlap; yellow, magenta, and cyan appear when two of the RGB channels overlap (yellow equals the red + green channels, magenta equals the red + blue channels, and cyan equals the green + blue channels).

There is no "ideal" shape for a histogram - it will vary according to the colour and luminance of the image.

The histogram can help you determine whether or not the captured scene fits within the camera's dynamic range (that is, whether or not your camera has been able to capture detail in both the darkest parts of the image and the lightest parts of the image).
If the histogram has a spike at the extreme left hand end this indicates "shadow clipping" - some of the detail in the shadows has been lost because details that are not really "black" have been interpreted as black by the camera.
If the histogram has a spike at the extreme right hand end this indicates "highlight clipping" - some of the detail in the highlights has been lost because details that are not really "white" have been forced to be white by the camera.
If there's no clipping at either the highlight or the shadow end, then the luminance values in the image fall within the dynamic range of your camera. That is, the camera has been able to reproduce all the different luminance levels in the scene.
If there's clipping at both ends then the range of luminance levels in the scene is wider than the range that your camera can record.
If there's clipping at only one end, you may be able to rescue highlight or shadow detail - see later for guidelines.

The histogram changes automatically as you adjust the settings (e.g. exposure or brightness) in Adobe Camera Raw.

You will notice that there are little "triangles" in each of the top corners of the histogram panel.
If you click on the triangle on the left and then look at the image you will see that the under-exposed areas (those that are clipping) will be shaded blue.
If you click on the triangle on the right and look at the image you will see that the over-exposed areas (those areas that are clipping) will be shaded red.

This is a handy feature that will help when you are making exposure adjustments, so I suggest that you always leave the "shadows clipping warning" and the "highlights clipping warning" tools turned on. When a clipping warning is turned on there will be a white square around the corresponding triangle. If clipping is occuring the colour of the triangle will change to reveal which channel is clipping (if it is white then all channels are clipping).

With the "highlights clipping warning" turned on, you can see a large red area in the bottom left and a small red area in the top right of this sample image - these are areas where the image is "blown out" or over-exposed to the extent that there is no detail visible. The highlights have been "clipped".
You can't see it in the screen shot above, but there is also a small blue area on the bird's wing where the "shadows clipping warning" is indicating that a small area is totally black and has no visible detail.

You will see how useful these clipping warnings are as soon as we start to make adjustments to the image.

1. Just below the histogram is an informaton pane that displays basic informaton about the camera settings (aperture, shutter speed and ISO setting) and the lens (in this case an 80-400mm zoom lens set at the 400mm end of its range).

2. The RGB (red, green, blue) values displayed here are the values immediatley under the cursor - they change as you move the cursor around rthe image.

Below the information pane there is a row of eight buttons that allow you to select different groups of adjustments.

When you click on a button its name appears below the row of buttons ("Basic" in this example) and the corresponding set of adjustment sliders appear below that.

Normally you shoould work through these sets of adjustment buttons from left to right.

For many images, the only adjustments you will need to make are those that are revealed when you click on the "Basic" button.

When you select tthe "Basic" adjustment button you are presented with the adjustment options show above.

Normally you will work through these adjustments from the top (White Balance) down to the bottom (Saturation).

Notice that on the right hand side of the strip where the word "Basic" appears there is a small symbol with an arrow next to it. If you click on that small arrow it will reveal a drop-down menu similar to the following:

If there is a tick beside the "Camera Raw Defaults" then the adjustment sliders should all be in the positions shown in the previous screenshot - all on zero except for "blacks" (5), "brightness" (+50) and "contrast" (+25).

You can learn later how to set up other "preset" values for the slider settings.

The white balance information recorded by your camera is referred to in Adobe Camera Raw as the "As Shot" white balance. The information displayed is the "colour temperature" (5300 in this example) and the "tint" (+39 in this example).

If you have set your camera on "auto white balance" it will probably do a fair job of recording the correct colour informatoin and you will not need to make any white balance adjustments in Camera Raw. However, under unusual lighting conditions you may get an unwanted colour cast - in this case you need to adjust the white balance. To do this you have three basic options in Adobe Camera Raw - presets, the eyedropper and the sliders. However, this is not the only way to achieve "correct" white balance.

Normally what you are trying to achieve is the "correct" white balance - that is, neutral greys that are really neutral so that there is no unwanted colour cast on the image.

I have created a separate tutorial to explain various ways of adjusting white balance. You can find it at this web address: http://roykillen.screenstepslive.com/spaces/175/buckets/227/lessons/935-MAKING-SENSE-OF-WHITE-BALANCE-

When you have adjusted the white balance you are ready to make tonal adjustments. The basic tonal adjustment controls, set to their default values are shown below.

In the CS3 version (and the Elements 6 version) of Camera Raw there are six sliders that allow you to adjust the tone of the image.

1. "Exposure". Moving the Exposure slider produces linear changes in brightness by moving the histogram to the left or right. The units at the right-hand end of the Exposure slider are Exposure Values (EVs) (like the exposure compensation controls on your camera). If you set the Exposure slider to -1 EV, the effect is approximately equivalent of a 1 stop reduction in photographic exposure in the camera. If you move the exposure slider too far it will cause clipping of either the highlights or shadows. If you hold down the "Alt" key as you drag the Exposure slider areas of the image that are clipping will be highlighted. Watch the histogram as you move the Exposure slider. Avoid making adjustments that will cause clipping (becasue this means you are losing information from the image).

2. "Recovery". Moving this slider to the right attempts to recover lost detail in "blown out" highlights. It darkens the highlights (you can see the right-hand end of the histogram moving to the left) without making any changes to the left hand end (the dark areas of the image).

3. "Fill Light". Moving this slider to the right attempts to recover lost detail in the shadows by lightening the dark areas of the image without affecting the highlights (very much). Be careful not to take this too far as it tends to bring out noise in the shadows.

4." Blacks". Moving this slider to the right changes the black clipping point (the level of light that is forced to be totally black). It darkens the darkest parts of the image without having much influence on the rest of the image. It's effect is similar to moving the left-hand slider in the "levels" dialogue in Photoshop.

5. "Brightness". Moving this control changes the brightness of the image without changing the white point (the level at which highlight clipping occurs) or black point (the level at which shadow clipping occurs). Its effect is similar to moving the gamma slider (centre slider) on the "levels" dialogue in Photoshop. It's default setting is 50. Set the black and white points (with "blacks" and "exposure") before adjusting the brightness.

6. "Contrast". This alters mid-tone contrast without altering the black point or white point. Moving it to the right is similar to creating an "s-curve" in the Photoshop curves dialogue (lightening the light tones and darkening the dark tones). The default setting applied by ACR is 25. This should be the last adjustment you make in the "tonal adjustments" group of sliders.

1. "Clarity". This control produces localised contrast changes in areas of the image that contain detail. It can be used to make hazy images a bit clearer and to add some "punch" to dull images. It also gives the impression of sharpening the image - the effect is a bit like the "unsharp mask" filter in Photoshop.

2. "Vibrance". This is like a "smart" saturation control. Moving it to the right increases the strength (saturation) of colours, moving it to the left reduces saturation. It is "smart" because it has very litte effect on colours that are already saturated and it has very little effect on skin tones.

3. "Saturation". This slider increases (or descreases) the colour strength (saturation) of all colours in the image.

There is a good video demonstration of the difference between using the vibrance and saturation sliders at this web site: www.adobe.com/designcenter/lightroom/articles/lir1am_vibrance.html#
The demonstration uses Adobe Lightroom but the procedures and the results are the same in Adobe Camera Raw.

The image below demonstrates the difference between the vibrance and stauration controls.

The image at the bottom left was the result of moving the saturation slider all the way to the left - all the colours in the original image (top) are desaturated.

The image at the bottom right is the result of moving the vibrance slider all the way to the left - the saturated colours (eg the red jumper) and the skin tones are affected less than the colours that were not saturated (eg the colours in the background).

A similar thing happens when you increase the saturation or vibrance - I used desaturation in the example because it is easier to see the effect in this image.

The next three tools are curves, details and HSL (hue/saturation/luminance).
You may choose to do these adjustments in Camera Raw or you may decide that you prefer to do them in Photoshop. My preference is to make the initial adjustments in Camera Raw and then do some fine tuning in Photoshop.

Something to keep in mind is that if you make these adjustments in Camera Raw they will be appplied to the whole image. If you make them in Photoshop you can use adjustment layers and masks to limit the effects to selected parts of the image. If you are using CS4 you can localise these adjustments with the new adjustment tool.

A brief description of these tools is given in the tutorial that you will find at: http://roykillen.screenstepslive.com/spaces/175/buckets/227/lessons/920-Processing-RAW-images-Stage-2-Curves-Sharpening-and-HSL

Comments on this tutorial are welcome.

Roy Killen
Updated 17th April 2009
Email: roykillen@mac.com