Adobe Photoshop CS5 for Photographers - Martin Evening [87]
Figure 3.24 The Camera Raw crop tool menu includes a range of preset crop proportions. You can add your own custom presets by clicking on Custom… (see Figure 3.25 below).
How to crop and straighten
1.
To straighten a photograph, I selected the straighten tool from the Camera Raw tools and dragged with the tool to follow the line that I wished to have appear straight.
2.
This action straightened the image. I could then click on the crop tool to access the crop tool menu and choose a crop ratio preset, or click on Custom… to create a new setting.
3.
After creating and selecting a new custom 16:9 crop ratio setting, I dragged one of the corner handles to resize the crop bounding box as desired.
4.
Finally, I deselected the crop tool by clicking on one of the other tools (such as the hand tool). This reset the preview to show a fully cropped and straighten-aligned image.
Basic panel controls
The Basic controls ( Figure 3.26 ) are best approached and adjusted in the order you find them. I therefore suggest you start by adjusting the white balance adjustments first before working your way down the list. Having said that, you don't necessarily have to follow a strict order here, although it is always important to set the Exposure slider first before you adjust the Brightness slider.
Figure 3.26 The Camera Raw Basic panel controls.
White balance
Let's start though with the white balance controls. These refer to the color temperature of the lighting conditions at the time a photo was taken and essentially describe the warmth or coolness of the light. Quartz-halogen lighting has a warmer color and a low color temperature value of around 3400 K, while daylight has a bluer color (and a higher color temperature value of around 6500 K). If you choose to shoot in raw mode it does not matter how you set the white point settings at the time of shooting, because you can always decide later which is the best white balance setting to use.
Camera Raw was first designed by Thomas Knoll, who was one of the original creators of the Photoshop program. Camera Raw cleverly uses two profile measurements, one made under tungsten lighting conditions and another made using daylight balanced lighting. From this data, Camera Raw is able to extrapolate and calculate the white balance adjustment for any color temperature value that falls between these two white balance measurements, as well as calculating the more extreme values that go beyond either side of these measured values.
The default white balance setting normally uses the ‘As Shot’ white balance setting that was embedded in the raw file metadata at the time the image was taken. This might be a fixed white balance setting that you had selected on your camera, or it could be an auto white balance that was calculated at the time the picture was shot. If this is not correct you can try mousing down on the White Balance pop-up menu and select a preset setting that correctly describes which white balance setting to use. Alternatively, you can simply adjust the Temperature slider to make the image appear warmer or cooler and adjust the Tint slider to balance the white balance green/magenta tint bias.
Using the white balance tool
The easiest way to set the white balance manually is to select the white balance tool and click on an area that is meant to be a light gray color ( Figure 3.28 ). Don't select an area of pure white as this may contain some channel clipping, which will produce a skewed result (which is why it is better to sample a light gray color instead). You will also notice that as you move the white balance tool across the image, the sampled RGB values are displayed just below the histogram, and when you click to set the white balance, these numbers