Tuesday, April 27, 2010

Dodge and Burn tool

The Dodge and Burn tools are used to lighten (dodge) or darken (burn) areas of the
image. The Dodge tool and the Burn tool are based on a traditional photographer’s
technique for regulating exposure on specific areas of a print. Photographers hold back
light to lighten an area on the print (dodging) or increase the exposure to darken areas on
a print (burning).
Photoshop Photo Manipulation
To use the Dodge tool or the Burn tool
1. Select the Dodge tool or the Burn tool.
2. Choose a brush tip and set brush options in the options bar.
3. In the options bar, select one of the following:
• Midtones to change the middle range of grays
• Shadows to change the dark areas
• Highlights to change the light areas
4. Specify the exposure for the Dodge tool or the Burn tool.

Correct exposure problems and red eye

To add contrast to a photo
If the image needs overall contrast because it doesn’t use the full tonal range,
choose Image > Adjustments > Levels. Then drag the Shadow and Highlight
input sliders inward until they touch the ends of the histogram.
Adjustment layers
An adjustment layer applies color and tonal adjustments to your image without
permanently changing pixel values. For example, rather than making a Levels or
Curves adjustment directly on your image, you can create a Levels or Curves adjustment
layer. The color and tone adjustments are stored in the adjustment layer and apply to all the layers below it.
Adjustment layers provide the following advantages:
1. Nondestructive edits. You can try different settings and re-edit the adjustment
layer at any time. You can also reduce the effect of the adjustment by lowering
the opacity of the adjustment layer.
2. Reduced loss of image data through combined multiple adjustments. Each
time you adjust pixel values directly, you lose some image data. You can use
multiple adjustment layers and make small adjustments. Photoshop combines all
the adjustments before it applies them to the image.
3. Selective editing. Paint on the adjustment layer’s image mask to apply an adjustment to part of an image. Later you can control which parts of the image are
Photoshop Photo Manipulation adjusted by re-editing the layer mask. You can vary the adjustment by painting on the mask with different tones of gray.
4. Ability to apply adjustments to multiple images. Copy and paste adjustment layers between images to apply the same color and tone adjustments.
5. Adjustment layers increase the image’s file size, though no more than other
layers. If you are working with many layers, you may want to reduce file size by
merging the adjustment layers into the pixel content layers. Adjustment layers
have many of the same characteristics as other layers. You can adjust their opacity
and blending mode, and you can group them to apply the adjustment to specific
layers. You can turn their visibility on and off to apply their effect or to preview
the effect.
To create an adjustment layer
Do one of the following:
• Click the New Adjustment Layer button at the bottom of the Layers
palette, and choose a layer type.
• Choose Layer > New Adjustment Layer, and choose an option from the
submenu. Then name the layer, set other layer options, and click OK.

Manipulating your Digital Photos with Photoshop

Whether you have digital photographs or photographs that you have scanned
electronically, you may find that there are times that you would like to manipulate them. This manipulation may include cropping the photo, getting rid of red eye, erasing dust spots or repairing scratches. This seminar will walk you through the process of correcting “not so perfect” photographs as well as working with images to create panoramas, digital contact sheets and customized picture packages as well as save files in the appropriate file format.

NOTE: There are direct links to help documentation for the information covered in
today’s class. In Photoshop CS2, go to: Help > How to Enhance Photos
Before you begin: It is best practice to save a working copy of your photograph in
Photoshop (.psd) format before you begin working on it. Typically digital cameras save your images in a .jpg format. Because JPG files are designed to be compressed (relatively small files), you will notice that if you leave the file as a JPG, you will begin to lose image quality during the editing and resaving process. JPGs are referred to as a lossy file type “with losses” to image quality. They are small files without the requirement for full recoverability. Later you can save to a specific format for either print or the web. Keeping the file in .psd format gives you the flexibility to export to various file formats to keep imagines consistent from one medium to the next (ie. .jpg for the web, .tiff or .eps for print) Choosing an Image Mode You can convert Photoshop images to a number of images or color modes, such as grayscale, RGB or CMYK. The mode you specify controls how color information is defined in the image. By selecting a particular color mode, you are choosing to work with a particular color model (a numerical method for describing color). You should specify an image mode based on the range of colors that you want the image to display and the image’s intended use, such as screen or print. Color modes determine the number of colors, the number of channels, and the file size of an image. Choosing a color mode also determines which tools and file formats are available.