Using Picasa for basic editing
You can make simple editing such as cropping, straightening, removing redeye, retouching blemishes, or adding text on your photos. If you need to adjust the lighting of your photos you might use Picasa for that. The Picasa editing tools let you manipulate the lighting of your pictures.
“Fill Light”: uses a slider that brightens a backlit or dark photo while preserving the details in lighter areas of the picture.
“Highlights”: uses a slider that brightens the overall appearance of a picture, causing the light areas to become lighter. Use Highlights together with Shadows for best results.
“Shadows”: uses a slider that darkens the overall appearance of a picture, causing dark areas to become more distinct. Use together with Highlights for best result.
If you want more control on the changing brightness of the photo you can click on Edit in Picnik , that will take you online photo editing tool. Picnik has more features to edit photos online.
Do not forget Picasa is a free software, easy to use but do not expect to find fine tuning elements like Adobe® Photoshop® Lightroom has, or any other paid photo editing softwares.
‘Tuning’ tab features
Click on one of the tools from the Tuning tab to make changes.
At times, photos with bright backgrounds can darken or compromise important details in the photo. Add fill light to the foreground of photos, making them more balanced.
Increase the highlights to amplify the bright spots of your photograph. It can help make the whites in your composition more vibrant.
Auto Lighting Fix
Click this magic wand to have Picasa automatically set the brightness and contrast to optimal levels, while preserving a photo’s color values.
Darken the shadows in your photo to provide additional depth or contrast. Use this in conjunction with the Highlights slider to add contrast to a flat-looking photo.
Make your photos warmer by sliding the ticker to the right. This can make your colors more vivid and help bring to life the composition of your photograph.
Neutral Color Picker
Tell Picasa which part of your photo it should treat as gray or white. Photo Lab will then use that selection to balance the colors in the photo.
Auto Color Fix
Click this magic wand to have Picasa automatically remove color cast and restore the color balance, while preserving contrast and brightness values.
These two buttons, only active when there are unsaved edits on the photo, undo and redo your edits in the order they were applied.
Google’s Picasa software lets you organize, edit, and upload your photos online.
Learn more about Picasa http://support.google.com/picasa/answer/157000?hl=en&
Download Picasa at http://picasa.google.com