iPhoto comes with some powerful tools for tweaking the images you took with your camera. In the Edit window, below the image, is a set of tools for automatically and manually adjusting images. On the right side is Adjust: manual controls for adjusting an array of image "exposure" settings (brightness, contrast, tint, and so on). In the middle are buttons for one-click "magic" image controls.
The most impressive of these tools is the simple power of Enhance.
Making Changes with Enhance
Let's go back to the fish image we just cropped. It's a little dark, and not quite as crisp as it could be.
iPhoto does a quick analysis of your image and determines the best way to adjust brightness, contrast, color balance, and white balance in order to improve your image.
It doesn't always work perfectly, but it's pretty good, and most images benefit.
If you don't like the results of Enhance, press Command-Z to undo it.
If Enhance didn't help, you can try your hand at using the manual image-adjustment tools which you can access by pressing the Adjust button. The adjust tools offer a range of functions comparable to those in dedicated image-manipulation software, but can be confusing for novices. If the automatic Enhance looks inappropriate to your photo, experiment with the sliders in Adjust. For power users, if Adjust isn't enough, you can tweak the image with more-professional tools.
Go through all of the images in all four albums, and crop or enhance until you are satisfied with them.
If you're using a flash, it's not uncommon to end up with that satanic-looking red-eyethe bane of photographers everywhere. It's caused when the flash reflects off the subject's retina and creates that characteristic glow. Some cameras minimize red-eye by shining a light for a moment before the actual photo is taken; this causes the pupil to constrict before the flash goes off and therefore reduces the retina reflection. Not all cameras have this feature, and even if they do, they don't catch every incident.
If you don't get rid of red-eye when you shoot, you can do it on your Mac. iPhoto simply does a little color correction on your subject's eyestaking that which was red and making it black.
When you're done working in the Edit window, click Done to save your work and return to the main iPhoto window.
Straightening Crooked Photos
When you're holding your camera taking pictures, it is very easy to snap a shot that's crooked. With many images it might not be a problem; maybe it's not distracting. But in images with distinct horizontal or vertical elements (flagpoles, the ocean horizon, and so on), an important adjustment is the ability to even up those awkward angles. iPhoto makes this simple.