iPhoto 6 now allows you to create a slideshow of a Photo Book. Before you could only watch a slideshow of single, full screen photos but now you can do this will the pages of your photo book. iPhoto has always allowed you to export a normal slideshow to a Quicktime movie, but this option doesn't appear to be available for photo book slideshows. However there's a secret way of doing this.

Start by creating your photo book. Do this by clicking on the new book button at the bottom of the window and giving your book a name. Notice that it now appears in the sidebar. To add photos to the book, browse your library and drag the photos you want to the photo book entry in the sidebar. When you have added all you want, click on the photo book. You can now enter the title and description and any other information about your photos. Place them in the book by dragging them from the toolbar at the top into the photo frames in the book. If necessary, add extra pages by clicking the corresponding button at the bottom of the window.

Once your book is completed, you can view the slideshow by clicking the play button at the bottom. This will bring up the slideshow options. Make sure the random order check box is unchecked (you don't want your pages appearing in a random order) and choose the amount of time you want each page to appear for. To make the movie more book-like you will probably want to use the "page peel" transition, going left. You might also want to add some background music from your iTunes library.

Now if you click play, the slideshow will begin full screen. Check it appears exactly how you want it. Now how do we get this into a movie you can save? Exit the slideshow to return to your photo book. Now hold the Option key and click the play button again. You will get the same slideshow settings as before. Check they are all right and click play.



Instead of going to the slideshow, you will now be prompted to choose a location to save your movie. Give it a name and click export. Now your photo book is saved as a Quicktime movie that you can watch and share.

One handy feature of iPhoto 6 is its ability to easily compare two photos side by side. This allows you to choose the best of two similar shots, or duplicate a photo and try out enhancements on one copy while comparing it to the original.

To use this photo comparison tool, you need to have iPhoto set to edit in the main window. Go to the iPhoto menu and choose Preferences. Set the drop down menu to edit photos in main window. Now go back to your photo library and decide on two photos to compare. Click the first one, and Command-click the second (i.e. select them both). Now double-click on one to enter the edit mode.

iPhoto will show your images side by side, ready for you to crop, enhance and retouch them. There are a few additional tricks to this as well. You can select more than two photos by just selecting more at the start (by Command-clicking). If you want to replace one of the photos you are comparing, click on it and then choose a different one from the thumbnail browser at the top of the window. If you want to add in a new photo to compare, Command-click on one of the thumbnails in the browser. To remove an image from the comparison, Command-click it in the thumbnail browser again.

A slightly different way of doing this is to edit in full screen mode rather than in the main window. You can do this by Right-clicking (Control-clicking) on you selected photos and choosing edit in full screen mode.

If you have a large photo album, you can quickly see iPhoto start to take up large amounts of hard drive space. One reason for this is that every time you modify a photo (rotate, enhance, etc.) it creates a backup original. This is to allow it to have that magical "Revert to original" option.

If you have decided that you don't want your originals any more, getting rid of them can reduce the amount of hard drive space that your photo library takes up. There are two ways of doing this - using a few terminal commands, or using a free application called iPhoto Diet.

The terminal commands are from this MacRumors forum and come with a brief explanation of what they do. To run them, paste the following into the terminal:

mkdir ~/.Trash/iPhoto-Originals
cd ~/"Pictures/iPhoto Library/Modified/"
find . -type f -exec mv "../Originals/{}" ~/.Trash/iPhoto-Originals/ \;

This gives you a folder in the trash so you can check all the right photos are there before emptying it permanently. A summary of everything in the MacRumors forum has been made by Adriaan Tijsseling on his blog.

iPhoto Diet is a free application by Martin Fuhrer that does the same thing, but with more options and a nice user interface. This may take a little more time than the terminal commands, but it is much more user friendly and gives greater flexibility. It allows you to reduce you photo library size in the following ways:

• eliminate duplicate photos created internally by iPhoto or imported by yourself
• remove iPhoto's backups of rotated or modified photos
• strip the thumbnail icons of your photos
• remove thumbnail photos that have become mixed up with your high resolution photos
• identify photos which have not been added to albums
• weed out unnecessary folders and files from the library
• and more!

Download Links, installation instructions and an FAQ are available from Martin Fuhrer's site.

The built-in red eye and retouch editing tools in iPhoto are amazingly easy to use, but pretty basic in what they can do. Luckily, in iPhoto 6 there is a secret advanced editing mode that allows you to make these tools even more useful. When this mode is activated you can control the size and strength of both the retouch and red eye tools.

First off, you need to check your settings are right. Load up iPhoto and go to the Preferences located in the iPhoto menu. You can only access the advanced editing mode if you have iPhoto set for image editing. Also, if you have iPhoto set to edit in a separate window, the advanced editing mode will be reset every time you enter edit mode. Choosing "Edit in Main Window" will make the advanced editing mode stay active until you quit iPhoto.

As usual, you need to double-click any image to enter edit mode. Choose the tool that you need (either retouch or red eye) by clicking on the icon at the bottom. Once this is selected, press Control-Caps Lock-9 at the same time, then release them. At first nothing will happen, but you are now in advanced editing mode. Pressing tab will cycle through the different advanced features, which will be shown by the cursor changing shape.

If you chose red eye, pressing tab once will switch the small cross hairs cursor to a large oval. Now, pressing the [ and ] keyes will allow you to resize the area of red eye correction. Pressing shift while clicking to apply the red eye correction will result in a lighter fill than with the normal tool.

If you chose retouch, pressing tab once will change the cursor to a circle with a number below it. This shows the size of the retouch tool. To resize it, press the [ and ] keys as with the red eye tool. To change the strength of the retouch, press Shift-[ and Shift-] and the number will change to show this. If you press tab a second time, the retouch tool changes into the lighten tool, which just lightens the area under the circle. As with the other tools, press [ and ] to resize it. Pressing tab again will bring you back to the normal retouch tool.

Quitting and re-launching iPhoto will return you to the normal editing mode, so you need to redo the Control-Caps Lock-9 keyboard shortcut if you want to enter the advanced mode again.

There is a simple way to speed up iPhoto considerably, especially if you are running it on an old machine.

Open up iPhoto and go to the Preferences. Choose Appearance. If you uncheck Outline and Drop shadow, then slide the background all the way to white, you should notice that iPhoto starts up a lot quicker. This mainly helps with iPhoto 5's performance, as iPhoto 6 is already much snappier.

If you still find iPhoto to be slow, try holding down the command and option keys while its starting up. A diolog box should load up, asking if you want to rebuild your photo library. This has the greatest effect if you have a very large photo libary.

One final tip is to press 0, 1 or 2 while in your library. This sets your photos to one of the 3 default sizes, which load a lot quicker than the custom sizes you get when dragging the slider.

Now your iPhoto library should scroll like butter!

In the System Preferences it is easy to make your desktop cycle through a series of images. Just open up System Preferences and click the desktop and screen saver section.

At the bottom of the desktop tab there is an option to change the picture for a given amount of time. With this selected, your desktop will cycle through the images in the iPhoto album or folder you have selected.

But what if you want a selection of photos that aren't in an album together, or want to use multiple albums? Open up iPhoto and click on any image. Clicking on the "desktop" button at the bottom will set this image as your desktop background. Select multiple images using shift-click (if they are in a row) or command-click (if they are separated by other photos), and click the desktop button. If you open up system preferences now, you can see that your desktop is set to cycle through these images.

An added quirk is that your screen saver is also set to make a slideshow of these pictures.