Fading images in and out (a la PBS documentaries)

I have been saying in class that to fade a photo or image in or out of your Flash movie you'll need to use a shape tween. But this is incorrect. And it has been frustrating me as it is the way it has been done for a long time.

Flash 2014 will not shape tween a photo or image or bitmap unless it has been converted into a vector shape. And converting to vector (Modify->Bitmap->Trace Bitmap) is decidedly rough on your image. It will look terrible.

So how do you gently fade in/out a photo or block of text in your Spash Screen? Motion tween. Plop your image on the first frame of the block. Convert to Symbol->Graphic (Motion tweens require symbols -- this is opposite of shape tweens). Add the Motion Tween -- this creates the long blue block of frames. At the end of the blue block, insert a keyframe (it will look like a small black diamond as opposed to the normal black circle). With that diamond frame selected, change the alpha of your symbol in the Properties panel. You can also move it if you wish to have the image slide in or out of the stage.

I have come to the conclusion that the type of tween you use is really based on the object you have. Vector shapes? Go for a shape tween. Images/bitmaps/psd/png/jpeg/gif/etc go for a Motion tween. Both can let you move/change alpha. If you need to change the shape of something (morph) you will need to be vector so you can use a shape tween.

Last bits of difference: shape tweens look at the first keyframe and the one immediately after to figure out what to do. They need simple vector (drawing) objects.

Motion tweens look at the first keyframe and any changes within the blue tween box. They do not care if there is a black circle keyframe at the end. You make changes by adding special keyframes within the blue frames. Motion tweens require symbols.