Capture the contents of your entire desktop at the same time as your video camera, microphone and computer’s audio. Sophisticated editing tools allow you to create incredible screencasts in no time.The finished result is a QuickTime or Windows Media movie, ready for publishing to your website or blog.

Benefits:
Teachers can use ScreenFlow to record their lectures, tutorials, or instructions for students, or to create rich-media presentations. The beauty of ScreenFlow is that they only need to record their message once and students can access the video at any time that fits their schedule.

ScreenFlow Trial Version can be downloaded from here:
http://www.flip4mac.com/screenflow_download.htm

Learning ScreenFlow Features:

1. Trimming Clips
Use ScreenFlow to record some events on your Desktop (move folders around, open and switch between applications, and so on—see our first how-to for more on Screenflow’s basic recording features). Once you’re done, the editing interface launches and the footage you took is automatically placed in the Timeline, ready to be modified. Start by trimming the beginning to just before something interesting happens. To do that, click on the clip to select it (it gets highlighted in yellow), then drag the playhead to the desired place on the Timeline. Next, go to Edit > Trim Front To Scrubber (or use the keyboard shortcut W).

2. Fade
With the footage still selected, go to the panel on the right and choose the Video tab (the first icon, top left of that section). Click the Add Video Action button. A yellow rectangle is added where the playhead had been located. Move the playhead to the start of that rectangle and change the Opacity slider located in the Video tab to 0% to create your first fade-from-black transition.

3. Stretch the effect
Altering the length of the effect is very straightforward: Move the cursor to the end of the effect, and it turns into a resize tool. When that happens, click and drag the rectangle’s edge to either lengthen or shorten the effect. You can also choose to reposition it somewhere else on the clip by clicking and dragging it.

4. Removing some portions
There might be a section in the middle of your footage that you’d rather not use, in order to speed up your screencast, for instance, or to remove a glitch. To do so, move the playhead to the beginning of the part you want to trim. Go to Edit > Split Clip (or use the Shift-Command-T keyboard shortcut). Move to the end of the unwanted clip, click on it to select it, and perform the same action. Hit the Delete key to remove the middle part from the Timeline.

5. Layers
Now that we have two clips in the Timeline, let’s work with multiple layers. Click on the second part and drag it straight down to place it on another layer. Then, drag it so that about a second of it overlaps the one above. Next, click on the first clip’s fade effect from step 2 to select it. Copy that effect (Edit > Copy or Command-C).

6. Cloning Away
Move the playhead so that it is at the start of the second clip (the playhead should snap to the edit point as you near it; if it doesn’t, go to View > Snapping). Select both clips by clicking on one and Shift-clicking on the other. Then, paste the copied effect (Edit > Paste or Command-V) to add it to both clips at the same time.

7. Effect Alteration
With the playhead still in the same place, select the new top effect (make sure it’s the only selected item in the Timeline). Its Opacity slider should be at 100%. Select the bottom effect; set that Opacity to 0%. Move the playhead to the end of the top clip. Change the top effect’s Opacity to 0% and the bottom effect to 100%. You’ve just created a cross-dissolve.

8. 3D
Move the playhead to the right of the cross-dissolve. Select the last clip and use the keyboard shortcut Command-K to create a new Video Action. Use the panel on the right to change the Scale to 40-50% and the Y rotation to -45 degrees. Play back the effect and watch your Desktop shrink and rotate clockwise.

9. Animate
You can use actions to animate absolutely anything. For instance, move the cursor so that it’s a second or so after the rotation effect. Create a new Video Action. This time, tick the Reflection box and move the slider until it reaches 70%. Next, drag the new effect until it touches the previous one (actions cannot overlap each other). As you play the effect back, the reflection increases over time.

Sources: http://www.maclife.com/article/howtos/a … creencasts