[Video] How to make the ‘Magnifying Glass Map’ effect in Screenflow

image-how to make the magnifying glass effect using screenflowIn a previous post (ref: How to Make the Magnifying Glass Map Effect Using Camtasia) I shared the tutorial of a colleague who made this animation using the green screen (“remove a color”) feature in Camtasia Studio v 8.1.  (Just a quick note: the “remove a color” feature wasn’t available in Camtasia Studio prior to version 8.1.)

Let’s Use Screenflow This Time

In this post, I wanted to share a few more details about making the effect work — and this time let’s use Screenflow (for Macintosh) to pull off the effect.


The gist of the effect is to use screencasting software to show a metaphor–in this case, a magnifying glass–move across a map.  As it does so, magnified areas of the map appear wherever the magnifying glass traverses the map.  In addition to applying this effect when screencasting map sequences, the effect can also work well for other screencasting projects in, say, biology and anatomy when tracing genomic sections.  In which case, perhaps a microscope metaphor might work.  Or, you could also apply it to financial scenarios where you might want to “drill-into” a spreadsheet cell and examine the underlying calculations.

The range of scenarios is obviously limitless.  The main thing is to use editing software that will allow for:

  • Chroma key-type effects (a.k.a., green screen or “remove a color”)
  • Multiple tracks in the editing timeline
  • And keyframe animations


0:15 The end-state of the magnifying glass effect we’re shooting for.

0:40 You have to make it in two passes. The first pass is to produce a reference video with a colored shape that you’ll later “punch a hole” through.

0:55 The second pass is to use the reference video with the colored shape as the starting point for a new Screenflow project. Then, “punch a hole” through the colored shape using the chroma key video effect in Screenflow.

1:15 The third step is to overlay the magnifying glass stock image in order to complete the metaphor.

1:30 Here I launch Screenflow to start creating the reference video. Here we used a map graphic snapped from Google Maps. Then, on top of that, we add a red-filled circle.

2:45 Animate the red-filled circle to trace out the path on the underlying map that you want your magnifying glass to trace.

3:15 A question for the Screenflow Product Managers at Telestream! (What’s the deal about not easily being able to create a color-filled circle?)

5:30 Export the animation to create the reference video.

5:50 Create a new Screenflow project and import the reference movie.

6:25 Use the Screenflow Chroma Key video filter to punch a hole in the red-filled circle in the reference movie.

7:15 A word you need to know about the “tolerance” setting in the Chroma Key Filter. Initially, Screenflow will attempt to make a transparency on all similarly colored objects on your screen — even ones you don’t intend. The Tolerance parameter in the Chroma Key filter can help you adjust this!

8:20 Add the magnified graphic to your timeline and underneath the reference movie. This will then be revealed through the “hole” in the reference movie above it.

9:45 You now need to animate the underlying (magnified) graphic on track 1 in order to sync it up with the “hole” in the reference movie on track 2.

10:55 New term: Definition of T.L.A.R.?

12:05 Now we complete the metaphor with the magnifying glass graphic. You can find these graphics from cost-effective royalty free media sites like Fotolia or Presentermedia.

13:30 A little tip about the differences between PNG and JPG files. And what’s the preferred file format if you want transparency included.

14:10 Importing, aligning and animating the magnifying glass image in order to sync it up with the “hole” in the top image and the magnified map underneath.

16:45 The completed magnifying glass effect is fully rendered.

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