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How can I avoid the hall-of-mirrors effect when sharing an application or screen in Bb Collaborate?


As of August 31, 2021, UofT will no longer license Bb Collaborate. Please see ACT's termination of Collaborate license memo for more details. We recommend reviewing our guide of currently available webinar tools for alternate options to host synchronous online sessions.

When you are sharing an application window or screen in Blackboard Collaborate Ultra, you might experience a hall-of-mirrors or tunnel view effect. This guide explains the steps you can take to avoid (or at least minimize) this effect.

1. Why does the hall-of-mirrors effect occur?

Bb Collaborate Ultra runs in a web browser rather than a stand-alone program. The hall-of-mirrors effect is normal and happens whenever you are sharing an application window or screen at the same time that you are looking at the screen with your active Bb Collaborate session.

Hall-of-mirrors effect when sharing an applciation or screen in Bb Collaborate Ultra

2. What steps can I take to avoid this effect?

Below are some steps you can take to avoid the hall-of-mirrors effect:

2.1. Use a second monitor to share your content

  1. If you have more than one monitor/screen, share the one that is not currently running your Collaborate session.

2.2. Move quickly to the application or screen you are sharing

  1. If you don't have a second monitor, switch quickly to the application or screen that you are sharing. This will ensure that the hall-of-mirrors effect is as brief as possible. Bb Collaborate Ultra  will continue running in its own browser tab.
  2. When you are ready to go back to the session, you can avoid the mirror effect by selecting “Stop Sharing” at the bottom of the screen before returning to the Collaborate Ultra room.  

2.3. Share your content as a file

If you are not sharing content that contains animations, audio or video, consider sharing your presentation as a file.  The file will be shared directly to the active session and will not result in a mirror effect.  You can share GIF, JPEG and PNG images, PDF files, or PowerPoint presentations of 60MB or lower. You can also upload multiple presentations (the total size allowed is 125 MB or lower for any single session)

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