If you upload a SmartSlides slideshow to Facebook and it appears blurry, check the video quality setting of the video by following these steps:
Note that if your video quality is set to Auto, Facebook will optimize video quality so that your videos play without delays. This means that if you have a poor network connection that cannot load your video in HD quality fast enough, Facebook will show you videos in a lower quality so that they load quicker. If you are using the Auto quality setting and have a poor network connection, you may need to wait for the video to buffer before HD quality kicks in.
Helpful Tip: You can update the default video quality setting for your Facebook Account by going to Settings > Videos and updating the Video Default Quality option: