Webinar technology vendors use different methods to display PowerPoint slides to attendees. One strategy is screen sharing. Citrix GoToMeeting and GoToWebinar are probably the best known examples, along with just about every low-cost solution intended for collaborative web meetings.
Another strategy is conversion of each slide to a simple image (JPG, GIF, or PNG). The vendor may create a call to PowerPoint on your computer through an API and use the “Save As” functionality from within PowerPoint itself to generate the image files. Or they may implement their own conversion algorithm.
A common strategy used by vendors who rely on the Adobe Flash platform for operation is conversion of the slide presentation to a Flash movie upon upload (I’m simplifying for brevity). This can preserve animations and slide transitions. Adobe Connect has built their own proprietary converter. Several other vendors use conversion processing supplied by a third party (usually iSpring).
And then there are a couple of outliers like Cisco WebEx, which convert the PowerPoint slides to the vendor’s own proprietary internal format for display in the webinar.
Each approach has benefits and drawbacks. True screen sharing gives you display of the PowerPoint content exactly as PowerPoint shows it natively. You never have to worry about conversion errors. But you may be susceptible to internet lag delays when redrawing large portions of a slide, and smooth movement animations seldom display smoothly for attendees. When using screen share, I recommend staying with simple appear/disappear builds and not using transition effects between slides.
Converting slides to images creates a nice crisp display, but it usually limits the presentation to one or two fixed sizes rather than allowing infinite scaling to fit attendee screens. Unfortunately, saving slides as static images eliminates animation effects such as builds, movements, and slide transitions in your presentation.
Attempts to convert from PowerPoint to another format while preserving all the functionality of PowerPoint’s slideshow presentation mode within the webinar environment are the most ambitious. These usually allow for infinite scaling of the image for attendees. And most of the vendors have covered standard PowerPoint content pretty well. But I don’t think anybody can guarantee perfect reproduction.
Adobe Connect is extremely good at the game (Heck, they should be… They own Flash!). But I have written about Connect’s inability to reproduce certain fonts due to licensing issues, which can mess up your presentation visuals.
WebEx frustrates me occasionally with seemingly random misconversion of slide objects. Today I loaded a client’s PowerPoint in a room and an embedded table object on one slide showed up with half the text reversed or reading vertically rather than horizontally. On a previous webinar, we had a slide with three “call out boxes” (the shapes that look like cartoon dialog bubbles). Two of them displayed fine. The third one was mangled beyond recognition in the webinar.
I have become very familiar with conversion problems in iSpring as used by several of the Flash-based vendors. iSpring has a terrible time dealing with PowerPoint’s equation symbols. Putting a single equation symbol on a slide can distort all the other normal text around it. I have also found that PowerPoint Smart Art usually comes out fuzzy or improperly bolded after conversion. The same is often true for embedded objects such as tables or graphs. For safety, you may want to convert embedded objects to graphic images and reinsert them on your slides before upload.
As a presenter or host, you must NEVER assume that your PowerPoint slides will look or act correctly in your web conferencing console. Give yourself plenty of time to test, make workarounds, and test again before your live event. And if you are a vendor I have mentioned in this post… Keep working. Your customers spend a lot of time on their presentation content. They don’t appreciate having to redo it to satisfy your limitations.