I have several slide shows on which I would like to change the object play time. All shows have been exported but I would like to change the play time to shorten the shows. How can i edit the shows to accomplish this?
You really need to load the project again and shorten the duration and re-burn it or re-export it.
It depends on what your slideshow consists of. If you are just using photos, then you can try right clicking on the first photo and selecting the option Display Duration.
Here you can reduce the duration of the photo and then click on Apply to All. This will then change every following photo in the slideshow to the new duration. The difficulty here is what other transitions and effects are in place. You will likely need to manually check that nothing has been messed up.
If your slideshow has a lot of video as well, then this is a little more tricky as you will have to manually edit it.
The problem is that once your slideshow is exported, then it is a video object and cannot simply be shortened. The duration needs to be changed during the editing process.