You can export your PowerPoint presentation as a video. Choose File, Export, Create a Video. Then you can choose the quality or size of the video. Ranked from low to high, you can export as:
- Standard (480p): smallest file size and lowest quality (852 pixels width by 480 pixels height)
- HD (720p): medium file size, and moderate-quality (1280 pixels width by 720 pixels height)
- Full HD (1080p): large file size, and full high quality (1920 pixels width by 1080 pixels height)
- Ultra HD (4K): largest file size, and ultra-high quality (3840 pixels width by 2160 pixels height)
So our advice it to save export this presentation as a 4K video for 2 reasons.
Number of Pixels
With text boxes and tables etc on a high definition slide, it would make sense because PowerPoint can resize those shapes as high-quality shapes in the 4K resolution. But images that you placed on a slide in lower-than-4K resolution cannot be enlarged. PowerPoint can here not guess what pixels to add.
When you look at the first line of pixels of an image there, we are looking at exactly 1920 different pixels. Now, next to that, look at the first line on pixels of the first frame of a video file. That line would contain 3840 pixels. This means that we have two times more pixels in the video pixel line.
When you export this 1920×1080 picture to a 3840×2160 video, then PowerPoint would have to add pixels and where would they come from? Every pixel of the original picture would be simply placed two times on your video pixel line. PowerPoint can absolutely not add new pixels other than duplicating the existing ones.
So because of this reason, we would not suggest exporting to a 4K because it would absolutely not result to better or more quality.
Video File Size
The file size of a PowerPoint presentation is very small. Use a new presentation with one slide with e.g. Four text boxes with some dummy text on it. Save the file and the pptx file will be very small some 35 kb.
When you change the advance slide option from ‘on mouse click’ to ‘after 10 seconds’ and save again, then the file size remains the same. So even when your slideshow is showing for a longer time, the file size of a PowerPoint presentation remains the same.
Let’s export the presentation now as a 4K video. File, Export, Create a Video, select the 4K video option and create the video. The file size will be 10 times more. A bit more than 300 Kb with our simple test presentation. Note that the duration of the slide or slide show was set to 10 seconds. When we change the duration now to 100 seconds (10 times more) and create the video again, then the file size of the new movie would be 2930 Kb. When we save this same presentation as a full HD movie, then the file size is only 830 Kb.
This testing is to show you have large an exported video file can become. So to come back to the original question, when we are not getting a higher quality (because of the lower image resolution), the final file size is another reason not to choose for 4K video exports in this case. It would only take up more disk space, and not increase the quality of the content.
In general a 4K video will result in very high-quality output, but here, with the original full HD images in the presentation, it would make no sense to export the presentation or slide show as 4K movie. Two reasons: PowerPoint can only guess the extra pixels, and the second reason is the unneeded larger size of the video file.