Best Image Size/Resolution for PPT
Ok, so I've been trying to do some research on this topic, and now I'm more confused than when I started. Some say the dpi of the image matters (72, 96, 150 have all been recommended). However, some (more reputable) sources have stated that the dpi doesn't matter for PowerPoint presentations (at least displayed/projected); rather, it's more about the pixel size of the image (recommended 1024 x 768 as a standard).
I also know the size of the image and the resolution are mathematically related. For example, an image that is 1200 pixels in width and 300 dpi is about 4 inches in width, whereas at 72 dpi, you're talking a little over 16 inches in width.
Here are my questions:
1. Let's say I start with an image that's huge, 3872 by 2592 at 300 dpi. I want to re-size this image to be full screen in my presentation when it's projected at 1024 x 768. If I re-size the 3872 to 1024, keeping the proportions the same, does the dpi matter for quality, file size, neither, or both?
2. How does setting default compression settings in PowerPoint affect any of this? For example, let's say in the above example I re-sized to 1024 in width, but I left the dpi alone at 300. Then, in PowerPoint, I used the compress images function to take it down to 150 dpi. Have I changed the size of the image now?
3. How does all of this impact working with Articulate products (versus displaying a PowerPoint presentation via a projector)? For example, I've seen the job aid where the image size is recommended at 720 x 540, with scaling options turned off. However, I personally don't like to lock the presentation, because as a learner, I like having control over the size, in case I want to see the text larger, etc.
4. I see the "slide show settings" in PPT can be used to set the presentation size to 1024 x 768 or various other choices. Is there a recommendation for setting the size for Articulate Presenter output?
I'm a little all over the place, sorry! If anyone has an answer or could point me to a good resource, I would much appreciate it!