Answer:
To get a full-size preview of a file without opening it in Finder on your Mac, you can use Quick Look. Quick Look is a built-in feature of macOS that allows you to preview files without launching any specific application.
Here's how you can use Quick Look to get a full-size preview:
1. Open Finder by clicking on the Finder icon in the Dock or by pressing Command + Space and typing "Finder" in Spotlight.
2. Navigate to the folder where your presentation is located.
3. Select the file you want to preview by clicking on it once.
4. Once the file is selected, press the Spacebar on your keyboard, or you can also right-click on the file and select "Quick Look" from the context menu.
5. A Quick Look preview window will appear, showing you a full-size preview of the file's content. You can use the arrow keys on your keyboard to navigate through multiple files in the folder, and the Spacebar to close the Quick Look preview.
Quick Look supports various file types, including documents, images, videos, and more. It's a convenient way to quickly preview files without opening them in their respective applications, saving you time and allowing you to find the right file easily.
Please note that the other options mentioned, such as QuickTime Player, Spotlight, and Stacks, do not provide the same full-size preview functionality as Quick Look in Finder.