Whenever you need to quickly get information about a photo in your Aperture library — the camera settings used, the file size, even the caption you’ve added to the photo — there’s a lightning-fast way to view the information, without having to open the Metadata Inspector or turn on metadata overlays. Use Image Tooltips.

1. Use your mouse to point to any image in your library — either a thumbnail in the Browser or a full image in the Viewer.
2. Press the T key to display Image Tooltips. This floating panel, anchored to your mouse pointer, gives you on-the-fly access to the basic information about the photo you’re pointing to, so you can see camera settings, keywords, ratings, and so on. If you point to another image, Image Tooltips will instantly update to reflect the data for the next image. There’s no need to actually select other photos; you can just move the mouse pointer over any number of thumbnails or images in the Viewer, and Image Tooltips will continually update with the data for each photo. When you’re done, press T again to hide Image Tooltips.