I caption all of my "keep" images: those with one star or more. That might seem like a huge amount of unnecessary work, but it is not. I caption tens, sometimes hundreds, at a time. And it is valuable. Since I only keyword the "show" and "brag" images (two or three stars), the captions offer a method of finding images and tying large groups of non-keyworded images to keyworded ones.

To start captioning I get rid of everything except the grid. Option command B maximizes the grid browser and W gets rid of the project pane if it is there.

Then I filter down to one star and select broad swaths of images by shift-clicking, command-clicking or just dragging boxes. Command-dragging boxes works too, and by a combination of command-clicking and shift-clicking I can quickly select all kinds of combinations of images.

I start by captioning the broadest set. Having select the images that the caption will be added to I hit command shift B to bring up the batch change dialog and select Caption Only from the Add Metadata From pop-up. This gets rid of extraneous clutter on the dialog. Then I type in the caption and hit Enter on the numeric keypad. That saves clicking the OK button. Return on the main keyboard adds a line return in the caption box.

In the example above I captioned hundreds of images with "A month in Europe". Next I make smaller selections and caption those. I am looking to capture information that would not be contained in the other metadata, so I am not going to caption by country or by date, or by something that is useless for finding things like "Week 3". Examples of useful captions are "Rhone Valley rail trip", "Car breakdown in the Italian alps", "North of the Arctic circle".

Since I leave the Append button selected in the Batch Change dialog, each caption gets added to the ones already there and separated with a comma. I always caption once, often twice, but have not needed to caption three times yet. That could happen if, for instance, I attended a memorable event inside the Arctic circle on the month-long European trip, and wanted to caption those images "Vegard's costume party".

To take a quick look at a thumbnail while captioning I can hit V to bring back the viewer and V to remove it again. Setting the Primary Only view mode (option R) from the View selection allows me to look at just the one image I have selected. As an alternative to V, I can hit F to go into full-screen mode and F to go back again.