Surprising though it sounds, while Lightroom and Photoshop each make it easy to put visible watermarks on image files, neither makes it easy to label those files with filenames. Short of coding a script to do it in Photoshop, the best method—cumbersome as it may be—is to use Lightroom’s Slideshow module to label images visually with their file names.
To start, navigate in Lightroom’s Library module to the folder containing the images you would like to label, then switch to the Slideshow module. From here, click the ABC button immediately below the preview window in order to add text to the slide. An option then pops up offering a blank space to enter custom text for the slide. Instead, click on the words “Custom Text” and a dropdown menu will appear with options including Caption, Date, Exposure and other useful information. Click Filename and Lightroom will place the filename on the image. Click the corner of the text box to resize it, or click anywhere on the filename to relocate the text box to any position you like.
Clicking on the filename will also highlight text options in the Slideshow panel to the right of the screen, including color, opacity, font and typeface, as well as options for adding a drop-shadow. This shadow is especially helpful for ensuring the filename will remain readable over any portion of the image (no matter how similar to the selected font color, and if you’re applying names to several files that’s likely to come in quite handy.
Scroll up to the top of the Options panel and you’ll find other features that are also likely to be useful. If your image isn’t a horizontal 4×6 it won’t fill the entire frame of the slide unless you check the Zoom to Fill Frame checkbox at the top of the panel. This will necessitate slight cropping, however, so if you need to see every bit of the full image area uncropped, uncheck this box. You’ll then see portions of the slide’s background color at the top or sides (depending on whether your shot is too long or wide), which you may or may not appreciate.
If you want to see the full frame but don’t want to see any background, the best solution is, unfortunately, a makeshift workaround. Create the slides with the background visible, then create an action in Photoshop in order to automate the cropping of the slides (which you will output momentarily as JPEGs) so that you can batch crop the images to eliminate those edges of the background. (If your images are cropped in multiple different proportions, the most effective approach is to sort them according to those proportions and correct them in separate batches.) Most of the remaining controls in the Slideshow module are for tweaking the specifications of an actual slideshow, so they have little or no bearing on the images you’re working with since you’ll be exporting them as individual JPEG files.
To do that, choose Export JPEG Slideshow from the Slideshow menu at the top of the screen. In the popup window that appears, select the location in which the files should be saved, as well as the image quality and dimensions of the JPEG files. Click Export and Lightroom will output all of the images as JPEG files in your chosen destination.
If you have cropping to do—for vertical images, for instance—simply open an image in Photoshop and click Actions under the Window menu to open the Actions palette. Here, click the New Action icon, name the action and then click the red button to start recording. From here, every action performed on the image will be recorded for playback at a later date. Simply choose the crop tool and enter presets that match the proportion of your desired image—4×6 vertical, in the example shown here.
Click to crop the image, and then click the stop button on the Actions palette to cease recording. Close the image, and then choose File>Automate>Batch to perform this same crop on all of the images in your designated folder. It may not be an especially sleek approach, but it’s still the simplest way to use Lightroom and Photoshop to create images labeled with their filenames on the image.