Why you should rename your files.
1) Our photos straight out of camera usually have four digits in the file name, from 0001 to 9999, then it cycles back to the first after reaching maximum. But photographers today shoot more than 10,000 pictures for the life of one camera, so there's potential for file naming conflict or accidental overwrite if images are lumped together in one folder. To avoid this possibility, you may want to rename your files.
2) It may also be useful and instructive if a photo's file name tells us something about the photo itself, maybe the place or event when that photo was taken, perhaps a date, or even a person's name aside from its unique identifier number. One look at the file name and you have an idea what the photo is all about when browsing in list view in the folder. Photos from the same shoot or event tend to group themselves together if you rename your files this way. They also arrange nicely, chronologically.
3) It is even more relevant for professional photographers. Wedding photographers, for example, may include a client's name or the date of the shoot in the file name. Food and product photographers may include the product name or company name.
4) Those who sell photographs in the stock photo market may also rename their files according to a system that suits their photo libraries. The aim here is to make the image files easy to find by web search engines like Google Image Search which looks at the names of images, the filename.
5) Even if you stick with your original file names, you might need a file renaming system when you output derivative copies from your originals.
HOW TO RENAME FILES?
The file renaming suggestions advanced by experienced users show filenames that look like this: ABC_150915_1234.DNG, where ABC are the photographer's initials, 150915 indicate the date of 2015 Sep 15, 1234 is the unique identifier number or counter for the file, and DNG is the filename extension. Instead of your initials, you may want to replace ABC with your own name as long as your name is not Rajaratnamurti, Supitayaporn, Dimaculangan, or some other long name so it may look like this: Tagle_150915_1234.DNG. You can rename your original files this way.
Another form for original file names could look like this: ClientName_150915_1234.DNG or simply ClientName_1234.DNG, where ClientName is the name of your wedding client or the name of the product you're shooting. This is applicable for wedding and advertising photographers. Just bear in mind that this file naming system is strictly tied to your client. What if you are going to use pictures from these shoots for another purpose and you're going to have to show your images to a new client? In that case, you are better off using your own name.
The file naming forms suggested above are useful for professional photographers and people who shoot a lot of photos. But you don't have to be pro to appreciate that these can also be applied to your own photographs if you want a logical and consistent way to organize your images.
HOW TO DO IT IN LIGHTROOM?
The File Renaming panel, Fig. 1, in Lightroom offers users a quick and easy way to rename original photo files. It is available at the import stage, or at the very first instance that you are bringing your images into Lightroom. In the import dialog box, placing a check mark on Rename Files enables file renaming, and you can then proceed to select one of Lightroom's file renaming templates from the drop-down menu, or make your own by clicking Edit at the bottom of the drop-down menu, Fig. 1-1. This calls up the Filename Template Editor, Fig. 2, where you can choose a Preset or customize your own way of naming files by selecting options from the list below for Image Name, Numbering, Additional, or Custom. Try clicking the drop-down arrow next to the word Dimension, under Additional, and you'll see a whole list of interesting ways by which you can rename your files.
FIG. 1. You can rename your files during import in Lightroom. Checking Rename Files enables file renaming, customize it by selecting one of the renaming templates.
FIG. 2. The Filename Template Editor is where you can customize your own file naming system. You can save your file naming system by clicking on the drop-down menu next to Preset above and Save Current Settings as New Preset.