Here is a guide on how to manage multiple Photos Libraries using macOS Sierra.
Photos on your Mac will open to its default library yet with Mac users delving into digital photography for work or more personal interests, having multiple options is an excellent resource.
Due to the fact that Photos is a library based system, you will be able to differentiate which library you want to access when opening Photos.
How to Use Multiple Photos Libraries on Mac
Here are the steps to set up a secondary library for Photos and switch back and forth.
How to Set Up Additional Photos Libraries
When you open Photos from your Dock, you customarily will see your own Library appear usually containing photos you’ve imported from hard drives or your iPhone. If you are planning on starting to get more into photography and want to import new images, you may not want to merge these photos together. This is where an additional library may come in handy.
In order to start a new Library in Photos, you must quit the app and then open it from the Dock while holding the Option Keyboard Key. When you hold this key down, it is essentially letting Photos know that you would like the Option of opening another Library.
A dialogue box will appear named Choose Library. This will reveal all of the recognizable Photos libraries that are currently on your machine or connected via an external source. This is an ideal situation for opening an older library and upgrading it from a backup so that it can be used with Photos.
If you are simply looking to create a new library, that option is below and will take you to a dropdown where you can name your library and choose its Finder Location. If you are using an external hard drive for photography work, ensure it is connected to the Mac and choose it from the Finder so your Library will save there accordingly.
Once you save this new library, Photos will open up and allow you to begin importing and editing photos just as you would normally.
How to Switch Photos Libraries
If you would like to go back and import and edit within your personal Photos library, fortunately you already know the steps! If you recall when we created a new library, we held the Option key upon starting the Photos app. This gave us the option to Choose Library and we opted to create a new one.
Now you should see your New Library included in this list, as well as your original library and any other libraries Photos is detecting. It will show you the last modified date which is usually a great indicator for identifying the library you are looking for. Click your library to open it and it will load all of your other content.
As mentioned, this is a great resource for people that work professionally in the Photos application and want to keep their work separate. This is also great for people that want to potentially be able to manage a smaller amount of files and split their libraries between other hard drives.
If you want to use a different library, just remember to quit and restart Photos with the Option key. Something to keep in mind however is Photos will continue opening the last used Library until you specify otherwise. So make sure you choose your internal library again after finishing your work on your secondary library.