Apple recently made the new Photos for OS X application available as a public beta, which means anyone who signs up for the Apple Beta Software Program can install it. But there’s a catch: you must install the entire OS X 10.10.3 Yosemite beta in order to run the application.
In my latest article for Lynda.com, I offer advice on how to do that smartly (hint: backups and test environments!), so you don’t disrupt your regular work or accidentally lose photos under pre-release software. Read it here: Photos for OS X App: The Smart Way to Install the Public Beta.