There might be some instances where you want to access your photos but do not want to use iPhoto to do so. This could be for several reasons. One is that you have a lot of apps open and you don’t want to add on to the burden by opening another one. Another is that while iPhoto does have an export function, it might be easier to just copy the file to a flash drive or disk. And if the photo you want is not in your albums, you might end up through scrolling to a lot of photos before you find that particular one.
Before accessing your photos without iPhoto, you should have an inkling when your photo was taken. That is because iPhoto organizes the folders by date. A word of warning: when opening the iPhoto library, do not delete, add to or modify the folders because it might corrupt your iPhoto library.
To access your iPhoto library launch a Finder window from the Dock. Scroll down your Home Folder until you reach Photos. Drop down the arrow or double click to go to the Pictures Folder. Locate the iPhoto Library file. It has an icon similar to the iPhoto icon on the dock. Press control+click or alternatively two-finger tap the file.
Select Show Package Contents and the library will open to show its files. Open the Data.noindex folder. The folder will show all your photos in various folders according to their dates.
This is also a great way to access the iPhoto library when the library file is corrupt (maybe because of an update).