How is the iPhoto Library organized

Question

I apologize if this topic has been covered - point me to earlier discussions if appropriate.
I'm curious about the filing scheme in the iPhoto Library. When I look in the Finer in the Library I see that there are folders by year, and within those folders are subfolders, and sometime sub-subfolders, identified (named) with numbers (eg 8, 12,15). The subfolder numbers do not begin with 1, and thought sequential there are gaps in the numbering. How does iPhoto decide what folders to create and what to put in each folder? There doesn't seem to be much rationale?
Also, one of the folders in each year (buried down a few layers) is Orginals - which seems to have the original versions of images I modified. How to I access those Orginals within the iPhoto (v 2) program?
Thanks much everyone.
Jim

Answer 1

Hi, Jim. A correction to my prior post: Pictures aren't filed by the date on which they were imported; they're filed by their "last modified" dates.
Brie will correct me if I'm wrong about this, but I don't think there's any simple way to determine within iPhoto (v. 4 or earlier, anyway — I've never used any later version) whether an image has been altered or not. You have to look into the Finder file hierarchy to determine that, and it isn't very easy. Every image you've edited in iPhoto remains right where iPhoto put it initially, but as soon as you edit it, a *copy of the original, unedited image* is stored in an Originals folder in the same location as the edited image. So the way to figure out which images have been edited is to look in the Originals folder within the day-month-year folder to which a given group of pictures was imported, and compare the filenames of the images stored within the Originals folder with the filenames of those stored outside it, in the same enclosing Day folder. The images for which there are no copies within the Originals folder are unaltered from when they were first imported into iPhoto. The ones for which there are copies in the Originals folder have been altered, and the altered versions of those pictures are the ones outside that folder. That's all clear enough. What's much more confusing is that the originals of pictures you haven't altered are NOT in the Originals folder — they're loose outside it.
If you aren't thoroughly bewildered yet, I can keep working on you. ;o) But in sum, iPhoto's storage habits are strange and arcane enough that most people never bother trying to understand them, and even those who study of them ultimately find it doesn't do them much good. iPhoto is completely inflexible about these arrangements, so if you want your pictures stored in a folder hierarchy you can readily understand and manipulate yourself, iPhoto is the wrong application for you to be using. I have eight separate iPhoto Libraries for different groups of pictures, and of the roughly 100,000 pictures I've stored in all, only a third are in any of those libraries. The rest are filed according to my own needs and preferences, in Finder folder hierarchies of my own design, and I manage them using other applications. iPhoto is a convenient tool for managing my less important images.