IPad – How to change photo upload size in Dropbox iPad app

Purpose of this folder:

When iTunes synchronizes photos to your iPod, it actually converts and resizes them into 16-bit bitmaps in resolutions appropriate for the iPod. It stores the converted photos in the iPod Photo Cache folder before transferring them to the iPod. This basically allows iTunes to quickly add/remove photos from your iPod without having to reconvert them every time. If you remove a photo album/folder from your iPod (by unchecking the box in iTunes preferences), it will still leave the pictures in the cache in case you want to add them again in the future.

Possible workaround:

Move the iPod Photo Cache folder to the location of your choice, and make an alias (shortcut) to the folder in its new location. Place the alias in the folder where the iPod Photo Cache originally was (usually in the Pictures folder) and make sure the alias is named "iPod Photo Cache". When iTunes looks for the iPod Photo Cache folder in the Pictures folder, it will instead find the alias, directing it to the new location.

You didn't specify the OS of the computer but on Windows that would be a junction point.

You could probably do a database repair. Hold down command+alt+shift and click on iPhoto's icon to start it. You should be presented with a window and multiple commands. The rebuild database and rebuild thumbnails options should help.

I know that when you sync photos to an iOS device, photos are scaled downed then synced to the device, and these scaled down photos are stored within iPhoto's library. But it wouldn't explain the library doubling, though... strange.

Make sure you have a backup of the library before doing this operation, you never know...