Why do I see so many DCIM folders when I view the iOS Camera Roll from my computer?

With iOS 8 Apple reorganized the way photos are stored. Later versions have followed and extended this approach. Rather than simply being files in a single folder, they are stored in a database that contains many folders, each with an obscure name known only to the database management application in iOS. In the past you could open the camera roll using Windows Explorer or Mac Finder and simply drag the photos to a location on your computer. The new structure makes it much more difficult to do this, but it provides a lot of benefits in terms of organization of photos, editing of photos, and syncing them to iCloud. So a new method is required to copy photos to your computer. Fortunately, it is no more difficult if you choose the right tools. Here are a selection of options. Note that NONE of these require you to know anything about DCIM folders.

If you have a Mac, don't use Finder (Actually, you can't with later versions of OS X). Instead use one of the following apps: Image Transfer, iPhoto or Aperture to view and import your pictures. See also this: What to expect when you import edited photos from your iPhone, iPad, or iPod to your Mac or PC - Apple Support

If you have Windows, don't use Windows Explorer. For XP use the Camera and Scanner Wizard, for Windows 7 and later, use Import pictures and videos. Here are the full instructions from Windows Help:

How do I get pictures from my camera to my computer?

Here's one common way to copy pictures and video clips from your digital camera to your computer:

1. Connect the camera to your computer by using the camera's USB cable.
2. Turn on the camera.
3. In the AutoPlay dialog box that appears, click Import pictures and videos using Windows.
4. (Optional) To tag the pictures, type a tag name in the Tag these pictures (optional) box.
5. By default, the folder name includes the date the pictures and videos are imported and the tag name.
6. Click Import.
7. A new window opens and shows the imported pictures and videos.

Other methods:

If you have iOS 8.3 or later, go to Settings/iCloud and turn on iCloud photos. Pictures will be transferred to iCloud as soon as they are taken. They can be viewed and managed by logging in to https://icloud.com. If you have a Mac you can also see them in the Photos app, and with Windows by installing iCloud for Windows on your computer (Download iCloud for Windows - Apple Support) For either Mac or Windows, use a 3rd party photo manager, such as Google Photos or Nikon ViewNX. Both are free. There are also tools that are not free but work well.

For yet another option, you can save them to dropbox or box.com.

To help further, Apple provides the following tech tip: Import photos and videos from your iPhone, iPad, or iPod touch to your Mac or Windows PC - Apple Support