How can I transfer all my photos from mb aperture file to a external hdd?

From within Aperture:

File Menu--> Relocate Masters.

More complete explanation:

First make a Vault to an external drive as backup.

Then from within Aperture:

File Menu--> Relocate Masters.

Next back up the drive that the Masters were relocated to, because now you have a Referenced Masters Library so Masters are backed up (once) separately from the Library Vault backups.

In the future back up originals (once) on external drives prior to import into Aperture or any other images app. I cannot overstate how important that is, and various manuals, texts, etc. present workflows that skip that critical step. Also back up the Aperture Library using Aperture's Vaults, which are designed for that purpose.

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A complete Referenced-Masters workflow follows. Note that for image security reasons Aperture is not involved until the end of the process:

• Create a folder ("abc") for the incoming images. Easiest is to create the folder on the external hard drive where the Masters will permanently live, but Referenced Masters can be temporarily on the laptop's internal drive, then moved later as described above. I initially put Masters referenced on my MBP internal drive, then after backup and editing I use File Menu--> Relocate Masters to move the Masters to a permanent external drive location.

• Connect a card reader with the camera card in it. The camera card should show on the desktop. If it does not show, restart the Mac with the reader and card still plugged in. You can of course use the camera directly in this step, but I do not recommend it. Obviously cameras like the iPad2 do require direct camera-to-computer uploading.

• Drag the contents of the card's image folder(s) to the abc folder that you previously created on the hard drive.

• Review the abc folder contents to be sure they all copied properly.

• Software-eject the camera card.

• Physically disconnect the camera card reader from the Mac. This step is important to help avoid all-too-common human error.

• Again review the abc folder contents to be sure they are indeed all there (because stuff happens sometimes...).

• Back up the abc folder contents on to another drive.

• Review the files on the backup to be sure they all copied properly.

• At any time after but not before the previous step you can reformat the camera card in-camera. Do not delete images on the card using the computer.

• Start Aperture.

• Import the images from folder abc into Aperture, selecting "Store Files: In their current location" on the right-hand side of the import window (important!).

HTH

-Allen Wicks