accidentally deleted my masters, can I recover them

How did you delete them?

I assume you already checked, if they are still in the Trash? Your network drive needs to be mountes, to be able to see files from the network drive in your Trash.

If you cannot recover your original image files from the Trash, use your backup to recover them.

If a backup is not available, you could try to recover your image files from the external volume using recovery software, for example

Disk Drill: http://www.cleverfiles.com/

However, I have never used this program with a network volume, so I am not sure if it will work in your case.

Regards

Léonie

Without knowing the network drive in question it's not possible to give more than a general answer. But unfortunately the answer is most likely no.

Most (all) network drives do not implement a trash system like local OS X drives.

If you had realized the problem as soon as it had happened and immediately taken the drive off line it might have been possible to recover some or all of the files but if the drive was used after the deletion they are most likely gone.

Hopefully you have backups of the masters but given that you posted here asking this question I'd guess you don't.

However all is not lost. If you were maintaining previews in Aperture you can at least get those. And if you're preview quality setting was at the high end of the scale the images you get from them will be pretty good.

Because you can't export images that have no masters you will have to drag the previews out of Aperture. Just make sure you backup these images (and your library) because if something happens to these then you will really loose it all.

good luck