I had an oops moment, accidently formatting my new sandisk cfast 64GB before transferring the CR2 files to my computer. I tried running several image recovery programs including RescuePro and Image Rescue 5. Even though the Sandisk Extreme Pro 2.0 Card Reader was visible in both windows 10 Explorer and OS X Yosemite Finder it was not recognized in any of the image recovery programs I tried. What to do?
Fortunately my son was visiting and he came up with this solution which involves making a disk image of the cfast card on the macbook desktop.
The first step is to find out the cfast disk identifier in terminal using
The identifier was disk2 for the cfast disk. Next, create an image of the cfast drive "disk2" on the desktop called "recover.img"
sudo dd if=/dev/disk2 of=~/Desktop/recover.img bs=1m
Finally, I reran Image Rescue 5, executing File > Add Card File to Scan ... and selected "recover.img".