Bill,
I was encouraged by your results and the Stellar Phoenix program. I downloaded the program onto my MAC. I'm not sure what to make of it, but my findings are different.
Test 1:
I used a 32 GB card that had recently been formatted (not low level) in my EOS M. That card should have had hundreds, if not thousands, of potentially recoverable images on it. I shot one RAW image on the card in the EOS M, and then performed a low level format in the camera. I scanned the card with Stellar Phoenix and it found absolutely nothing.
Test 2:
I used a 4 GB card (in the interest of saving scanning time) in my 70D. I performed a low level format, then shot 6 images (3 RAW and 3 JPG's). I performed another low level format, then scanned the card with Stellar Phoenix. It did not find any images.
Test 3:
I re-inserted that same card back into the 70D and shot the same series of 6 images. I then performed a standard format (not low level), and scanned the card again. This time, it found and recovered all six images.
So, based on these three tests, my results are uniform. A standard format leaves recoverable data on the card. But, a low level format completely deletes all data to a point that Stellar Phoenix cannot find or recover anything.
Obviously, these findings fly in the face of your own tests. I cannot explain the differences at this point. My three tests are not exhaustive by any means, but seem to be pointing in one direction. I may take some time tomorrow to try different cameras and different sequences to see if the results are ever different. I would love to find that Stellar Phoenix can be used successfully in at least some circumstances following a low level format, but I'm becoming skeptical.
