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I protected (or locked around 10) pictures on my Nikon D750 with the intention of deleting other files off my memory card to continue to use the card. However, instead of doing that, I accidentally formatted the card.

And then, I took more pictures (big no no, I am aware...). The first set of pictures were on the memory card along with 900 other pictures. I imported all the images I needed for clients but left the original 10 images (they are personal). They are baby pictures. After formatting, I took about 200 more pictures at my daughter's field trip ice skating.

I have run three different card recovery programs and they all bring up the same stuff - the ice skating pictures (which are imported, but still on the card); and about 80% of the client pictures (which are imported prior to the card being formatted); but about 20% of the client pictures and the missing 10 pictures (which were the first images taken on the card the first time) never come up.

Is there a limit to the amount of pictures that the recovery programs will find? Does the fact that they weren't originally imported or the fact that I protected them before formatting the card making them impossible to find? Or, are they just gone?

Is there a super powerful recovery program you recommend?

I would retake them but it's impossible now and they were really really cute. I'd love to be able to find them

enter image description here

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    Possible duplicate of How can I recover deleted photos from an SD Card? – Philip Kendall Nov 25 '16 at 22:15
  • Testdisk and Photorec from cgsecurity.org are probably most powerful, but it sounds 90% likely that they'll recover the same images as the other software you tried. Testdisk can sometimes recover reformatted/lost partitions or deleted files, but photorec is more likely to work in this case especially after a partial overwrite or corruption as it finds the photos themselves. – thomasrutter Oct 23 '17 at 2:24
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For the general question of recovering photos from a formatted card, see this question. Personally I have the best results with Photo Rescue. I am not affiliated with that program but when I lost some important photos (more than once sadly), that is the software which gave best results. Some photos will never be recoverable since the data has been overwritten.

Protecting images does not do anything more than set the Read-Only flag on the file which prevents deletion but not formatting. Recovery success does not change because of this.

Importing images has no impact either since it really does not write to the card and recovery programs only read the card, they do not use any external files for comparison. Since you haven't changed input, the software cannot act differently while recovering images,

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Data recovery programs have most success with data that has not been overwritten. The areas where the data is stored gets marked as free space, but in reality the data is still there until it is overwritten. Since none of the three data recovery programs have managed to restore the data you are hoping to find, this indicates that the data has been overwritten.

Think of it a little like a blackboard. Data is not wiped off the board, areas are just marked as "available for overwriting". As long as you carry out the recovery process before the data is wiped off and overwritten, things are reasonably straightforward and successful. I fear the data you want to recover has been "wiped off and overwritten" with your ice skating photos. Data does not hang around indefinitely waiting to be recovered. The physical card has physical storage limits, just like the blackboard.

Does the fact that [...] I protected them before formatting the card making [sic] them impossible to find?

The fact that you "protected" some files is irrelevant. It's important to be clear that the process of formatting the card pays no attention to "protected" files; formatting is the same whether there are protected files present or not. (As stated in another answer, these files are not really protected at all; they are just marked as read-only to avoid deletion in the standard sense.) Data recovery just finds data; it has equal success whether a lost file had been marked as protected or not.

  • While it is possible to recover data that has been overwritten on a physical hard drive with a spinning magnetic disc, it's near impossible to do the same thing with solid state memory - even if you have access to near limitless resources and classified recovery methods such as those used by the NSA. – Michael C Nov 27 '16 at 2:05
  • It's also near-impossible with modern spinning media. All of the lore around that is basically 30 years out of date. Realistically speaking, you overwrite it, it's gone. – mattdm Nov 27 '16 at 22:56
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    So, I would replace "have most success with" with "can only recover" – mattdm Nov 28 '16 at 12:15
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It sounds like the images you really, really want are some of the ones that were overwritten by the subsequent images you took using the card. At this point it looks like there isn't much of anything left to try that you haven't already done. They're gone.

Is there a limit to the amount of pictures that the recovery programs will find?

Yes. You'll never recover more data than the total capacity of the card. If, over the course of several formats/erasures, you've written 1100 total images to a card that can only hold 900 images that size, then 200 of the most recent images have been written in the same space that was once used for 200 of the images written before you reformatted the card.

One thing you can do is check the total size of all of the files you recovered from the card including the files that had not yet been erased. It's probably going to be pretty close to the total storage space on the card. If that is the case then it is almost certain the files you can't recover were overwritten with newer files. For a more indepth discussion of how this works please see the end of this answer.

I had a similar experience one time when I forgot to put a few extra memory cards in my pocket before a shoot that required parking a good ways away from what I was shooting. I was going to be in a crowd and so left most of my gear in the trunk of my car. About halfway through the shoot I realized I had not formatted the memory card in my camera to erase all of the images from a previous shoot that were still on the card, even though I had copied the earlier images to my computer, done all of the edits, and backed everything up. Naturally it was one of my smaller backup cards that I had used at the end of the previous shoot after filling the larger primary cards (which were half a mile away in my backpack in the trunk of my car on the other side of an entrance/exit gate).

I protected all of the images I had taken that night, erased the rest of the images, and continued to shoot.

I was taking a lot of images because it was at a carnival at night and even though I had the camera on a tripod there were a lot of non-keepers due to people walking in front of the camera during a long exposure, the flashing lights on rides and other attractions only being lit for a few of the colors or only on parts of the ride during the exposure, as well as bracketing exposure and WB for many of the shots, etc. When I began getting tight on space again I decided to go through my images and unprotect the obvious throwaways and then I erased all but the protected images again.

I then shot a few more images and started reviewing them in reverse sequence. When I got to the first of the shots I taken since the second erase operation the next image back was the last image I had shot before the first erase operation.

It was then that I realized I had forgotten to protect the images I had taken between the first and second times I erased all but the protected images in the card! NOOOOooooo! Some of the best images of the night were in that section. I couldn't go back and retake most of them because the carnival was winding down, most of the people had left, and many of the rides were shutting down as they prepared to close.

I got home and immediately copied the unerased images on the card to my computer. I then began a data recovery operation. Since the CF card in question was a Transcend branded card I started with Transcend's RecoveRx application. It found 509 erased images on the card. Most of those were from the two previous sessions I shot using that card prior to the carnival. It did recover 54 of the 82 raw files I had accidently deleted.

Roller coaster

Kids
(Some kids from a local high school who recognized me from work I had done at their school and begged me to take their picture. Not one of the better compositions that evening but I would have hated to have lost it and not been able to send it to them.)

I then turned to Piriform's Recova using settings specifically designed to recover image files. It identified all 82 of the accidentally deleted files as TIFF files (It always sees .cr2 files as TIFFs). I copied them to my computer and changed the file extensions to .cr2. However, only the same 54 recovered by RecoveRx could be opened by any of my image applications that can open Canon .cr2 files. I can open the other 28 in notepad and get a huge document of gibberish characters, but I have found no way to open them with any type of image recovery software.

My theory is that they were somehow listed in a file directory that was still readable but that the locations those listings pointed to had been overwritten with the 27 images that I shot after the second erase operation. Because the raw files are all slightly different sizes none of the headers of the new images lined up with where the old directory said each of the headers for the old images were located and that is why I can not open them. Should I find a photo application that could open at least fragments of the files I'm pretty sure I would be looking mostly at information from the 27 images I took last and for which I already have perfectly good copies scrambled in with very small fragments of the images they overwrote.


The way flash memory cards (and USB drives) work is that the memory controller on the card assigns different areas of the card for specific directory locations each time the card is formatted. They do this for what is known as load balancing.

Flash memory has a limited number of write cycles it can tolerate before it fails. The number of write cycles each bit on a flash memory card can handle before it fails is very large but it will eventually wear out. So the controller tries to ensure that each storage location of the entire card is written to roughly the same number of times over the life of the card. What this means is that even after you format the card the controller will continue using parts of the card that have not yet been written to until each storage location on the entire card has been written to before it will go back and begin using the locations that have already been used.

That's good for recovery because it means not much is overwritten until the entire card has been written to once. But then it's going to go back and use the very beginning again if that space is showing as empty. When you delete a file normally the space that file used is marked as empty but the state of each bit in that space is not altered. When you format a card pretty much all of the regular storage space on the card is marked as empty and available for use.

Formatting regularly helps the memory controller on the card do a better job of wear leveling. It also allows for better card performance by increasing the likelihood of sequential write operations. If you leave the same file on half the card and repeatedly write files to the other half, erase them, and rewrite other files then all of the wear is going to go to only half the card and the life expectancy of the card before half of it fails will be shorter!

What this also means is that if you have kept a few of the same images on the card over several erase/rewrite operations that each used an appreciable percentage of the rest of the card then the first space to be used after a format will very likely be the space that contained those images that were not erased and rewritten each time most of the card was reused.

  • I don't think the wear leveling in SD cards cares about formatting. It works below the file system, not with it. – mattdm Nov 28 '16 at 12:18
  • Yeah, but if one area has held the same data since the card was new when the rest of the card has been overwritten several times it will have lower write totals and will thus be first up when it is showing "empty". – Michael C Nov 28 '16 at 13:18
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    Oh, yes, if you leave files on there. Formatting won't be significantly different from "delete all", though. – mattdm Nov 28 '16 at 13:22
  • Except that when you format pretty much everything that is usable as regular storage is marked "empty". The sectors with the lowest number of writes will be used first. Delete all from most cameras firmware will save folder structures, it will just show the space where the content of those folder was contained as "empty". This could lead to minor breaks in sequential writing and if that data was subsequently accidentally deleted with a full format it might be harder to recover. – Michael C Nov 28 '16 at 13:27

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