Urgent help needed can you recover data from an SD Card formatted in 5D3

Flyspur wrote in post #17511840
I had success recovering a load of video files and jpg's from a formatted micro SD card using free software called Recuva from Piriform. A low level format may be a problem, but it might be worth a try.

That is exactly what I recommended early in this thread. Then I tried it. Recuva works just fine with a regular format. If I check the "LOW LEVEL" box, Recuva finds nothing. Then it offers to do sector scan (or whatever Piriform calls it) that takes 30 minutes. It found nothing to recover that time either. Bottom line: Recuva does not work with low-level formatting.

Bottom line, NOTHING WILL WORK with low level formatting. You literally initiate a full wipe of the card and reset all the bits to 0, as others have mentioned.

someone0 wrote in post #17512458
Sorry to have post this a little late, but I just saw this. I don't believe this is such thing as low-level format on yhe sd card, but what it said inside the camera about low level format ia more like a full format. the different between quick vs full format is that a quick format will erase the file structure and making it look like there is nothing on it while leaving the rest of the content alone. Think of it as ripping the table of contents pages out of the book and replace them w/ empty page instead. A full format will not only make a clean file structure but zero all the storage area as well. In term of book analogy it s like replacing all the pages in the book with empty one. Generally this is very bad for flash storage and not recommended. You will know if you make a full format when it take you minutes to wipe the card instead of a few seconds. I do have some tools as well, but I'm not at home now. My recommendation is that when you need to do recovery on the card, ideally is to make an image backup of the card first. As that if one recovery tool unable to recover it won't messed up the card so that the next tool you try can still recover it. Making an image is a technical term refer to the process of cloning a storage media. This is more like scanning all the pages in the book into a pdf even though the table of content if ripped. recovering tool would be looking at all the pages and then remake the table of content based on reading the contents of the book. So if you scan all the pages first before trying to remake table of content then even if you messed something up you can still reprint the rest of the book and retry again. Hope thisj help. When I get home I'll take a look at my collection of tools and post again.

Canon cameras only take a few additional seconds to do low level formats on SD cards. There have also been people who have reported slower and slower write times that are rectified by low level formats on SD memory, I think the reason is that SD cards will only flip the bits that are necessary, and if you have a card that has a jumble of 1s and 0s, it has to flip both the 1s to 0s and the 0s to 1s, whereas with a low level format it only has to flip the 0s to 1s and the 0s would just stay 0s for the rest of the data (I could be wrong on this, I am not an expert on how SD cards write their data).

Keyan wrote in post #17515248
Canon cameras only take a few additional seconds to do low level formats on SD cards. There have also been people who have reported slower and slower write times that are rectified by low level formats on SD memory, I think the reason is that SD cards will only flip the bits that are necessary, and if you have a card that has a jumble of 1s and 0s, it has to flip both the 1s to 0s and the 0s to 1s, whereas with a low level format it only has to flip the 0s to 1s and the 0s would just stay 0s for the rest of the data (I could be wrong on this, I am not an expert on how SD cards write their data).

I do not think that is the case I mean most SD card, especially the fast one, the read times are faster then write but not by large magnitude. Aasuming your thought is correct, which meana camera has to read before write every time during the low-level, otherwise it would not knsow which sector has 0 or 1. I would think this would even be slower than faster. Generally I almost never format my card while working. I would shoot then take the card to the pc read it and leave it in the camera. I only format card the night before I shoot next time. This would serve me well as a backup also. If something went wrong on my PC I would still have images on the card and have to re-process again. There is nothing to be gain by format the card too early. Also, medias are relatively cheap now. I have like fives 64GB sitting in my bags alone and not counting all the other 32GB and 16GB cards.

I don't think the camera is aware of the mapping of the sectors on the card, the card's onboard controller chip manages that, the camera just requests a file read or write.

ex:

Quick formatted card, existing data byte : 01100110
New data to be written: 10011001
The card's controller would have to flip all 8 bits to new values.

Low level formatted card, existing data byte 00000000
New data: 10011001
The card only needs to flip 4 bits to 1s.

It is possible that the card will still overwrite any values that were present anyway, which would lead to no difference between the two. I just think it odd that some users have reported pretty significant performance decreases and a low level format cleans it up. I also think it is interesting that low level formatting is only available on SD cards, it doesn't seem that Canon cameras will low level format a CF card.

Read/Write differences are the result of a number of factors and many of the numbers posted by manufacturers are ideal circumstances.

My understanding is that the controller on the card attempts to write to each location on the card evenly, starting at the beginning of the card and working through the to the end before starting at the beginning again. This is because there is a theoretical maximum number of times that each location can be written to.
The standard format only wipes the directory and the card controller is still able to keep track of the write state of the locations on the card. Of course if individual files are deleted their locations are available to write to at a later date when the controller is looking for somewhere to put a file, it will use these locations leading to file fragmentation and slower writes.
If the card is low level formatted all locations are purged removing fragmentation and also making files on solid state devices unrecoverable.
There is still the possibility of recovering files from magnetic media after a low level format but only with specialist hardware.

Submariner wrote in post #17510800
Sods law this time the first for maybe 20 shoots I didn't!.

I have lots of 32 GB SD cards and one 16 GB CF. So knowing it was a long shoot Imthought it would run over 16 Gb and then its a pain with duplicate file number when the cf card runs out!

Learnt my lesson eh!
I should go and buy a 32 GB CF card to run a clean duplicarion, but am so loathe to invest in that grossly overpriced, jaded technology. - especially with those ludicrouis tiny pins.

Oh for the day when Canon bring out dual SD slots.

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