Recover camera photos after SD card crash?

[handrawn]

good to know chris

I remember EaseUS free disk imaging, way back when....

a piece of string, but how long might it take to do this

disk forensics, I know, can take forever...

[Chris M]

good to know chris

I remember EaseUS free disk imaging, way back when....

a piece of string, but how long might it take to do this

disk forensics, I know, can take forever...

64GB running through a card reader/USB2 adaptor? 2 to 3 hours, maybe.

I run recovery's (data or Windows system) on a dedicated machine while I wander off to do other stuff, so I don't really time them. It also depends on how many data blocks need to be read multiple times...in other words, the more blocks that are damaged, the more passes the software needs to do to rebuild the individual blocks.

[handrawn]

thanks, I have no practical experience of doing this, assembling a PC is my limit

how discontiguous [fragmented] the blocks are is going to be a factor ?

both in terms of how long it takes and how much can actually be recovered ?

[Chris M]

thanks, I have no practical experience of doing this, assembling a PC is my limit

how discontiguous [fragmented] the blocks are is going to be a factor ?

both in terms of how long it takes and how much can actually be recovered ?

You're beginning to head into the why's and wherefores beyond my comfort zone. Basically, the software looks at corrupted or missing data blocks and compares it to nearby blocks. It then attempts to reconstruct said blocks. Then it looks for fragmented data. So, yes, the more damage, the longer it takes.

In theory, the more data there is to compare, the better the chances of recover. So an SD card full of photos in the same format is (in a perverse way) a good thing.

[handrawn]

sorry, I read a lot of theory once; I appreciate that yours is the practical approach

of course if the pointers are broken, because they all resided in the indexes [excuse if that is sloppy terminology], you cannot tell which blocks belong together [or in what order] other than by 'trial and error'

[Chris M]

I should add that if I was doing the job, I would run both, and if still failing, I would format the card as Windows wants to, and then do a re-run.