Memory card formating

hairy_moth wrote in post #14846767
This advice is bogus.

Erasing all pictures on the card will write to each of those sectors -- and a lot more.

You are broadcasting your ignorance. Sorry, no polite way to put that. Do a little reading about memory access and file allocation tables. You are so far off base that you don't even qualify as wrong.

A file allocation table (FAT) system is managed like a library card catalog. The only way to find out where the stuff you are looking for is, is to look it up in the card catalog. If you remove the card catalog, you have no way of knowing where anything in the library is. Same with a disk. All information about where your pictures are located is stored in the File Allocation Table. When you take a picture, the camera sends it to the Card BIOS, which writes it to the card. It also makes an entry in the FAT so it can find it again. When you delete a file, the file is NOT touched. It is still on the card. What gets deleted is the entry for it in the file allocation table. When you format, all of the references in the file allocation table are deleted. AND ALL OF YOUR PICTURES ARE STILL ON THE DISK! You just have no way to get to them because the FAT has been erased. This is where the entire field of data recovery comes in. FBI can recover stuff you thought was gone forever.

As the previous poster said, formatting only over-writes a very small portion of your card. This guy (girl?) doesn't even have a clue that they don't have a clue.

TSchrief wrote in post #14846828
All information about where your pictures are located is stored in the File Allocation Table. ..
When you delete a file, .... What gets deleted is the entry for it in the file allocation table.

When you format,... the FAT has been erased.

I think you were confused by my post.. In agreement with your prior post, I said the advice that uOpt gave was bogus.

You seem to being agreeing with that. When you format or erase all of the files, either way, you are re-witting the FAT... aka "the most import sectors."

When you erase, you go through the FAT entry by entry, when you format, you just reset it.

TSchrief wrote in post #14846828
This is where the entire field of data recovery comes in. FBI can recover stuff you thought was gone forever.

LOL.. I never thought it was gone forever, and it certainly doesn't take the FBI to get it back! When I want to really remove files, I use tools like: Disk Eraser, though I have never used it on a memory card.

hairy_moth wrote in post #14847503
I think you were confused by my post.. In agreement with your prior post, I said the advice that uOpt gave was bogus.

You seem to being agreeing with that. When you format or erase all of the files, either way, you are re-witting the FAT... aka "the most import sectors."

When you erase, you go through the FAT entry by entry, when you format, you just reset it.

"Erasing" a file (be it a photo file or any other file) on a hard drive or a memory card does NOT touch the file itself. The act of "erasing" a file only tells the File Allocation Table to make the space that the file currently resides in available for writing other files.

I sometimes reformat my camera's memory cards in the computer. I always reformat the cards in the camera after moving image files to my computer. One would think that this combination of processes would actually remove the image files from the card. WRONG. After doing this combination of processes to one of my cards many times, the card became corrupted and I could not read any image files from a photo session. I then used a file recovery software program to recover my day's images. Not only did I get the day's images back (at least most of them), but I got many very old images back. At some time in the past I apparently had nearly filled the card. Since that time, I only used maybe half of the card. Whatever images were not over-written with new ones were still on the card and were made available again by the recovery software.

I don't think anyone even implied that removing files or reformatting the card actually erases the files -- I certainly never did. When I said "a lot more" I meant it goes through the entire FAT, entry by entry, not the actual image data. If you want to do that, you need a tool like Disk Eraser.

The first time "removing the actual picture data" was mentioned was when TSchrief (apparently) misunderstood my comment "a lot more" to mean the picture data.. it meant going through the FAT entry by entry.

hairy_moth wrote in post #14847636
I don't think anyone even implied that removing files or reformatting the card actually erases the files -- I certainly never did. When I said "a lot more" I meant it goes through the entire FAT, entry by entry, not the actual image data. If you want to do that, you need a tool like Disk Eraser.

The first time "removing the actual picture data" was mentioned was when TSchrief (apparently) misunderstood my comment "a lot more" to mean the picture data.. it meant going through the FAT entry by entry.

hairy-moth: Yes, you are correct. I did misunderstand your comment. I assumed that "a lot more" was referring to the actual picture data, as you say. I have a tendency to (mis-)interpret first, think later. Sorry for my brashness.

This thread points out the need to write in a non-ambiguous way. The "a lot more" could be easily mis-interpreted.

In my last post, I wasn't pointing fingers at anyone but merely trying to state things in a way that couldn't be mistaken.

SkipD wrote in post #14847941
This thread points out the need to write in a non-ambiguous way. The "a lot more" could be easily mis-interpreted.

In my last post, I wasn't pointing fingers at anyone but merely trying to state things in a way that couldn't be mistaken.

Agreed!

SkipD wrote in post #14847523
"Erasing" a file (be it a photo file or any other file) on a hard drive or a memory card does NOT touch the file itself. The act of "erasing" a file only tells the File Allocation Table to make the space that the file currently resides in available for writing other files.

I sometimes reformat my camera's memory cards in the computer. I always reformat the cards in the camera after moving image files to my computer. One would think that this combination of processes would actually remove the image files from the card. WRONG. After doing this combination of processes to one of my cards many times, the card became corrupted and I could not read any image files from a photo session. I then used a file recovery software program to recover my day's images. Not only did I get the day's images back (at least most of them), but I got many very old images back. At some time in the past I apparently had nearly filled the card. Since that time, I only used maybe half of the card. Whatever images were not over-written with new ones were still on the card and were made available again by the recovery software.

Indeed. I accidentally formatted a card at a wedding once. I promptly put it in my bag and when I got home I recovered all of those images and many from the past.

SkipD wrote in post #14847523
After doing this combination of processes to one of my cards many times, the card became corrupted and I could not read any image files from a photo session.

I forgot to put in my previous post that the CF card in question has been fine ever since the single corruption incident. The card did not go up in smoke or anything like that.

As far as I see it, the only sensible way to get rid of the images after uploading them to the computer is to give the "Erase all images" command.

Formatting is a no-no, since it will ruin the folder structure on my cards. I have several named folders, and for easy reference after shooting something I let the camera store the images in the different folders. That would be ruined if I formatted the card.

Formatting is a no-no, since there may be some specific picture I'd like to keep, and protecting it will not be respected by formatting. It would remove even pictures I've told the camera are important to keep.

Formatting is a no-no, since it will wipe out setup data that's stored on the card. I have settings for particular access points stored on the card, and want to keep them also after deleting images.

apersson850 wrote in post #14849472
As far as I see it, the only sensible way to get rid of the images after uploading them to the computer is to give the "Erase all images" command.

Formatting is a no-no, since it will ruin the folder structure on my cards. I have several named folders, and for easy reference after shooting something I let the camera store the images in the different folders. That would be ruined if I formatted the card.

Formatting is a no-no, since there may be some specific picture I'd like to keep, and protecting it will not be respected by formatting. It would remove even pictures I've told the camera are important to keep.

Formatting is a no-no, since it will wipe out setup data that's stored on the card. I have settings for particular access points stored on the card, and want to keep them also after deleting images.

I don't know about the setup data, but it would take two minutes to write an executable batch file that would format your card and the add whatever folder system you wanted.

Name the file: formatcard.bat
text in the file follows
format x:
md x:\firstfoldername
md x:\firstfoldername\sub​foldername
md x:\secondfoldername\su​bfoldername
end of text in file

You can get a lot fancier, but it gets the job done. You cam add a line for each folder you want to make. The (x is whatever your card is referred to when in your computer.
When you want to format just double-click the file name, storing it on your desktop helps.