As I understand it low level formatting a flash memory card puts the card back to the unprogrammed state. High level formatting is just reapplying a file system, your data is still retrievable.

My guess?
Since we know data gets corrupted from time to time, this corruption can be insignificant enough to not cause any major issues, but significant enough to cause an issue with the write process of the camera. Laying down a new file system somehow fixes this. I honestly don't understand why either, but I have used a Transcend 6 card since I got the camera and formatting the card in camera has fixed issues for me as well. Something I cannot do now due to the way I have ML "installed". Fortunately I haven't had any issues lately.

Does Sandisk have the industry's lowest rated error spec? Maybe that's why Canon advises using them? I honestly don't know.

(Expert opinion is meaningless to me, I don't meekly do what experts say.)

Andy,

A math teacher I worked with explained "An Expert" to me like this:

In math, "X" is an unknown and a "spirt" is a "drip under pressure."

Therefore, he concluded, an Expert is an "Unknown Drip under pressure."

 

Quote from: bandmandq on February 03, 2012, 07:59:42 AM

... an Expert is an "Unknown Drip under pressure."

I've known that joke for a while with "ex" as in "has-been" but I think I like your version better!

Well, glad you enjoyed!

I just found this link with a quick Google search on Low Level Format.  I am sure you already found it, but it answers a lot to me.  I was one for always doing that low level format, just didn't know why.

http://photography-on-the.net/forum/showthread.php?t=111395

Hope this helps.

bandmandq

My 60D and T3i both offer a low level format option.  Pressing the "trashcan" button toggles between check and uncheck that "box".  I use it, it's gotta be there for a reason.

Oh, it's there for a reason all right. As I understand it, these are your erasure options:

1. Deleting files: changes the first letter of the filename to 0xE5 which labels it as deleted; marks all the relevant sectors as 'unused'.
2. Quick format: writes an empty directory structure, and labels all the sectors as unused.
3. Low-level format: writes an empty directory structure, and labels all the sectors as unused, and writes "0" to all memory locations, removing your old photo data.

So a low-level format would be useful if you had nude pics of your wife and wanted to sell the card on, yet be sure that no one could recover the files. Not so useful for a professional photographer where you might just need that recovery option one day.

I use SanDisk, format the card (in camera) first thing after purchase, and after each use (once I have my image/video files safely on two external hard drives) and I've never had a card problem.  If you choose to believe this to be "formatting madness" that is your prerogative.  You may stand a very good chance of losing something down the road.

You misunderstand me, Bif - I'm not arguing with you. I've never said there's anything wrong with formatting instead of deleting, but hitherto I've always claimed that it's equivalent since no one has offered any explanation as to why it would be otherwise. However, I do think that low-level formatting is a bit stupid because it takes longer, and writes over your photo data, which doesn't gain you anything but removes your option to recover it later.

Now that I've noticed a real difference between formatting (quick) and erasing, I have started doing a quick format instead. What is "madness" is the fact that I'm doing this on purely empirical evidence, and not for any rational reason.

I have read that thread linked to, and it's interesting for sure, but it contains opinions which are sound, and opinions which are clearly wrong-headed, with no way to tell the difference. The only real way to the truth is for someone to come up with a reason that passes a 'plausibility test' - something I can put a label on, but can't define - which satisfies me that it shows that the opinion behind it is true.

Most pro's do format media regularly.

And some interested amateurs, now ;-)