TriX Loc: Raleigh, NC

You should not need to low level format the card(s) to make the image files inaccessible. Quick or high level formatting does not erase the images, but it makes them inaccessible and the sectors capable of being overwritten by changing the entries in the allocation table of the drive. Low level formatting creates the file structure on the drive and depending on the file system, may write to and check each sector on the drive. It should not be required and isn’t a great practice on an SD card. SD cards are NAND flash devices and have a large, but not unlimited number of erase/write cycles, and low level formatting after every use is essentially wasting half of that maximum number. Now whether that will affect you depends on how often you use and LLF the card, but it’s an unnecessary waste of time and card life unless there’s a valid reason to do it such as initializing a new card, giving away a card with data, experiencing slow performance or repairing a corrupted card. It also has the disadvantage of making any previously written files irrecoverable should you need to do that in an emergency when data is accidentally lost.

hcmcdole

I sometimes forget to format the second card and the images are still on it. I wished the format command had a 3rd option to format both cards at the same time.

roger

This is my understanding, so please correct me if wrong. Technically, formatting does not erase the images. They're still there. What formatting really does is erase the data which directs camera/computer/other to the individual segments on the card.

SuperflyTNT Loc: Manassas VA

It actually doesn’t erase any photos. It erases the data from the FAT table. That’s why they can be recovered, the data is still there just no way to get to it directly. It’s like removing photos from your Lightroom catalog. The images are there but Lightroom no longer knows about them.

SuperflyTNT Loc: Manassas VA

Exactly. A regular format doesn’t touch the data, it just deletes everything from the FAT table, which is basically a directory of files and their locations.

brianajo Loc: Youngstown, Oh

try deleting all images first, then reformat

SuperflyTNT Loc: Manassas VA

Deleting the images does the same thing as format. When you delete the data is still there until it’s overwritten. The entry for that file is just deleted from the FAT.

LFingar Loc: Claverack, NY

Depends on the format. A quick format leaves the files in place but makes them inaccessable unless you have a recovery program. A low or full format overwrites the data making it useless although there are some very sophisticated programs, such as those used by the FBI and various intelligence services that can recover at least a portion of the overwritten data. That is why there are programs that overwrite the data not just once but multiple times making all data unrecoverable. Put a card into a Windows computer, and, I would assume, a Mac, do a quick format and it takes only seconds. Un-check the Quick Format box and that same format will take much longer because now all data is being overwritten.
Canon does it a bit differently, according to a Sandisk tech I talked to some years back. Instead of overwriting data with random ones and zeros, as a typical full format does, it does a batch reset of all the data sectors to zero. Canon writes to the card using only ones. I assume they figure it is quicker, and it is, for Canon anyway. On a heavily used card it uses zero formatted sectors first, leaving randomly formatted sectors to last. The write time slows down when writing to the random sectors because it first has to zero format them. That is why in the format section of Canon manuals it tells you to do a Low format to restore full write speed to the card if it is writing slow.

Picture Taker Loc: Michigan Thumb

I don't have this problem with my R5 or R6. Call Canon Tech. (877)287-7032

josquin1 Loc: Massachusetts

Call Canon support; 800-652-2666. You bought the cameras and that includes getting help from them. They are really very good.

WoodturnerJohn Loc: Pittsburgh PA

I’m confused, After the initial formatting new SD cards why reformat after taking pictures? After taking photos, I load them on my computer then from the camera menu erase all then I’m good to go.

CHG_CANON Loc: the Windy City

You are good to go with 'delete' as 'erase' isn't on the camera menu.

Different systems / cameras behave differently. Personally, on my EOS DSLRs, I use the 'delete-all' function as the sequence to that menu option is easier (faster) to reach than 'format'. But, on my Sony MILC, the 'format' command is the easier to access menu command. I just do what's faster as the results are the same.

WoodturnerJohn Loc: Pittsburgh PA

Ok, you caught me, you’re of course correct I delete-all, not erase. Still why would one reformat rather than delete?

SuperflyTNT Loc: Manassas VA

Because deleting could possibly leave artifacts. Formatting deletes the folders too which get recreated. I usually format. The one instance I would delete is if I had a camera that saved settings to the card. You can lock them and delete won’t touch them but format will.

larryepage Loc: North Texas area

First off...I don't know how the Canon system works. I do know that when I reformat cards in my Nikon cameras, also deleted is the file containing the backup for all of my custom setup configuration. "Moving" the files to their destination leaves that file intact. It would not be a huge inconvenience to just save those settings each time, but I've found no reason to need to put up with the inconvenience of having to remember to do that.