Reformatting of CF memory cards, and cooties

Often, we see one or the other of these pieces of advice regarding CF cards:

1. It is better when wishing to clear all image files from a CF card to reformat the card than to delete all the image files.

2. Even if not using reformat to clear the card, one should periodically reformat it retain best performance, possibly even to avert some misbehavior.

3. One should always reformat a new card in the camera in which it is to be used before actually using it for shots.

4. One should not use the same card first in one camera and then in another without reformatting it.

(There are clearly some overlaps among these axioms.)

Almost always when I see one or the other of these written, I invite the author to help me by explaining what actual technical phenomena are being averted by following it. The results have never been satisfying.

Among the responses I get are (I will give the key number of the pertinent recommendation in parentheses):

A. (1) Clearing all the files by reformatting is faster than by deleting all files. (Sometimes this is said in the context of doing it in the camera; other times, it is in the context of doing this with the card in a card reader, and of course various tools are discussed.)

B. (1) Clearing all the files by deletion vs. reformatting uses up more of the card's finite life of read-write cycles.

C. (1, 2) Doing this gets rid of file fragmentation, which will otherwise accumulate over time, and which can degrade the performance (notably write and/or read speed) of the card.

D. (3, 4) If you don't, you will expose yourselves to the possibilities of corrupting the card, losing files, or getting cooties. (Details of the actual presumed potential technical mechanisms for such are never forthcoming.)

My take on these has always been as follows for the different cases:

A. Yeah, probably, although I'm not really sure.

B. Yeah, I guess. I'm sure I'll wear out the connector long before.

C. Hard to believe. If we periodically clear all files from the disk (even by bulk deletion) of individual files, the FAT is all set to "available") (except for defective clusters), and presumably the O/S will then write each file added in contiguous clusters. And we don't normally "re-write" the same file. (I actually don't understand why even the presence of fragmentation on a static memory would cause performance degradation, but I understand that it will, although certainly not to the degree it would in a hard disk drive.)

D. My mother said that cooties were only a problem at the end of town were the factory was.

So, what can those of you who know more than I about mass storage management tell me about the reality here?

For my own part, I only once in my life ever reformatted a CF card, and that was for testing of the effect of different cluster sizes on the ability of a Fuji S602 to write "streaming video" to the card. I take new ones out of their blister packs and, after adding my "owner information" text file, bang 'em into the camera. I move them between cameras (normally cleaning off all the files and directory structures before I do, by deletion, to prevent folder and file numbering derangement).

The cootiephobes point out that my entire data recording life is on borrowed time and that God will strike me down as soon as He gets around to it.

A recent horror story (told on dpr, of course) is of a 5D that always writes corrupt .CR2 files. It is believed to be because it once was penetrated by an impure CF card.

Thanks, gang.

I couldn't agree with you more Doug! There is so much FUD around these things that it is downright funny.

A) Maybe. Is it a noticeable difference? Probably not. Certainly with a tool like Downloader Pro it is much much faster to simply hit the Delete All button in the app than having to go and reformat the card in another tool.

B) I seriously doubt that. In the end, from a hardware/electronics "wear" perspective, it is the same thing. Unless reformatting a CF card is somehow much different than a HDD. But, I'm not sure...

C) File fragmentation on deleted files? No way!

D) Ahem...

my take:
a) i have a mac so no downloader pro i format in the camera always because that way i have one more chance to Not Erase them
d) true LOL! just kidding...

seriously though, all i know is that in 5 years and many many many card reformats in camera i have yet to have a corrupted card or an undownloadable image.
not scientific, just practical.

Hi Doug,

1. It is better when wishing to clear all image files from a CF card to reformat the card than to delete all the image files.

Click to expand...

I think that will need to be rephrased to get a 'better' answer. What does 'better' mean in this instance? It is a compromise speed/low cost/reliability/etc. you can't have them all. This is why there is fud, Chinese whispers, folk not actually reading the answers or understanding the questions. Standards continually eroded, etc.

To answer just the first question you pose, will require you to research enough to write four of five papers in your 'pumpkin'.

In my case, I leave the card in the camera - download via usb to pc, reformat in camera. If I'm away from base, then if the cf gets full, it is removed, sucked off into hyperdrive, then formatted in camera. That is better for me. Why? Do you want to know why?

Best wishes,

Ray

Hi, Ray,

Ray West said:

Hi Doug,

I think that will need to be rephrased to get a 'better' answer. What does 'better' mean in this instance? It is a compromise speed/low cost/reliability/etc. you can't have them all. This is why there is fud, Chinese whispers, folk not actually reading the answers or understanding the questions. Standards continually eroded, etc.

Click to expand...

Of course.

To answer just the first question you pose, will require you to research enough to write four of five papers in your 'pumpkin'.

Click to expand...

Indeed.

In my case, I leave the card in the camera - download via usb to pc, reformat in camera. If I'm away from base, then if the cf gets full, it is removed, sucked off into hyperdrive, then formatted in camera. That is better for me. Why? Do you want to know why?

Click to expand...

Sure.

Thanks.

Best regards,

Doug

It's a tricky question to be sure. I'm not specifically educated in the area but this is another collection of issues I've seen arise within the good old retail environment.

1. It is better when wishing to clear all image files from a CF card to reformat the card than to delete all the image files.

I do agree with this, though I believe this is more of an issue with digicams then with SLR's. I can't explain why or how it happens, but every day or so we'd get one customer who's memory card messed up in a mysterious way. I'd jam the card into our PC and see what's going on. Somehow, the camera has inserted what seemed to be a file filled with garble. The customer would claim that no photos were lost or corrupted, nor had the memory card even left the camera, and they didn't format.

How did this file get there? I honestly have no idea, but I would see really random files which are literally random letters and numbers and the card wont accept any more photos. A simple format fixed it entirely, and this happened fairly often. Eh? This has never happened on an SLR either. If anyone can comment, that will help.

2. Even if not using reformat to clear the card, one should periodically reformat it retain best performance, possibly even to avert some misbehavior.

This is slightly in conjunction with the above answer, but is a bit more relevant to SLR's. Say for example on my 20D I did a full 9999 image name cycle over a period of time, It would make a new folder for every 100 images. If I just deleted the images the folders remain, once again I'm no expert, but I doubt its efficient for the camera to hunt through 100 folders when looking at images or deciding which folder to go into next. I realise thats not an issue for every camera (I know the 30D makes a new folder every 9999 photos).

3. One should always reformat a new card in the camera in which it is to be used before actually using it for shots.

Thats bull for modern cameras, new memory cards are formatted, they're blank. A modern camera will simple create the nessesary folders if they're not to be found, formatting not required. Once again may be an old tale from a few years back but any self respecting camera wont have that issue.

Also, check the other thread on here regarding that as well, it's not *always* recommended - http://www.openphotographyforums.com/forums/showthread.php?t=3304

4. One should not use the same card first in one camera and then in another without reformatting it.

This is partially true but not a you have to do it or your card will have a heart attack! piece of advice. I know that if you take some photos on a 20D, then place that card into a 5D there is a chance the 20D images will be removed. Also a cameras filing system might look at a card and go "why is there a folder already there with a name I don't know? ARGH?!" and force a format on the card before it can be used or delete said folder.

Once again I don't think this is an issue on modern cameras, I've used memory cards which have folders containing anything from .txt files to mp3 files, absolutely fine. Sometimes though, an in camera format wont remove the custom folders, I have forgotten about said folders and files in a card before which obviously reduced the capacity of my card when shooting and not realise untill I upload photos after the shoot.

Those are the general issues I've known with cards, I would see it as a good habit to format cards but alas I can't help with the technical reasons behind it. I have a feeling that alot of the issues are from 4+ years ago when cameras filing systems were possibly a bit more basic and less tolerant of other files found within memory cards.

Anyone else able to advance or give reason behind these?

The following information is completely anecdotal, reflects my experience only, and is not to be construed as advice to anyone!

I have never followed any of the "rules" listed:

1. I always just delete the files from the card in the card reader after I've confirmed they are all safely on the HDD. I have never had "ghosts," "cooties," or fragmentation. Not reformatting preserves the name I assign to the disk.

2. Once I experienced a small capacity decrease after about a dozen uses of the card. Turned out I was deleting the photo files only, and not the empty folders. I now drag the folder of files to the trash when emptying the CF card.

3. I would hope that there are not differences in format between different cards and different cameras such that this is even necessary these days.

4. I move cards back and forth between my 30D and my 300D freely, and even manage to preserve file numbering because the file extensions and folder numbering is different between the cameras.

My $0.02 worth (about 1,5 Euro cents) Your Mileage May Vary

I never reformat CF cards even when switching between cameras, just delete the images either on the PC or in the camera. Never had a problem.

- DL

Hi, Marc,

Marc Hankins said:

This is slightly in conjunction with the above answer, but is a bit more relevant to SLR's. Say for example on my 20D I did a full 9999 image name cycle over a period of time, It would make a new folder for every 100 images. If I just deleted the images the folders remain, once again I'm no expert, but I doubt its efficient for the camera to hunt through 100 folders when looking at images or deciding which folder to go into next.

Click to expand...

I don't think the camera "has to hunt through 100 folders". For example, when it is about to write the next file, it knows what folder it will go in and what its filename is. If there are lots of other folders, that doesn't get in the road of that at all.

By the way, when I spoke of "cleaning all the files off the card" I meant "cleaning off all the files and folders", but was too lazy to articulate it!

Best regards,

Doug

When my primary computer was based on Windows, I only reformatted my card once or twice -- and then only because my first digital instructor was adamant that I do this. From that point forward, I just deleted the files on the CF card from my Windows file manager du jour. This was my routine for a couple years. Never formatted my card again. And life was pretty good.

When I switched to a Mac, it never occurred to me to revisit this routine. I was out on my first shoot and my CF card was full after just a few dozen shots. I pulled out another card. Yipes. It was nearly full too!

I'll spare you all the intervening agony -- the long story shortened is that on my particular Mac (your mileage may vary) when you delete files you don't really delete files.... you only move them to a hidden folder named 'trashies'.

My routine now includes reformatting the CF card every time. I do it with the camera. No more trashies.

Ron

Hi, Ron,

ron_hiner said:

I'll spare you all the intervening agony -- the long story shortened is that on my particular Mac (your mileage may vary) when you delete files you don't really delete files.... you only move them to a hidden folder named 'trashies'.

Click to expand...

Yeah, who'd a thunk it!

Of course Windows will offer to do that on deletes from fixed media drives, but doesn't offer (maybe won't even do it) on removable media drives. And the folder isn't really "hidden".

Best regards,

Doug

Here's how we do on a daily bases: format all the cards with the body you are using, place in box (or those great Gepe plastic water proof containers). Put card in camera, shoot. When done, download to computer and backup. Get back home, proof the files for errors, only now after everyhting is checked and backed up reformat the card. Some times i erase a file or two but for the most part i keep everything and sort it out in lightroom or C1pro. Once every month we do a clean swipe with RescuePro from Scandisk. Never any lost/corrupt files ever and as far as cards wearing out, maybe, but i still have to see that, treat your cards like treasures, keep em clean and protected, that keeps the contacts clean etc and it's all good. I recently broke open an old CF card and it was, i kid you not, very difficult, physically challenging (yes, i do go to the gym) and inside straight forward simple. The only fragile part it seemed were the contacts.
Cheers
M

Doug_Kerr said:

Often, we see one or the other of these pieces of advice regarding CF cards:

1. It is better when wishing to clear all image files from a CF card to reformat the card than to delete all the image files.

2. Even if not using reformat to clear the card, one should periodically reformat it retain best performance, possibly even to avert some misbehavior.

3. One should always reformat a new card in the camera in which it is to be used before actually using it for shots.

4. One should not use the same card first in one camera and then in another without reformatting it.

So, what can those of you who know more than I about mass storage management tell me about the reality here?

Thanks, gang.

Click to expand...

I can give you one reason for format over delete.

When I take a card with photos taken on my 1Ds and put it in my 5D it won't read the files so the only way to erase the files is with a format.

The same thing holds true with a card with photos from my 5D on it. The only way to erase the files is to do a format.

> The same thing holds true with a card with photos from my 5D on it. The only way to erase the files is to do a format.

Perhaps "in the camera". I'm one who never formats, only deletes, but I normally delete while in the PC card reader not in the camera.

- DL

I just right-click drag the numbered image folders off of the card, and onto the target medium.

It is fool-proof in Windows. You right-click and drag, and select "Move" from the context menu, and if the folder already exists and it asks you to overwrite, say "yes" only to the single yes, and not "yes to all". As long as no further warning comes up telling you that a file has been asked to be over-written, and you click "yes" for this, then no files can be overwritten. Overwriting a folder when dragging it, is non-destructive, and only updates the time-stamp of the folder itself.

After all the folders have been moved, only the empty DCIM folder is left.

ron_hiner said:

When I switched to a Mac, it never occurred to me to revisit this routine. I was out on my first shoot and my CF card was full after just a few dozen shots. I pulled out another card. Yipes. It was nearly full too!

I'll spare you all the intervening agony -- the long story shortened is that on my particular Mac (your mileage may vary) when you delete files you don't really delete files.... you only move them to a hidden folder named 'trashies'.

Click to expand...

Hi Ron
'normally', on a Mac, when a file is trashed (drag to trash folder on desktop), you have to do a "Empty trash" from the Finder menu (or Command/shift/delete shortcut)… other wise your files stays in the trash bin and place isn't freed from your card (or any device)…

BTW I always format in camera the cards before shooting…

Keeping it as simple as possible is probably the best route, like Don does. From the D30 to the D60 to the 20D to the 5D and even an SD800 and other pocket cameras, I always use a PC card reader to transfer files and then delete the folder(s) and contents on the card while it's in the card reader (Windows).

Not buying bargain basement CF cards and sticking with top-rated (Rob Galbraith) cards may help, too.

Many of the myths surrounding what works and what doesn't work with CF cards probably evolved from anecdotal fixes that happened to work once or twice because the circumstances that caused the failure changed, or work when not at all necessary, and are carried forward because "that always works for me, you should try it" and then it gets more and more complicated as the experience of someone else gets added into the process.

It's like the family cook who always cuts the end off the turkey before baking it. Finally someone asked why? The answer is "because that's the way I've always done it and that's the way my mother did it". The reason? Many years before the family had a roaster that was always too small to hold the turkey, so part of the turkey had to be cut off to fit into the roaster. After enough years had passed, just about everyone forgot why this mystical approach to cooking the turkey was required. It just was and if that rule wasn't followed of course the turkey would not taste as good.

The same may apply to cooking CF cards!

Mike

Or you could just delete the folder called trashies, using an IOS that allows you to see it.

(Windows has the same issue btw, although by default the trash for all volumes is on drive c so it does not take up space on your memory cards).

Doug_Kerr said:

Often, we see one or the other of these pieces of advice regarding CF cards:

1. It is better when wishing to clear all image files from a CF card to reformat the card than to delete all the image files.

2. Even if not using reformat to clear the card, one should periodically reformat it retain best performance, possibly even to avert some misbehavior.

3. One should always reformat a new card in the camera in which it is to be used before actually using it for shots.

4. One should not use the same card first in one camera and then in another without reformatting it.

Click to expand...

Caveat: my experience includes SD cards as well as CF cards.

1. may well be faster, depending on the computer you are using and whether it offers 'quick format' (ie zap the FAT) or onlly a full format

2. have not tried to verify this experimentally, but if testing cards I d reformat before each test simply to reduce the number of possible variables.

3. This is a simplification of 'your computer may format as FAT32 or NTFS but your camera only understands FAT16 so format in your camera is always safe'. Which was true until cameras started understanding FAT32 and always meant that you could format in the computer as long as you did not pick a stupid setting.

However, I have seen SD cards whose initial formatting was understood by a computer but which did not, apparently, meet the standards of the SD association. Whether this had any practical effect i am not sure.

4. I do that all the time without ill effect; I also use the same CF or SD card to transfer non-image files between computers while also using it on multiple cameras. Never had a problem with it.

I should add that I have only twice had issues (file corruption) with a memory card. Both were with a Lexar CF card (in fact, the same card) and involved incomplete image saving such that the jpef thumbnail was saved but the image itself was corrupted. The first time it had half of the previous image. the second time it had random noise. I no longer have that CF card (it went along with my Miniolta A1 when it was stolen). I have never had any image corruption issues on any other CF or SD card.

In terms of performance, I do notice (small) differences in SD card performance depending on how they are formatted. Treat that as anecdotal until I have more data.