# Formatting vs Deleting and where should it be done



## bohaiboy (Jun 11, 2012)

Ok, original formnat in camera, I assume that it should not need reformatting unless used in a different camera. But what about deleting pics from a card, should it be performed in-camera or via the computer? ALso a question, I have a 5DIII with the two slots for CF and SD. I have it set up for RAW o the CF and Hi JPG to the SD. After I download to my memory backup every night, should I continue shooting as is or delete all the pics from the previous day?

Thanks all, off on a safari tomorrow.


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## Jettatore (Jun 12, 2012)

First time you put a card in a camera, have the camera format that card for you. I have no problems deleting individual files on the camera. After my files are backed up in at least two places (preferably with a copy online or at least two copies in different physical locations in case of theft/fire (knock on wood)) you can format the card again in the camera. If you were to format the card on a computer ever, I would personally have the camera it's going back into re-format it, that bit might be unnecessary but I've had great luck. I also have only used the cable attached to the camera to transfer files, not sure if that is best but it's worked so far so well.


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## neuroanatomist (Jun 12, 2012)

I format the card every time I put it back in the camera (after images are backed up in 2+ locations). Formatting errors crop up over time, so occasional formatting is good - I just use the format step to delete the images from the card (obviously, I have multiple cards).


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## Mt Spokane Photography (Jun 12, 2012)

neuroanatomist said:


> I format the card every time I put it back in the camera (after images are backed up in 2+ locations). Formatting errors crop up over time, so occasional formatting is good - I just use the format step to delete the images from the card (obviously, I have multiple cards).


 
Same as Neuro.

However, with the 5D MK III, for SD cards, you have the option of a quick format or a low level format in camera. I do the quick format to delete images, but about every 3 months, I would do a low level format. I also do a low level format of my CF cards in my computer about 2 -3 times a year.

A low level format will write to every memory location on your card, and map out bad locations. This helps you keep from getting corrupted images every time your camera writes to that bad memory location.


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## scottkinfw (Jun 12, 2012)

I format every time in camera to prevent data corruption. Deleting on camera is NOT the same thing.

sek



Mt Spokane Photography said:


> neuroanatomist said:
> 
> 
> > I format the card every time I put it back in the camera (after images are backed up in 2+ locations). Formatting errors crop up over time, so occasional formatting is good - I just use the format step to delete the images from the card (obviously, I have multiple cards).
> ...


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## keithfullermusic (Jun 12, 2012)

I only delete. I haven't had a problem in 4 years with the same card. Maybe I should format instead, but I usually just have aperture delete the pics after I've loaded them.


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## pwp (Jun 12, 2012)

After speaking to CPS on the subject some time ago, the recommended strategy for the long & stable life of the CF card is to do as Dr Neuro suggests, and that's to format in camera every time you put the card back in the camera after downloading. They add to that the recommendation to format in your computer via your card reader with a FAT32 format. FAT formats are for older cards under 1Gb. Do this two or three times a year.

But they added that for greater stability, avoid deleting images in camera and do your edit when you get back to the studio. The cost per Gb is so low now, deleting on location is barely necessary.

The third stability strategy is to avoid using your cards across other devices or even brands of cameras. If you do, make a point of doing a full FAT32 format first.

Lastly, take your CF card out of your jeans pocket before putting them in the wash. I've done it twice. Both times they came out noticeably cleaner, but one led to card failure. Wrong brand of detergent I guess!

Other than the wash incident, I've never had card failure or corruption, and that's over 12 years now. I've followed those basic rules, and always bought Sandisk cards. There used to be a lot of talk about failed cards...often they were Lexar or low cost no-name cheapies. Lexar may be better now but I'm staying with Sandisk. Also I generally replace cards after a couple of years, regardless of performance or perceived stability. Overkill? Maybe, but professional credibility is hard earned over time but can be lost in a heartbeat. 

HTH

PW


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## Marsu42 (Jun 12, 2012)

neuroanatomist said:


> I format the card every time I put it back in the camera



Is there any real evidence this is better than just deleting the pictures? I've never formatted my card because it has the magic lantern files on it, and never ran into a problem even after 80k shots. Furthermore, I often put old, but postprocessed shots back in the camera as a reference.


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## PeterJ (Jun 12, 2012)

Marsu42 said:


> neuroanatomist said:
> 
> 
> > I format the card every time I put it back in the camera
> ...


Pretty sure any evidence you'll get will be pretty anecdotal, I'm sure corruption problems using either method are so rare they'll be many like you that've never had a problem or others that say they they switched to formatting after losing files when it was really some other problem.

I work with embedded electronics and tend to use the format method to put everything back to a known starting point. My theory is that it means every time I use the camera to record images the file structure is in exactly the same state that Canon no doubt do their most testing with. If Canon's FAT code is 100% error free, Apple / MS / Linux code is 100% error free and they both interpret the standard exactly the same way then ideally there should never be a problem with just deleting.

I've only just started using Magic Lantern on a 5D2 (previously had a 450D and 7D both incompatible) but the latest version has an option to format but leave the ML files intact. I'm not sure what it does behind the scenes though, it obviously doesn't do the usual complete format but might take steps to put the FAT tables back into the same state as when installed, although I'm guessing as it seems to scan the files it might just delete anything else.


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## Kumakun (Jun 12, 2012)

I also format the card when I put it back in the camera after backing it up (usually on two external hard drives as well as on my computer). I've never had any problems losing shots due to bad cards; still have my old 2 and 4 GB cards from when I was using my old Rebel XTi.

On the subject of cards... I recently started using my 5DIII and am now getting used to having dual slots. The file sizes are a bit larger than on my 7D so I started running a little short on space (was using a 16GB card). Started chimping in camera to open up space, but the top LCD still showed I had the same number of shots remaining. Took me a couple seconds to realize what was happening. I had switched my review to the SD card (shooting JPEG) and had my CF card shooting RAW, so chimping wasn't saving me any space on my CF. Fortunately, this wasn't a situation where I was in any danger of running out of memory (I had about 70 shots at the end of the night, and had a spare card if I needed). But it helped me realize that the dual cards require a little bit more thought than a single slot.


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## PeterJ (Jun 12, 2012)

dilbert said:


> The camera does not do a real format - it does a "Quick Format".


So what would a full format do differently on solid-state memory? On older HDD drives it used to write sector markers to align them. For FLASH it could detect bad pages by writing patterns and reading them back, but that would also reduce the lifetime needing extra page erase cycles.


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## Mt Spokane Photography (Jun 12, 2012)

scottkinfw said:


> I format every time in camera to prevent data corruption. Deleting on camera is NOT the same thing.
> 
> sek


 
In camera formatting merely marks the files as deleted in the fat tables, it does not check for corrupt sectors and will not prevent data corruption due to bad memory locations.


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## RLPhoto (Jun 13, 2012)

I format the card in camera. Its still possible to recover photos from a formatted card as long as you dont shoot anymore photos into it.


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