# Question About Memory Card Failures



## Pixelman (Oct 17, 2018)

Hi. New to this forum and new to Canon. I am not a working professional but do value my images.My recent cameras have had dual slots for memory cards. But I've never had any failures. Due to the R's single slot I'm wondering what would be the symptoms of a failure. Does the camera give an error message so that you know to change the card? 
Thanks.


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## Mt Spokane Photography (Oct 17, 2018)

Generally, a failure happens to a few of the memory cells, and the camera will not give you a error. There is software that will let you reformat a card at low level, one cell at a time, and it will mark bad cells as unusable, so they are basically put out of the read / write process. Its silent though, so you don't know it happened.

Memory card bad cells which are not marked as bad by the controller can very hard to find, a 64GB card with a few bad cells might not save to one of them but infrequently, so you will think its a random error.

If you are getting corrupted images, a 2nd card should not be affected unless its a camera issue.

With a single card camera used in a situation where loss of images is critical, use raw + jpeg, its not likely that both will be corrupted by a random bad memory location.

If the card just fails, you will get a error, so pop in another and try to repeat the lost images.


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## Valvebounce (Oct 17, 2018)

Hi Pixelman. 
Generally no warning, (unless it is already dead then the camera may give a cannot access card or a no card warning unless you have shoot without card enabled?) the first you know is the card reader/computer can’t find any or all the images, however, this is also a symptom of a failing card reader or its cable so best to check that first if having problems. 

Cheers, Graham. 



Pixelman said:


> Hi. New to this forum and new to Canon. I am not a working professional but do value my images.My recent cameras have had dual slots for memory cards. But I've never had any failures. Due to the R's single slot I'm wondering what would be the symptoms of a failure. Does the camera give an error message so that you know to change the card?
> Thanks.


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## old-pr-pix (Oct 18, 2018)

So far I have only ever had one card failure. I put a new, well respected name brand SD card in my 60D. Did an in-camera format and started shooting. After about 15 shots the next shot displayed "Card Error" when camera attempted to write to card. I was shooting real estate at the time so I just changed to a different card, re-shot a couple of the shots, and went on. I was only able to recover 3 of the 15 images on the bad card using manufacturer supplied recovery software. That was when I decided for me all future bodies should have dual cards. But, to be honest, even though I now have dual slots, there are times there aren't cards in both slots. Depends on what I'm shooting.


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## Mt Spokane Photography (Oct 18, 2018)

I borrowed a card from my 5D MK IV to check out my R, I have a lot of cards, but that one was handy. I do not have any UHS-II cards though, so I educated myself on what the various options are Canon recommended a class V60 or higher to use 4K, so I went ahead and ordered a Delkin V60 class card. There are V90 class cards at twice the price, but buying something faster than the camera can use for twice the price did not seem smart. I'll see how well it does when it gets here from Adorama. I'll always have lots of SD cards around, but if I like higher speed, I'll get a second one, perhaps a different brand to avoid any likelihood of two failing from a common weak point.


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