Corrupted CR2 file out of the camera

[groman]

I have a 7dii bought new 6 months ago- I have gotten three or four files that came off the camera corrupted. Why is this happening and should I worry about it? So far it hasn't seemed to affect any important shots, but I will know I will be dissapointed if it happens to a great shot.

[ebiggs1]

" I move all photos from the card to a file folder on the computer, then into Lightroom for processing."

If you are using LR as you imply, you need to let LR do all the moving copying and importing.  It is a bad idea to do it outside of LR and then edit in LR.  Let LR do it thing, all its thing.

There are a couple things I am beginning to change my mind or thoughts on.  One is always formatting the SD card in the camera.  I have not seen any problems with doing so with the computer. Maybe just luck but no issues so far.  I will say that I use a Windows machine and not a Mac. If I were using a Mac I would never, never use it to format an SD card for any camera.  Mac's are just too finicky.  Secondly, using a card reader instead of the camera.  I mean cheap card readers that you find at Walmart, etc.  They are terrible and nobody should use one in favor of their camera.

[Peter]

This is a part I don't really understand, but SD cards support ERASE command to be able to erase everything at the same time. Probably that's why it is so much faster than doing a normal "low level format" in computer.
I also guess the low level format in camera maps out bad sectors.

A CF works differently and doesn't have low level format in camera.

[groman]

Lots of good information- thanks everyone. I realize the CF card I am using is the one from way back to my 40D, so I'm betting it is getting a bit tired. I think it's time for a new card, which I will format before use and regularly after. Is there any preferences for either CF or SD card?

Thanks again all!

[Waddizzle]

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@Peter wrote:
This is a part I don't really understand, but SD cards support ERASE command to be able to erase everything at the same time. Probably that's why it is so much faster than doing a normal "low level format" in computer.
I also guess the low level format in camera maps out bad sectors.

A CF works differently and doesn't have low level format in camera.

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I have to question what exactly a camera does when it low level formats an SD card.  If you assume a continuous write speed of 33 MB/sec, then it should take 30 seconds to write just 1 GB.  At that rate, then it should take 16 minutes to “low level format” a 32 GB SD card, which is about how long your PC would take to do it.

But, a camera seems able to do it in well under a minute.  And, 16 minutes does not include to Read the test data back.  I think all a camera does is initialize pointers in the storage blocks, and clear any block allocation table.