topic Corrupted CR2 file out of the camera in EOS DSLR & Mirrorless Cameras

Corrupted CR2 file out of the camera

groman — Wed, 16 May 2018 18:56:37 GMT

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.

Re: Corrupted CR2 file out of the camera

Ray-uk — Wed, 16 May 2018 20:01:57 GMT

Are you using a full sized SD and not a micro SD with an adaptor.

Are you using a cheap memory card.

Have you formatted the memory card in the camera.

Are you transferring your picture files from your camera via a cable or with a card reader.

Re: Corrupted CR2 file out of the camera

groman — Wed, 16 May 2018 20:14:02 GMT

I am using a Lexar Pro 800x 16gb CF card, and transferring pictures via cable. I have taken about 9,000 pics and only a few have been like this. I can't say I have actually formatted the card- I move all photos from the card to a file folder on the computer, then into Lightroom for processing. The corrupted files show up in the folder after the initial download.

Thanks for getting back to me.

Re: Corrupted CR2 file out of the camera

Ray-uk — Thu, 17 May 2018 10:40:43 GMT

If the files show up as corrupted after you download them but appear alright if you view them on the camera then that suggests you probably have have either a faulty cable or the connection is breaking at times.

I have found that a good quality card card reader is easier and more reliable than using a cable.

The card should be formatted in the camera, the instruction manual tells you that. I would definitely recommend that you format the card in the camera every time after you have downloaded the files and avoid deleting individual files as you shoot.

Re: Corrupted CR2 file out of the camera

ebiggs1 — Thu, 17 May 2018 16:46:56 GMT

" 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.

Re: Corrupted CR2 file out of the camera

groman — Thu, 17 May 2018 17:46:30 GMT

Thanks very much- I will try formatting the card in camera. I regularly delet shots directly from the camera- didn't realize it was a bad idea.

Re: Corrupted CR2 file out of the camera

ebiggs1 — Fri, 18 May 2018 15:14:05 GMT

"I regularly delet shots directly from the camera- didn't realize it was a bad idea."

They say it is but I have not experienced any issues doing it.

Re: Corrupted CR2 file out of the camera

Peter — Fri, 18 May 2018 15:33:18 GMT

@groman wrote:
Thanks very much- I will try formatting the card in camera. I regularly delet shots directly from the camera- didn't realize it was a bad idea.

It seems to be "fact" without proof. When you delete at file, you just change the address to the file, so it shouldn't give you any problem. With that said also I format the card in the camera after each photo session. Actually even low level formatting the SD card.

Low level formatting the card will decrease the life of the card, but if a card has 100,000 write cycles as a limit, how many years will it survive only by low level formatting each day....

Re: Corrupted CR2 file out of the camera

Peter — Fri, 18 May 2018 15:52:38 GMT

My last failure was 2008. 40D and Transcend. All pictures left on card. Just card error in camera.

2006 I got the whole card destroyed. S3 IS and SanDisk.

Re: Corrupted CR2 file out of the camera

ebiggs1 — Fri, 18 May 2018 16:05:58 GMT

It appears the in camera low-level format overwrites the entire card. The normal format just rewrites the system part of the FAT32 partition, leaving data intact. The low level format sets the whole partition data to zero.

I agree it is not good practice to low level format each time since those are write operations and each memory cell on your SD card only has so many writes to it before it becomes unusable. If you decide to format SD cards in your computer, make sure that you check the “Quick Format” and NOT the low level format.

Re: Corrupted CR2 file out of the camera

Waddizzle — Fri, 18 May 2018 22:55:51 GMT

@groman wrote:
Thanks very much- I will try formatting the card in camera. I regularly delet shots directly from the camera- didn't realize it was a bad idea.

It could be bad if you have never formatted the card yourself. New cards should always be low level formatted prior to first use. New cards are not pre-formatted. They are tested during production, and what seems like formatting is actually residue from production testing.

I have never had problems deleting files in the camera, but it is usually the most recent shot that I took. Deleting files just erases the entry in the storage medium’s directory. The actual data is not overwritten or erased, but it can be if you write new data to the card.

As far as low level formatting a camera goes, I have to question what it is that the camera does when it supposedly performs a low level format, because the camera does it WAY too quickly. A computer spends a LOT more time performing a low level format on a memory card than your average camera. Use a card reader and try it some time, but do not use a high capacity card if you do.

I do not think cameras actually test every storage bit. I think they just go through and erase the pointers in storage blocks. The file directory points to the first storage block of a file, and at the end of each block there is a pointer to the next storage block. This continues until the final storage block, which will have an “End Of File” code, instead of a pointer. I think cameras simply erase the pointers, which makes it near impossible to recreate the storage path of a file.

Re: Corrupted CR2 file out of the camera

Peter — Sat, 19 May 2018 07:16:05 GMT

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.

Re: Corrupted CR2 file out of the camera

groman — Sat, 19 May 2018 15:15:46 GMT

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!

Re: Corrupted CR2 file out of the camera

Waddizzle — Sat, 19 May 2018 22:08:26 GMT

@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.

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.