Hello Tapeworm,

Here are the specs on my card:  SanDisk Extreme CompactFlash, 60MB/s.  The letters UDMA appear in an oval.  There is a diagram of a movie clapper, showing the number 20.

The card is about 8 years old.  It has been used only in my Canon 5D (the original 5D).  I always reformat the card in the camera.  About a year ago, I noticed that the capacity of the card had begun to shrink.  As of November, 2013, the capacity was 22.6 GB.  Now it is 7.81 GB.  I tried reformatting the card in my PC, without success.  Windows explorers sees no files on the card after formatting, nor does the camera.

I see by searching the issue that I am not alone in this problem.  I see a lot of speculation about causes and  remedies, but no reports of success.

Here are my questions:

1.  Is there a utility that will restore the lost capacity of the card?

2.  Is there any other means to restore the lost capacity?

3.  Is this a problem unique to SanDisk cards, or more prevalent with SanDisk cards than with other brands?

4.  What, if anything, could I have done incorrectly in my workflow to cause this loss of capacity?

5.  Does the capacity loss indicate corruption of the card?

6.  What information does SandIDisk have about the issue?

7.  What has SanDisk done about the issue?

A lot of questions, I know, but I’m hoping you can address each of them.

Thanks very much,


Hey John,

I took the card to Samy’s in Santa Barbara yesterday.  They told me the problem is that the original 5D camera can handle only cards of 16 GB or less.  They were familiar with the problem of shrinking capacity with larger cards with this camera.  They reformatted the card in a 5D Mark III at the counter, and it formatted to 32GB.  They warned me that the capacity will shrink again when I next reformat the card in the original 5D.  They were not aware of any utility that could be used in lieu of formatting in a later camera.

So, this does not appear to be a Sandisk problem at all.



Thanks for the update. I’m sure it should prove helpful to others. :smiley: