Compact Flash Cards - Lost storage?

Hello POTN,

I have 2 16GB SanDisk Extreme Compact Flash cards and they arent showing their full capacity when inserted into my 7d anymore. When I first got them, they would show '999' on the top of the camera in the storage space field. After letting a buddy of mine borrow them, one shows 697 and the other 756. I deleted everything off of the cards and there was nothing on them. While my buddy was borrowing my cards, he gave me a 32GB card to hold onto while he used mine. (I helped him with a gig and let him hold my cards so he could take them home and get all of the footage.) That 32GB card he gave me only showed 320 something storage and never understood it, but now that I have mine back I feel the problem may be the settings in his camera. He has a t2i and I believe he has Magic Lantern on his firmware. If anyone knows how to I guess 'reset' these CF cards please point me in the direction of the process. I haven't seen anything online. Thanks in advance!!

Put 'em in your computer and check their status. It's possible his camera doesn't support cards of over 8 GB (I can't recall if the T2i did originally or if it got a firmware update to permit that); if that's so and he formatted the cards in-camera, the camera would have repartitioned all the cards to 8 GB.

Jon wrote in post #15733344
Put 'em in your computer and check their status. .

Thanks for your reply but can you explain this a bit further? I put them into my computer through my camera the way I normally upload photos but didnt see anything special. Im not exactly sure what to look for...

Do you use a card reader? (You should, for very many reasons, not least being able to perform first aid on ailing cards.) Through a card reader you'll be able to see the card's available space. Card readers can be inexpensive and are generally faster than direct download from your camera.

Format the card through your camera settings. If that doesn't work, format through your computer. When I inserted a 16GB card into my Rebel XT and formatted it, the card showed 8GB. Formatting the card in my 5DII reverted it back to 16GB.

Thanks guys, I will look-up how to format these cards as I have never done so, and see what happens.

Just back up your data on the card first. It will erase your data. I always format every time I erase a card, just to keep them clean.

Jon wrote in post #15733896
Do you use a card reader? (You should, for very many reasons, not least being able to perform first aid on ailing cards.) Through a card reader you'll be able to see the card's available space. Card readers can be inexpensive and are generally faster than direct download from your camera.

No I dont use a card reader. I always thought that downloading straight from the camera is the fastest and gives you the best quality.

D. Vance wrote in post #15735476
Just back up your data on the card first.

Please explain. Is there an option to do this when you are using EOS Utility on the computer?

TimHphotovideo wrote in post #15735488
Please explain. Is there an option to do this when you are using EOS Utility on the computer?

No, I always use a card reader. It is much faster, and they are quite cheap; Targus ones are around $13 at Walmart, and even those will be much faster than running the cable from your camera. Drag the pictures off your card into a folder on your computer/hard drive, and once your data is safe, place the card in your camera, and go into the 'Menu' on your camera. It is on the first yellow colored menu, I believe. The option is 'Format Card'. It will erase all the data on the card, and it cleans it better than a computer does.

When using a card reader, remember to 'safely eject/remove hardware' to stop the processes before removing the reader. This helps prevent corruption of data.

D. Vance wrote in post #15735504
No, I always use a card reader. It is much faster, and they are quite cheap; Targus ones are around $13 at Walmart, and even those will be much faster than running the cable from your camera. Drag the pictures off your card into a folder on your computer/hard drive, and once your data is safe, place the card in your camera, and go into the 'Menu' on your camera. It is on the first yellow colored menu, I believe. The option is 'Format Card'. It will erase all the data on the card, and it cleans it better than a computer does.

When using a card reader, remember to 'safely eject/remove hardware' to stop the processes before removing the reader. This helps prevent corruption of data.

I see, but with this, does that erase the shot count on my camera? Currently, my camera shows how many shots have been taken with it. Something I want to keep note of when I sell it to upgrade to full frame. I have heard that erasing data in-camera will erase the total count and start from 0? If so I guess I have no choice. I need the full amount of space from my cards...

D. Vance wrote in post #15735504
The option is 'Format Card'. It will erase all the data on the card, and it cleans it better than a computer does.

When using a card reader, remember to 'safely eject/remove hardware' to stop the processes before removing the reader. This helps prevent corruption of data.

I never knew that computers could clean your card. Or maybe I never noticed it. I would just download the pictures and delete them one by one from my camera... very time consuming, but again, it is because I remember hearing this was the only way to keep your cameras shutter count for the 7d.

TimHphotovideo wrote in post #15735483
No I dont use a card reader. I always thought that downloading straight from the camera is the fastest and gives you the best quality.

Nope, not fastest. And electrons don't flow across the USB cable from your camera any different than they do from a card reader (except most card readers can steal them off the card faster than your camera will let them). As an added bonus to using the card reader, you don't need to have the camera turned on (using battery life) and you don't risk snagging the USB cable and sending your camera crashing to the floor.

Here is one of many videos that might help.

http://youtu.be/rdMHyO​OPKkQ

kersty wrote in post #15741917
Here is one of many videos that might help.

http://youtu.be/rdMHyO​OPKkQ

TY!!