A corrupted memory card has damaged data that prevents it from performing properly. If a card becomes unreadable, you may not be able to access photos on it.
Memory card corruption often results from human error. Awareness of the main causes can help prevent card corruption from occurring.
Causes of memory card corruption
- Turning off a camera before an image is completely written to the memory card.
- Removing the memory card from a camera while an image is being written to the card.
- Removing the card from a memory card reader while files are still being transferred to a computer.
- Batteries conking out as files are being transferred directly from the camera to a computer. Note: always make sure you have fully charged batteries before transferring images.
- Removing the card from a card reader while folders and files from the card are open on a computer.
- Opening, deleting, renaming or moving files on the card while its contents are open on a computer.
- Using a memory card which has not been formatted in the camera. Use the delete/erase function when needed, however a card should be regularly formatted.
- Formatting a card in a computer instead of the camera. Formatting a memory card in a computer can slow down data processing when it’s used in the camera. With some memory cards, formatting via a computer may result in compatibility and operational problems. [Related reading: Why format a memory card]
- Inserting a second memory card into a card reader before closing and removing the first when viewing images on the card from a computer.
- Taking photos when camera batteries are nearly empty.
- Taking photos too rapidly so the camera can not complete writing one image before starting the next.
- Continually shooting and deleting, shooting and deleting images when the card is full.
- Letting a memory card get too full before downloading the images to a computer or storage device. Cards that are too full may overwrite the card headers.
- Using a memory card from one camera in a different camera without formatting it in the new camera first.
Memory card “fixes”
If your memory card becomes corrupted, stop using it immediately. Do not format or attempt to delete any images from it.
If the card is still readable, try retrieving the files using an image recovery program. If the card is unreadable in the camera, try retrieving images by using a memory card reader.
Some recovery programs recover a wider range of files than others. They recover images, documents, mail, video, music and a variety of file formats such as bitmap, sound, animation, 2D/3D vector graphics, word processor, database and spreadsheet files.
If you’ve lost images as well as video and audio files make sure the program you use is capable of dealing with each format you hope to recover. Image recovery programs can be downloaded from the developer’s website, usually with a 15 – 30 day free trial period.
When images can’t be recovered
If you can’t retrieve images on your own and the photos are of great importance, send the card to an Image Recovery Lab. Many memory card manufacturers offer recovery service…for a fee.
If you can part with your photos, it may be less expensive to purchase a new memory card rather than send the corrupted one to a lab. If your card is still on warranty, the manufacturer may attempt photo recovery without charge.
Tip: Make sure your Secured Digital memory card is unlocked - If you’re using a SD or SDHC card, make sure the small write-protection switch on the left side near the top of the card is not enabled. Sometimes a card gets locked when inserting it into the camera or card reader. Gently slide the write-protection switch down to unlock it.