Today’s Question: I have always heard that you can “damage” a memory card by deleting images from it either in your camera or when in a card reader hooked up to your computer. Because of this I never delete images from my cards. I download the images first and then reformat the entire card. Would you please clarify the best procedure to follow and if deleting directly from memory cards is advisable?
Tim’s Quick Answer: You won’t damage a media card by deleting photos from that card, either in the camera or using your computer. The risk of any other problems (such as corrupted images) is also exceedingly small. There is no need to be worried about deleting photos directly from a media card.
More Detail: I’ve been hearing about the recommendation to never delete photos directly from a media card for quite a long time. While there have been some issues with certain cameras creating corrupted images, there is no need to worry about deleting photos directly from a media card. In fact, when I have asked engineers from storage media companies about this issue, they generally roll their eyes and chuckle.
Flash memory does have a limitation in terms of the maximum number of write operations that can be performed before the flash memory fails. This may be one of the reasons there are so many misconceptions about the risks of performing certain tasks with media cards.
However, modern media cards employ rather sophisticated systems to manage the storage and ensure there are no problems with the media or the files stored on that media. For example, most cards will balance out which portions of the card are used, so that you don’t wear out the memory at the “beginning” of the card while the memory at the “end” of the card remains unused.
Of course, while there is no need to worry about deleting photos directly from a media card, there are reasons you might want to avoid doing so. First, if you’re reviewing and deleting photos on your camera, you might not be paying attention to what is happening beyond the camera, and you might miss a good photo opportunity. Second, I think it is better to review your photos on a larger computer monitor rather than on a small LCD display on the back of the camera. But fear of damaging a card does not need to be a consideration.
Having said all that, it is a good idea to format the media card in your camera after you are finished downloading the photos to your computer (and backing up those photos). This is simply to refresh the file allocation table (the “table of contents” on the card), which can help reduce the risk of any corruption creeping in over time. In addition, formatting is generally quite a bit faster than deleting all images on the card.