I’ve recently learned a lot of beginner, and so beginner photographers use their digital camera’s memory card as a permanent storage device. In doing so, when out on a shooting day, they check the camera’s LCD screen after each shot to see if they like it. (This is called chimping.). And if they don’t like the photograph, for whatever reason, they press the camera’s delete button and assume the photo is history - gone - is no more!! And then they go back to capturing more and more digital images on their camera’s memory card.
While this is a common practice, it is not a good idea. It’s not a matter of if a digital camera’s memory card will fail, but when. And deleting an image in-camera off the memory card does not really delete the offending photograph.
No??? What does it do??
So what is the preferred process???
IMO, digital camera memory cards are not permanent storage devices for your digital photos. A simplistic description of a digital camera is “a small computer with a hunk of glass on the front of it”.
A digital camera doesn’t capture/create a photograph. It creates a digital image file consisting of 1s and 0s - a computer data file. At its most basic, a digital image is a computer file. And like all computer files, they are subject to corruption.
Your camera’s memory card records the digital computer file your camera body creates. On the memory card is a File Allocation Table (FAT). This FAT records where on the memory card each image is stored. A pointer is created to each image. When you playback the image on the LCD screen, the FAT locates the image file and displays a JPEG version of the data on the LCD screen, whether the file type is JPEG or RAW. When a photographer deletes an image in-camera from the memory card only the FAT pointer is deleted - not the actual digital image file. As the photographer keeps adding new images to the memory card the odds of a new image overwriting an old digital image data file increases. Eventually, depending on the storage capacity of a memory card, a new image data file may not completely overwrite an old one. Then you end up with two corrupted digital image files, or maybe the whole memory card may become corrupt. And therefore useless.
What’s the solution??
When you return from your photo shoot, transfer all your digital image files to a computer hard drive, or an external hard drive. Check the drive to ensure all the images are present and safe. Then put the memory card back in the camera, locate the camera’s Format command and format the memory card in camera. The camera’s Format process completely erases all the FAT and all the digital data files from the memory card.
Do NOT format a digital camera memory card in any computer - ever!!
Now you are ready for your next fantastic photo outing where you can start all over again creating photographic master pieces.
Oh yes, create a second copy of all your digital image files stored on your computer’s internal hard drive on a second external hard drive. And if you originally transferred your digital image data files to an external hard drive, copy these files to a second external hard drive - just to be safe.