Sharing 1 SD card for 2 Cameras

scorrpio wrote:

It is easier to use cross-brand - i.e. I had no issues using a card from a Nikon in my Canon, as different brands generally use different folder structure and file naming. Same card between two Canon is asking for trouble and confusion. I would not do it.

Or, at least, format the card when switching it to another camera.

what you're going to encounter is fairly logical, but potentially annoying.

The Canon numbering system depends on which file numbering more you're in, most people use continuous.  In that mode the camera stores the image number of the last image shot in memory.  It then compares that number to the highest number it sees on the SD card, selects the largest of those two numbers, and adds one for the next shot, which then gets stored in memory (as well as on the card).  this prevents you from repeating image numbers later on if you put the card into another camera and advance the image numbers on the card, then bring it back to the original camera again.

However, if you delete all the images off the card and put it in another camera, since it has no image number on the card to read it will use the image number stored in memory and add one to that.  As you can see, this will quickly get out of sync between all the cameras if you delete images off the card after each use.

One way around this is to rename the images as you read them off the card, by adding the name of the camera into the image number.  As long as you always delete the images before putting the card into a different camera, this method will work OK because each camera will remember its last shot number from memory and continue from there.  But, if you forget to delete them, then it will pick up with one of the other camera's image numbers if its image numbers are higher, and you'll likely get confused and not realize it happened until you go to download.

So I think you can see that keeping a single card for each camera is probably the easiest method of all, but you will still have to rename images when downloading to avoid having 3 different copies of IMG_1234 for example.

A long time ago ZoomBrowser used to append a folder number to the image number during download, which worked OK if you set each camera different folder numbers far enough apart.  But I think that feature disappeared many years ago, and then I stopped using ZoomBrowser altogether.