texaseve wrote:
I was updating software for my D810 and D500 with a card. I used it an erased the stuff on there after using (the updates). My question is, if I have formatted a card in my D810, and then decide I want to use it in a different camera, the D500 or even the Canon I have, does it matter? I usually don't format cards to begin with, I just stick them in the camera and they work fine.
In general, it's good practice to ALWAYS format a card in-camera before starting to save any new images to it. There can be issues switching using them between models and especially between different manufacturers. You've been very lucky, if you haven't had any problems. I've often loaned a card to friends using them Nikon, Pentax, Olympus etc. and they would no longer work properly in my Canon.
I also never "erase" or "move" images off cards. I "copy" them, so the originals remain on the card until I'm sure they have all been copied off successfully and safely. So I'm simply in the habit of formatting every card, every time I install it in a camera. Don't know about Nikon, but my Canon have a user-definable page in the menu... and the very first item on mine in all my cameras is "format card". It takes me about 4 or 5 seconds to insert a card and format it. Formatting does not remove old images... It just marks them as "okay to overwrite".