I have been shooting on my Canon 5d Mk4 utilizing both slots - Compact Flash and SD for couple of months now but did not have time to process my pictures so haven't really removed any of the cards from the camera until this morning.
I needed to download couple of pics for one project I have been working on so I removed my CF card, downloaded roughly 15 pics and placed it back to the camera (so no formatting, no deleting, nothing).
Today I continued with my project, took roughly 20 pics and when reviewing them I have noticed that I can see only those 20 pics, while the rest was not there (couple hundred pics).
So I removed CF card and checked what is on SD card and realized there are only those 20 pics from today.
Then I placed back CF card and removed SD card and noticed there are all remaining pics (those couple hundred) but those 20 from SD card are not there.
When checking the setup of my camera, my primary card to which the camera is supposed to write is CF card and I was hoping to have a back-up on SD card.
This does not seem to be the case which is absolutely weird.
So my 2 questions:
1. How is it possible that today the camera started to record today's pics to SD card if my primary card for recording is CF card?
2. How is it possible that SD card is not just a copy of CF?