If you are a pro, do you use two card slots for backup? Locked

pedz wrote:

I don't want to start the debate if the EOS R is a pro body or not. I'm fine declaring that it is not. But one of the nits against it is it has only one card slot and "no pro would ever use it" is stated emphatically very often. So, I'm curious.

I'm an avid amateur that might make a few dollars here and there on my photography and I have a nice job to pay for my toys. The few professional photographers I've known tended to be on an extremely tight budget and had consumer grade bodies that were a few years old. I've also got this hint from some YouTube videos.

I'm curious if you use a body with dual card slots and you have it set up to copy each image to both cards.

I think if I was really worried, I would cycle through a lot of small cards and, if I could afford it, have a pocket PC that could backup the cards as they got full to safer storage rather than trusting the camera to do the backup. The camera doing the backup still has a single point of failure and a firmware glitch in the camera seems more likely than today's cards having the glitch. To rephrase, it seems like both copies the camera is making are going to get damaged more often than just one copy.

As others here mentioned... if you do the research you will find that 90% of the time (or some high number like that) cards do not simply fail on their own. They fall apart, or due to the constant load you put on them (clicking them in and out, placing them in your computer etc) they end up degrading physically. I have only had cards fail on me on 2 occasions and that was after years of use. So after learning this fact, I simply never take the card out of my camera unless I have to. So with a 64 GB card in there you can imagine that I rarely have to take it out if every.

Since the R also charges via USB-C (with my mac's adapter too), I simply use my MBP's cable to transfer files and charge the camera at the same time. If i were to ever do a wedding I might approach things a little differently. Would probably have 2 bodies and make sure I have a mix of shots on both bodies so that any card loss would not mean a complete wedding gone. 
Invest in good cards. 
FYI: The two cards that failed on me failed in a sony A7II. It started complaining about writing to the card, and only the last few images were lost, the rest was recoverable. Unfortunately since I couldn't review the images in camera either I actually redid the shoot. Client got extra photos as bonus.