There are two ways to format memory cards in the Nikon D850. One method is obvious. The other is a little less so but also quicker.
And it’s worth mentioning upfront that even though it’s quite possible to format memory cards using a computer, it’s generally best practice to format memory cards in the camera they’ll be used in. That’s true with any digital camera. It lets the camera set the card up with the filesystem and folder hierarchy that it needs and expects and reduces the risk of problems to do with the memory card.
So here are the two methods available on the Nikon D850.
Method #1: Using the Menu
First, the obvious one, using the menu:
- Press the menu button on the back of the camera (top left)
- Move the cursor down to the Setup menu item (the wrench icon)
- Press the right side of the selector to Format Memory Card and then press right again.
- You can then select whether to format the XQD card or the SD card.  You have to do one at a time–you can’t do both simultaneously.
Method #2: Using the Quick-Format Buttons
The D850 cameras also offer an even quicker option for formatting the memory cards, although it’s not quite so obvious how to use it.
There are two buttons to look for: one on the top and another on the back. They have a red “Format” label next to them.
The one on top is next to the ISO button, near the shutter button.
The one on the back is the Delete button, which has a trash can / rubbish bin icon. It’s at the top left on the back of the camera.
There are two tricks to using these. The first is to use them together, simultaneously.
- Press both of the red Format buttons together and hold them down for a couple of seconds until the top LCD screen shows a flashing ‘For’ (for format). The exposure count and memory card slot indicator will also be blinking.
- Release the buttons.
- If you only have one of the two memory card slots filled, it’ll automatically detect that. If you have cards in both slots, it’ll default to whichever you’ve designated as the primary slot. It doesn’t show you which slot is active on the back screen–instead, it’s with the tiny icons at the right of the small screen on top of the camera.
- You can manually choose which card to format by rotating the main command dial on the back panel.
The second trick is that you need to press them together again. If you don’t, it won’t have formatted anything. You don’t need to hold them this time–it reacts immediately.
If you want to cancel without formatting, press any other button or the shutter. It will also cancel automatically if you haven’t selected anything within five seconds.
Things Worth Knowing
The Nikon D850 has two memory card slots, one of which is an XQD memory card slot, and the other is an SD card slot. In December 2020, Nikon issued new firmware for the D850 that made the XQD slot compatible with CFexpress B cards. It’s firmware version C:Ver.1.20. I have more detail on that here and a guide to checking and updating the Nikon D850’s firmware here.
After that firmware upgrade, and even if you’re using a CFexpress B card, the camera’s menu system and top screen still refer to it as the XQD card.
It’s best practice to format the memory cards in the camera, not in your computer. That’s true of any digital camera. It reduces the risk of file system corruption that can lead to memory card errors. Formatting in the camera lets the camera set the card up with the folder system and filesystem it needs and expects.
You have some control over managing how the memory cards in the D850 are used. You can treat them as sequential memory so that when one card fills up it automatically switches over to the next one. You can copy to both simultaneously to create a mirrored backup version. Or you can send image files to one and video files to another. I have a more detailed post on that here.
You can also copy from one memory card to another in the D850. I have a post on how to do that here.
- The menu system refers to XQD cards regardless of whether you’re using an XQD or CFexpress B card. More on that below.