- Why would I need a CFexpress Type B? What can they do that the regular SD Card UHS-II can't? I have no interest in shooting ProRes mode by the way, just wanting to have the best quality 4K Video
- If I put both a UHS-II card and a CFexpress Type B, does the camera use the faster one first and then switch to the slower one when it's full or you can only select 1 card for shooting?
This depends on how you have the camera set up.
https://fujifilm-dsc.com/en/manual/x-h2s/menu_setup/save_data_set-up/#card_slot_setting_still_image
For stills you can choose to save the same files to both cards - shoot raw to one card and jpeg to the other or save all files to one card (and overflow to the other).
If you choose sequential mode then you set which card the camera uses first - it doesn't intelligently choose the faster card.
PS: I currently have a UHS-I (not 2) SanDisk Extreme PRO 256GB with a rating of 200MB/S, not sure if I am hurting my video recording performance by using a UHS-1 card rather than a UHS-II
Thoughts?
To get the best out of the camera - high quality video and fast continuous bursts its worth getting faster cards - your UHS-I card saves at well under 100MB/sec (Sandisk only guarantees continuous 30MB/sec).
That 200MB/sec headline number is only for copying files from card to computer - and then only if you have a proprietary card reader that can handle the speed.
UHS-II cards would help - but to get the best out of the camera and give the ability to use both card slots its worth getting a CF Express Type B.