With my Evo Pro 2 v1, I typically store stills on a 32gb microsd card. But the thought occurred to me that perhaps internal storage may be more reliable. Unlike my full frame camera, the drone doesn't have a back-up SD slot. Does anybody know what the capacity is of the internal storage? I couldn't find it in the manual anywhere.
It says it in the marketing materials on their website; 8GB, you can also see the remaining capacity after you format the internal storage. There's no way I would use the internal storage over a microSD card, the internal storage is mainly just an emergency backup in case you took off and forgot to put a memory card in it or forgot to bring a memory card. 8GB can go pretty quickly when filming video, its a PITA to get the footage downloaded from the internal storage when the time comes (need a USB-C cable, the drone must be turned on, you have to remove the gimbal protector before turning it on, its slower to copy than from a microSD, etc, etc.). Even the photography buffer takes longer to clear when using the internal storage so the IO bus for the internal storage must be slower than the microSD card.
I have flown probably over 1,000 miles since 2014 when I got my first drone and I have used
SanDisk Extreme Pro microSD cards in every drone I've ever owned and not once after hundreds of commercial jobs have I ever lost footage stored on the card. All of my regular cameras have dual card slots as well, and I always configure my cameras to use dual slot recording for both photos and videos, but with drones I've just had to give up on expecting redundancy.
If I happen to have filmed some irreplaceable type of footage such as a racer crossing the finish line first then what I do is land the drone as soon as possible, I insert the microSD card into an SD card adapter, I turn on the write protect feature of the adapter, and I get the footage copied off and backed up right there on location via a laptop and external HD; that way I have 3 copies of the footage before ever leaving the site.