I got myself a FH20 Red Lumix Panasonic Camera. This camera will support SDXC, and as well supports backward versions of the SD cards. So, I wondered, what happens if I take a Sd card, (pre-SDHC) which is a 256MB card (less than 1GB), format it on the PC as exFAT, and put it in the camera. I guess I was hoping that the camera would just use it, but I was wrong. The camera said the memory card was not properly formatted, and do I want to format it?
So, doing some further research, I find that the SD cards each have a different supported format. The SD card should only allow a FAT16 file system, and if you format the SD card with either the camera or the SD Card Association utility, it will format as FAT16. If you have a SDHC card, the file system must be FAT32, and SDXC requires exFAT. At least for Panasonic, there is no fooling the camera.
Now Amazon has 64GB Sandisk SDXC cards for $200+tax+ship, which is really cheap right now, yet for me it is too pricey for me to do my R&D. I really want to see what the OEM parms look like and to see if the formatting by the camera is any different from what the OS would do. I guess I have to wait until I can get my hands on one of these cards.