Minimum focus distance is 3 feet.
On the firmware issue: the newest firmwear only came out on Dec 5th, so you def need to update. It will NOT read or use the filter file until it has the new firmware update.
I’d suggest putting the new firmware .bin on the SD with no filter file. Run the cam through the firmware update routine: hold the shutter button for @3 sec until it beeps and the button glows red and green. Once that’s done, turn the cam off. Plug it into the computer and then drop the filter file into the SDs root directory. When you turn the cam back on, it should use the filter.
Pro tip that I had posted early on: you can create a folder on the SD. I named mine BIN. Then I dropped the 3 Camp Snap .bin files in there, as well as the new .flt files. When you want to change a sim or filter, just copy-drag the file into the root of the SD card. (hold Alt/Opt while dragging)