mget `*.*` doesn't work

I want to download all files in a folder with ftp. But mget *.* isn't accepted. Here is the terminal output:

ftp> ls
200 PORT command successful
150 Directory listing for /DCIM/Camera/
-rw-rw-rw- 1 system system 0 Jun 16 17:46 .escheck.tmp
-rw-rw-rw- 1 system system 164140486 Aug 26 19:47 VID_20180826_194513130.mp4
-rw-rw-rw- 1 system system 1624705 Aug 28 19:11 IMG_20180828_191133828.jpg
-rw-rw-rw- 1 system system 1426824 Aug 28 19:14 IMG_20180828_191424499.jpg
-rw-rw-rw- 1 system system 1166878 Aug 28 19:17 IMG_20180828_191700733.jpg
-rw-rw-rw- 1 system system 1372256 Aug 28 19:52 IMG_20180828_195257123.jpg
 ...
226 Directory send OK.
ftp> prompt
Interactive mode off.
ftp> mget *.*
local: *.* remote: *.*
200 PORT command successful
550 Requested action not taken. /DCIM/Camera/*.* : file does not exist

Everywhere I looked, * was a valid wildcard for all filenames. What am I missing here?