f stop reading: f00 when using 1.4 extender between EOS R3 and 400mm f/2.8
Using Canon R3 with 2.0 extender and 400mm f/2.8 lens, works fine. When switching to 1.4 extender, f stop reading is f00 and nothing works. No camera functions work. This problem did NOT occur previously when using the 1.4 extender. Any thoughts on w...