I am using the Canon 5D Mk4 mounted with a Canon 400mm f5.6 L lens ( as much as I want to carry nowadays}. My question is: Would it be better IQ wise to crop the image as opposed to using the 1.4 mk 2 TC. Although I love the 5D Mk4 I miss the 1.6 crop of the 7D mk2. The problem we have in the UK is that generally we are not able to get as close to birds as you seem to in the US. My thinking is that by using a TC I would be getting more pixels on the bird if it were some distance off; the trade off being a slight loss of IQ.
Regarding the 1.4 TC I have read that the Mk3 1.4 will allow more focus points at f8 than the mk2 on this camera body. If this is the case would it be worth my money to get a MK3 1.4?
Thanks in advance.