| Re: AF or MF?
I'm afraid all I can say is 'throw the converter away'. You need a really good quality lens to successfully take a x2 and, sorry to say, the 75-300 just isn't up to it. I did manage to use a 1.4x on the newer 70-300 but I wasn't totally happy with the quality of my photos so I gave up with it.
AI (artificial intelligence) Servo automatically locks onto a moving subject and holds the focus by automatically adjusting itself by continually refocusing. It works fine on distant subjects where there is a fair bit of spare depth of field distance but struggles to hold focus where the depth of field is shallow.
Alternatively AI Focus focuses on a still subject but then switches to AI Servo mode if the subject (or photographer) starts to move.
For best results, from static subjects under the right conditions, I always prefer the One Shot setting as there is no chance of the camera deciding to try to alter focus.
So experiment with the other focusing options then choose the best one for each photo.
When you have sorted out this little problem, have a think and experiment about the different exposure alternatives. Nowadays I mostly use the spot or partial metering option and often once I have worked out the best settings (subject to operator error) I use the manual controls. Never the Full Auto controls!  |