Hi, Am a partial newby sort of 1/4 the way up the learning curve. I have a AF-S Nikkor 55-300 1:4,5-5,6. I live in Africa and have bountiful access to wildlife. I need advice. I don't have the funds to buy a 500 or 600 lens and intend to use a convertor I am aware of the quality restrictions but will live with them until a decent lens becomes affordable. My question is (and here I know zero) what convertor should I get??? any advice is appreciated.