Hi! Am a new member and am in a similar dilemma as yours since the 75-300 is reasonably priced as compared to 100-400.


Am contemplating 55-250 too; but reading various reviews and posts by others; is making my already dizzy head.... spin more!!!


If you get any response which helps you on this matter, please let me know.


I too was contemplating using a reasonably priced lens with a converter, but since I don't know much about these thing, am at a loss. Reading posts & reviews surely helps, but will take time to digest I guess.