I am choosing between whether to buy a Canon or Olympus DSLR for birding. I am wondering why so many people here choose Canon when Canon crop factor is 1.5x while Olympus is 2X. It is about 1.4 times extra and wouldn't it be wonderful for birding? Why do birders here like to choose Canon DSLR and for the sake of extending their reach, they buy teleconverter which causes them to lose f-stop. Why don't they use Olympus DSLR instead. I sure they is a reason but I cannot find the reason anywhere.