« on: June 17, 2014, 10:48:18 AM »
you're not going to see a significant difference between 5.6 and 6.3 for any of your issues though.
1. every bit worse hurts ... anything from f/5.6 onward is twilight zone anyways ;-)
2. especially considering how ALL manufacturers LIE about focal lengths and f-stops ... in reality f/5.6 often really means T/6.2 and f/6.3 means T/7.9 ... or so
Not necessarily. What is the T-stop of of the 35 f/2 IS? T/2. What is the T-stop of the 24-70 f/2.8 II? T/3. Modern coatings are much better than they were a decade ago. It's time for you to sell the 55-250 and buy the 70-200 f/2.8 IS II because that is what you really want.