Originally Posted by UdubBadger
hahaha, yeah it makes sense. maybe the 2.8 is a better choice though since I could run it on my 40D and use the 1.6x crop to give me some more zoom on it.
Would that work with the 1.4x converter? Does it change the f stops like the 2x?
yes it does, but nowhere near as drastic.
there is still some quality drop at the edges as a result of it, but not as bad as the 2x. so you might stop down a little just to tidy it up but not as much as you might with the 2x
but also remember, a 200mm is still a 200 mm on a crop or a full frame, it's
just the image is cropped. It's easy to forget i find.
your F stop would be a 4 constant, which isn't bad to play with compared to a 5.6. but the other way to look at it is, even with the furthest reaches of the 100-400, you're still shooting a 5.6, but at least at 100, it's about an f4, and still able to do that full zoom range and still keep great sharpness.
the big winner in my eyes though is the ability to shoot between 70-200 at f2.8. anything after that is just bonus that you want to play with. I find you have to work with the 70-200 F4 to get nice bukah, where the 2.8 will do it with almost any picture with minimal effort. I think that's where the money really is in the long run. Unless you get into wildlife. then i'd just say the 100-400, which you could put a 1.4 tc on and run on most cameras.
the 100-400 is the cheapest super tele your next option is start buying primes which will get into the several thousand range. So, before buying with passion, assess what your uses for it will be and go by that. If all you're doing is portrait work and never venturing into the woods, forget about the 100-400, it will be useless for you.