So I've been shooting with my Olympus E620 for about 6 months now, primarily with the 70-300mm f4-5.6 lens attached to it and have been pretty happy with the results I have been getting (especially when the lighting is good). I feel pretty confident in my use of this lens now, and have recently been looking at my options for my next lens.
Note I primarily shoot birds (that is, 98% of the time!).
Now the dilemma I am currently facing is this: I have been looking at purchasing the 50-200SWD f2.8-3.5 lens and adding the EC-14 teleconverter, which would give me very similar length the the 70-300mm with improved image quality. I would also have the option of removing the teleconverter for those rare occasions I can get close enough to birds not to need the extra focal length.
However, since Sigma's recent announcement to drop the 4/3rds mount support of their larger focal length lens (the new 150-500mm lens) I am beginning to think I might be better off looking for a Sigma 50-500mm f4-6.3 Oly mount lens while I still have the opportunity.
Obviously the lens is slower, heavier, and not up to the same build quality as the Oly combo (no weather sealing etc).. but the focal length (1000mm equivalent!) is certainly very appealing for the price tag (circa $1,400).
I've read countless articles/threads/forums about the pros and cons of both of the above set ups, and was wondering if anyone here has any experiences with either or might like to weigh in with some comments?