Faced with the likelihood of finding critter friends much more confiding than in most other places, I opted to split my reach and increase my speed with a 70-200mm f2.8 GM II and 2X teleconverter shortly before I departed for this leg of the journey.
Out for a last-minute accessory just before I left the ant farm, I got into a conversation with a salesman friend who’s been dealing Sony since their KM takeover days. We were talking about the 70-200+2X compared to the 100-400mm GM, agreeing that they’re pretty much equals—except for the baked-in sharpening on the 100-400mm.
He mentioned that most of his customers, though, get the 1.4X with the 70-200 because there’s no perceptible performance dip. This concurred with multiple sources I’d read online, one of whom claimed that the 1.4X combo cropped was as good as the 2X combo. Convinced by my friend, I grabbed a 1.4X.
For most birding venues, 280mm is way too short. Here in Galapagos, it’s perfect. And now having compared shots with both teleconverters, I see that my friend and the online reviewers are correct, with an exclamation point. Nothing wrong with the zoom+2X, mind you, it’s just that the 1.4X combo is really, really good, evoking thoughts of the SL 90-280mm. Yep, that good. And about 700 grams lighter.
The bonus is that close-up shots with the 1.4X, which takes the lens to around 1:2.2, are near-prime quality. My copy of the 2X isn’t all that impressive anywhere near MFD. Some people claim there’s a sample variation issue with the 2X, but mine does just fine at longer distances.
All of this leaves me hoping for either a refresh of the aging 100-400mm GM or maybe a 100-500mm GM (since Sony has a history of directly challenging Canon). Absent any new long options, I won’t mind eventually adding a 200-600mm G to the arsenal, as it’s probably the best bang for the buck on the market these days.
Whatever the case, I head out the door on shooting forays pretty happily these days . . .

a7cII/70-200mm f2.8 GM II/1.4X . . .