i really really do not understand what is the advantage of DO in a tiny little converter?
I thought DO is dead since 70-300 DO 3.5-5.6 lens.
ditto, shaving 100g off a 325g converter is a big % by itself, but nothing when you add on a 5kg lens on the other end.
maybe if they can make the tc pair well with some not-the-best lenses, it could actually correct some CA from the original lens? (ie, lens+tc gives better images than lens by itself, rather than worse as is normally the case). (if this is even possible). (would make the most sense for built-in TCs)
and it's not dead besides the 70-300DO and the 400f4DO, there were other patents here a few months ago for some wide-prime-DO lenses (which do make more sense in a reverse-tele Wide Lens). but for us consumers it may as well be dead until they make it, true.
and some specs for those interested:
400 f5.6 - ~1.2kg - â‚¬1200
400 f4 DO - ~2kg - â‚¬6k
400 f2.8 ii - ~3.9kg - â‚¬10k
70-300 - 600g - â‚¬480
70-300DO - 720g - â‚¬1300
70-300L - 1050g - â‚¬1350
so you can't really tell how well the DO helps with weight and price because there's no direct comparison, the prime is bang in between the faster/slower versions, but it's definitely the shortest. (and the 400 f2.8 i was a lot cheaper than 10k, i think less than the f4 DO if anyone can confirm?)
same with the zoom, it's a bit heavier than the plain, and well below the L in weight, but the price is almost the same as the L for a lot lower IQ. it is a lot shorter than both though (in retracted at least).