neuroanatomist said:neonlight said:A 500 f/5.6 needs a 90mm front element. A 600 f/6.3 needs 95mm. Could this lens could be a 150-500 f/5.6 with extender? Although it might be a 200-600 f/something-f/6.3 that won't be very unique... and a 600 f/5.6 will cost too much.
I don't see Canon coming out with an f/6.3 zoom lens for dSLRs, given their oft-stated requirement for f/5.6 to support AF.
Right. So that leaves us with...
- Something - 500mm f/5.6 -- the more reasonable Nikon-like offering that would keep the front element small and the price down (somewhat)
- Something - 600mm f/5.6 -- this would cost a nontrivial chunk of change and likely price Canon a soid 2-3x above the other options out there.
- Something - 400mm f/5.6 with an in-line 1.4x -- this would keep the size / cost down, but the effective 560mm f/8 would (a) violate the f/5.6 EF lens rule, and (b) have the typical drawbacks of teleconverters -- slower AF, limited AF points usable, altogether not working with AF through the viewfinder on some older bodies.
- Something - 400mm f/4 with an in-line 1.4x -- Effectively, a 'budget' flavor of a $12k lens at the same max aperture. Though it would satisfy the f/5.6 rule, I just can't see Canon undermining a big white with a same-speed lesser option. And it wouldn't be that inexpensive anyway -- compare Canon's 400 f/4 vs. 400 f/5.6 today.
My money's on the first option presently. Nikon hit the budget / long sweet spot with that one and it satisfies the f/5.6 rule.
- A
Upvote
0