p.5 #1 · Samyang/Rokinon 135mm f/2 ED UMC officially announced!
I don't think it has anything to do with PDAF. I think, at least with nikon, its because they'd have to reverse engineer the mount electronics and risk being rendered incompatible down the road. Also could risk legal issues or bad blood. With Sony, they have a relationship. M4/3 is open. Not sure about the others.
p.5 #2 · Samyang/Rokinon 135mm f/2 ED UMC officially announced!
aut0maticdan wrote:
I don't think it has anything to do with PDAF. I think, at least with nikon, its because they'd have to reverse engineer the mount electronics and risk being rendered incompatible down the road. Also could risk legal issues or bad blood. With Sony, they have a relationship. M4/3 is open. Not sure about the others.
They've said as much, though. Only recently (current-gen Canon and Nikon) have DSLR PDAF systems gotten extremely accurate and consistent.
They're making AF lenses for Sony E-mount in both crop and full-frame variants, as well as for Fuji's X-mount. With these all-electronic mounts (and Canon's EF-M being also all-electronic like EF, with the same dimensions as E-mount, and Zeiss licensing Canon AF for their DSLR lenses for focus confirm) there's really nothing stopping them from making AF lenses for future mirrorless systems, including Nikon's, especially if a full-frame mirrorless Nikon system is based on the all electronic 1-series mount (just larger).
p.5 #3 · Samyang/Rokinon 135mm f/2 ED UMC officially announced!
That's interesting. I'm suspicious of their assertions though. If they made that statement, I have to wonder if its to cover their own inadequacies. It really could be their lack of knowledge in AF systems that is the real issue and only now they are pumping them out because they have partners that can help Fuji (Touit) and Sony/Tamron(?) (Batis + other native lenses).
I am, of course, just speculating. I always thought AF wasn't their style since their background was in MF RF lenses. Their modern AF lenses all seem to be designed by or in collaboration with other companies.
Also, I've had: D70, D700, D7000, D800 and D750. I wouldn't say the later ones are noticeably more "accurate" than earlier ones. More points, faster, better tracking, all that: yes much better. Are they any more in focus when they lock focus? No.
p.5 #4 · Samyang/Rokinon 135mm f/2 ED UMC officially announced!
Here's the thing- they've mentioned the inaccuracies of DSLR PDAF systems, and they're spot on, particularly as a third-party vendor; note the lengths that Sigma has gone with their USB Dock to help users get their lenses as accurate as possible.
Mirrorless systems can use PDAF, but they're primarily CDAF setups (and fall back on CDAF when PDAF is used first, but fails). CDAF shouldn't ever be off; it'll either hit, or miss completely. Thus it can deliver the accurate and consistent results that Zeiss is looking for, and works quite well on X-mount with the Touit lenses and on E-mount with the Touit and Batis lenses.
