470 to 670 nm is about what to expect from an ordinary camera lens. Problem will be diameter though, "aiming to scale to 1 cm".
https://www.lenstip.com/179.9-Lens_..._ZS_ZE_Ghosting__flares_and_transmission.html
Haven't seen any side by side with Lumix G9 and D5 but it seems that contrast detect is closing in on competition.
And 20 fps with continuos AF is faster than any DSLR.
"The Panasonic G9 represents the most capable Contrast Detect AF camera ever released. Proof of this is the fact that is
aced all of our autofocus tests"
https://www.dpreview.com/reviews/panasonic-lumix-dc-g9/6
That's a nice transmission graph of the Zeiss lens. It all depends on what the transmission levels are outside of the range quoted. Ramping up from 80%+ on both sides evenly is not really going to affect the whiteness of the image to human eyes. I'm puzzled as to what is meant by an "efficiency" of 20% at 500nm in the meta lens paper though .... if that's transmission % then there's a long long way to go regardless of lens diameters achieved.
As far as the contrast detect AF of the Panasonic G9 goes though, being the best 'Contrast Detect' AF system doesn't put it in the same category as the best AF system (Nikon D5), and it's not quite up to the levels you have said.
From the same DP review .....
(some) Cons:
* Depth from Defocus flutter is distracting when shooting action
* EVF resolution drops when shutter is pressed
* 20 fps mode using electronic shutter can result in rolling shutter effect
(from) Conclusion:
" ... while the 20 fps burst mode is limited to about 50 shots, the 9 fps burst speed (using the mechanical shutter) can go for hundreds of frames."
"Even more impressive is the fact the G9 can track a subject at its top burst speed with a very good hit rate. All this is good news, but its worth pointing out that the way in which its Contrast Detect AF system works is by very rapidly 'wobbling' the focus element back and forth to constantly ensure peak sharpness. In use, this 'wobble' or 'flutter' can be pretty distracting in the EVF, especially if you're trying to follow action. This was a problem I consistently ran into while shooting basketball."
"Panasonic made improvements to Dual I.S. 2 in the G9, which works by combining the camera's 5-axis sensor stabilization with lens-based stabilization (on compatible lenses). Those improvements have paid off, because the G9 offers the best stabilization of any camera we've tested. We were able to measure 5 2/3 stops of added hand-hold-ability at 200mm, besting the previous champ EM-1 II at the same focal length by 2/3rds a stop."
The Final Word:
"Of course, for a very similar price to the EM-1 II and G9, one can snag the sports-shooting-beast Nikon D500. To that point, if you are not already invested in a system and stills are your primary focus, I'd have to recommend the D500 over either m43 options. Its AF performance is in a league of its own,"
It is interesting that the G9 only received a 'Silver' award even though it more or less matches the Olympus OM-D EM-1 II, primarily because it is a year on from that camera's 'Gold' award. Salient message for Nikon here - merely matching the hatch does not equal market leadership.
From this, the rest of the competition, and Nikon's own statements of intent re- leading IQ, EVF performance, and it's existing reputation for the best AF, I think we can deduce several important factors around Nikon's Mirrorless offering:-
(i) Nikon is likely to offer high end model$ despite the compact body size
(ii) No mention has been made of IBIS but I think it would be a must, and would have to at least equal the best if not move the game on
(iii) The EVF will have to be the best ever seen. It will have to be without compromise as seen on the competition.
(iv) AF performance will have to trump the competition.
Wishes:
** I would love to see an exposure histogram visible in the part of the EVF during normal focusing along with all the other usual information - this would make exposure compensation so much easier. Does anyone know of another camera that does this?
** I would love to see not only 'eye-start' AF as on my old film Minolta SLR, but continuous 'eye-directed AF' as well
** An add-on horizontal battery grip in hand filling DSLR style
Chosun :gh: