Could be a button to change the EVF display to another mode (e.g. from a display with exposure info on the bottom to a ff display?).I think that's just the dioptre adjustment.
The little button on the other side intrigues me though. I don't know Nikon cameras, anyone know what that symbol is? (it's not the focal plain marker)
I think the optical formula patents for several Nikon Z-mount lenses specified a 16mm flange distance, which puts it 2mm shorter than Sony's. And it would be really cool if Canon used the existing EF mount and designed their mirrorless lenses to be recessed into the body - that would actually make the lens's physical dimensions appear smaller when attached to the camera unlike Sony and Nikon. It would also provide a better balance of weight distribution and long-term use ergonomics.
Nokishita has updated the original link with specs, just for the Z7 so far. Highly likely correct at this stage.
Black = verbatim from that site, blue = my commentary
Nikon Z7 (45 x 9 = effectively, a mirrorless D850)
No comment on video, IBIS, max shutter speed, presence of an e-shutter, etc. so there's plenty of meat still on the bone to be revealed.
- 45.7 MP back-illuminated CMOS
- EXPEED 6 (Believe the D850 was EXPEED 5)
- The hybrid AF system covers about 90% of the imaging area (Good on Nikon, no need to say 4 gajillion AF points with mirrorless)
- Continuous: 9 frames / sec (With or without the grip? )
- 3.2" touchscreen
- Recording medium: XQD card (umm... only one?! Not sure this is saying that, but keep an eye on this)
- Size: 134 x 100.5 x 67.5 mm
- Weight: 675 g (~ 70% the weight of a D850 body)
- British pricing: body:£3399, lens kit:£3499, 24-70mm kit:£3999, 24-70mm + FTZ:£4099 (In line with UK D850 prices, I believe)