Originally posted by KX5 Im not totally happy with this update. The new 42 MP sony sensor will be expensive (compared with A7RII around 3500$). For me 36 MP is enough. There is no great difference between 36 and 42 MP. So why to spend more than D810 which is a great value for the moment?
As others have said, its unlikely that the Pentax FF will be as high priced as the Sony.
Shutter-shock is a big issue to me regarding the nominal 36mp cameras. A good friend of mine sold his D800 because of fuzzy pictures - that now appear to be due to shutter shock. Read this quote from the dpr site:
Quote: An issue we're becoming acutely more and more aware of as sensor resolutions increase is sources of mirror and shutter-induced shake. It was an issue with the first 36MP full-frame camera, the Nikon D800/E, and particularly so with the Sony a7R. All of these cameras initiate the exposure with a mechanical shutter, with DSLRs like the D800/E and 5DS/R having the additional issue of flipping a mirror out of the way first. When it comes to the mirror, camera manufacturers will typically dial in a bit of delay to allow for vibrations to die out, but even if this delay is 100% effective (our tests would suggest it isn't), a mechanical shutter often still causes some vibration, the effect of which will depend upon your focal length, as well as the duration of the exposure.
Very long or very short exposures typically won't affected, but we've found a whole chunk of shutter speeds, for example from 1/15s all the way to 1/500s, affected deleteriously by shutter shock, and optical image stabilization systems' reactions to such shock, at longer focal lengths on a Sony a7R, Nikon D810, and Canon 5DS.
Nikon's electronic front curtain on the D810, and Canon's use of an electronic first curtain in Live View, aim to mitigate these problems, but are cumbersome. Canon requires you to shoot in live view mode, and in the D810 you have to engage two shutter button presses with a delay in order to take a shot.
What likely made matters particularly worse for the Sony a7R was that the mechanical shutter had to be closed and opened to initiate an exposure, since the sensor is always exposed to light in a mirrorless camera. That's a lot of movement, with the shutter landing with a resounding thud! (literally sounding like it hits the bottom of the body frame) before opening again to initiate the exposure. At least with DSLRs, once the mirror is out of the way, the shutter only has to open (its 'default' position is closed). This shutter actuation was enough to cause significant motion blur in long telephoto shots, and even enough to cause a parasitic interaction with lenses' optical image stabilization systems to yield results such as the one below in our studio scene:
The D810 solution may or may not be a good one. I would expect Pentax to be all over this issue because of the delay in their production of an equivalent camera. - thats a good thing.
In addition, the 42mp sensor is going to be BSI sensor which should improve noise levels at high iso. If none of this is important to you, then buy whatever suits your fancy.