Well said, time for people to not associate mirrorless technology with smallness. Look at the historical context of mirrorless which startedYou can’t defy the laws of physics.
with Olympus and Panasonic introduction of the M43 format ( actually the mirrorless successor of 4/3 (four thirds) from Olympus.Their selling point is that it is smaller then DSLR cameras but in fact as the products progressed the camera body became just as big or bigger than DSLR like Panasonic's GH4,5 and so on.
Of course other companies like Sony,Fujifilm,Samsung, etc. have their mirrorless using APSC sensor which is the standard used in DSLRs apart from full frame ones. To be factual all point n shoot compacts are "mirrorless". Then Sony upped the game when it put a full frame sensor into the E mount meant for APSC sensor into their Nex and then renamed Alpha series.
Needless to say Canon and Nikon pooh poohed Sony's implementation of using FF sensor in the Nex's E mount saying optically will result in degraded image, mount diameter being too small for FF. Not only that they attacked M43 IBIS ( in body stabalisation of image) as inferior (EM1) to in- lens method which both Canon and Nikon uses. Now for some facts..it is well known that IBIS works well for short focal length lenses and not long telephoto lens.So in fact Olympus added in-lens stabalisation in addition to IBIS in it's 300mm F4 Pro lens which is equivalent in 35mm FF to 600mm because of 2X crop factor.
The irony is now Nikon chooses to implement IBIS in Z6/7 by using a bigger lens mount of 55mm as one of the reasons that there is not enough room for the
mechanism to have adequate movement in their respective axis'. Nikon also echoed M43 sales pitch by saying mirrorless technology makes for smaller camera (a thinner profile). Another reason is that it allow Nikon lens engineers the ease and possibility to design F1.2 and F0.95 aperture lenses principally as the fact that you need more lens elements to correct all light rays hitting the sensor. RGB colours in light have different wavelengths so do not hit the sensor at the same distance or point.
An interesting fact is medium and large format cameras for film uses simple ( less lens elements) design as their large format negates the necessity of complex
lens elements in order to correct lens abberations to achieve the image quality so the lens size is rather small compared to 35mm format.
Whether IBIS or in-lens stabalisation is superior remains to be seen as engineering is all about compromises.What you want to achieve at the cost of other
considerations.There is no perfect camera or lens. It is telling that Canon does not use IBIS in the EOS R mirrorless FF camera and they are not stupid.
It has become almost expected when a new lens is introduced by a manufacture to ask how sharp it is, nowadays lens marketing only sell sharpness and at all costs to the detriment to the art of photography. I'm not the first to comment or lament..that the result of designing for sharpness into a lens means other lens quality takes a hit like micro contrast and colour accuracy, the feel or look of the image which result in a dead or lifeless photo. Leica a well respected and legendary lens manufacturer has it's own philosophy about the art of photography, it does not design lenses that are extremely sharp because it knows that it will loose the lifelike and emotive quality that it's lens elicit from their images. Food for thought. To come back to topic, the reality is if you want fast lenses like 70-200mm F2.8 the lens has to be big,period. Also as far as compatibility of F mount lenses is concerned it does not mean all lenses will work well on Z mount
via FTZ adapter as one reviewer reveals about the way conventional DSLRs are designed with respect to image sensor from his comments:
Sorry for the long post.Finally, one point that everyone should be looking at: the “focal plane” of a DSLR is actually
a complex optical design. The thickness of the UVIR filter (and AA, if applicable), the setoff
of the UVIR filter from the actual sensor, the depth of the microlenses and Bayer filtration,
and the photo diode position and depth all play a part in collecting the photons from a lens
at the right spot. You can have a perfect adapter but get less than perfect results if the
focal plane optics have changed and your rear lens element isn’t aligning the light properly.
So one thing I’ll be looking at closely is whether Nikon is maintaining the current
optical system at the sensor or has made changes on this new system. We’ve already
had a minor change with the flip to BSI in the D850, which has made some older wide
angle lens designs perform a little worse at the corners, some a little better.