Slow zooms

[Disappointed_Horse]

It seems as though in transitioning to their new mirrorless systems, Nikon has moved the slow end of their variable aperture zooms from f/5.6 to f/6.3. It strikes me as kind of strange that they are doing this across the board on their variable-aperture zooms when it seems like f/5.6 had been the standard for about 25 years. I believe Canon is making a similar move.

I know it's only a third of a stop difference so probably not that huge a deal, but I'm a bit OCD and it bugs me when a lens' maximum aperture is not at a whole stop. (Weird and irrational, I know.) I'm curious why two of the largest camera makers are doing this at the same time. Is it because the cameras can now correct for diffraction?

 

[jsrockit]

Could it have to do with size?

 

[KoNickon]

Size, and I suppose also because their AF systems can handle the slower lenses.

 

[Disappointed_Horse]

I'm sure it's partly to do with size; obviously, an f/6.3 lens can be made smaller than an f/5.6 lens. However, I thought the whole point of the cavernous diameter of the Z-mount was to make it easier to make large aperture lenses? Taking that into consideration, the design choice to downgrade the zoom lenses from f/5.6 to f/6.3 seems strange to me. The 24–200 and 50–250 are not exactly small lenses anyway. The 16–50 and 24–50 certainly are small, but how much bigger would they have needed to be to keep the max aperture to f/5.6? Even if they were 10% bigger, I would have preferred that than losing even 1/3 stop on the maximum aperture. Nikon made a nice small 28–50 F-mount zoom lens with a constant f/3.5 aperture in 1984! Obviously, that lens didn't have AF or VR, but still, it just seems Nikon could have done a little better than f/6.3 with the Z-mount lenses.

 

[jsrockit]

However, I thought the whole point of the cavernous diameter of the Z-mount was to make it easier to make large aperture lenses?

and they have... some small and slow zooms haven't changed that.