Today’s example with the Nikon 50mm f/1.2 AIS on the Leica M240 and the prior Olympus 50/1.2 example on the Sony A7R speak to a point that matters to me: it’s all about lenses. It is why lenses like the new Sigma 50/1.4 disappoint in one key way: with no aperture ring, there is no way to control the aperture without an electronic adapter, which might not exist and/or the quality and/or reliability of a suitable lens adapter might not be there for any particular camera + lens combination.
The Sigma decision to omit the aperture ring is probably founded on cost savings, how-it-has-always-been-done, and the mount-swap goal. But the Sigma 50/1.4 DG HSM A and Sigma 35/1.4 DG HSM A1 would be *so* much more attractive if they could be swapped between cameras in the field just by carrying a simple mechanical adapter. Whether for stills or video, a lens without an aperture ring is inherently more limiting.
A decades-old Nikkor or Olympus lens with its manual aperture ring can be fit to just about any mirrorless camera system with a simple mechanical adapter. The Nikon F-mount is the closest thing to a universal mount because it is easily adapted to Leica M, Canon EF, Fujifilm X, Sony E-mount, Micro Four Thirds.
Ditto for the wise choice by Zeiss to continue building aperture rings into even the newest designs for Nikon F-mount, like the fabulous Otus line. It makes an investment in any Zeiss ZF.2 lens a long-term value no matter what camera platform is used. And that will be true a decade or two decades from now.
As Richard Schleuning of Zeiss puts it:
Yes, quite true. At NAB, we were swapping lenses and adapters on all different type of cameras, including the Sony A7S and VG900, Blackmagic Pocket Cinema, Panasonic AF-100 etc.
The ability to control aperture without using a 'smart adapter' definitely has its benefits. For filmmakers, the aperture can also be 'de-clicked' to allow for continuous control - which is a popular retrofit from companies like Duclos lenses.
The long focus throw and hard stops of the Otus is also a consideration.
The beauty of the Zeiss approach is that the manual aperture ring is there when it’s needed or wanted on other systems, yet a Nikon DSLR still exercises 1/3 stop control electronically. Sadly, Nikon has chosen to degrade the versatility of its own lenses, even the high-end ones, moving to the “G” style lenses lacking an aperture ring, unwittingly reducing the value proposition; it has certainly given me pause more than once and kept me from buying: why invest in a lens stuck to one system, especially today.