Not really a Nikkor. the Kerlee 35/1.2

[Akira]

I have the impression that such "coupling-less" lenses have been encouraged by the increasing popularity of live views and videos where no coupling is needed practically.

[richardHaw]

it is just cost-cutting. it may also be the direction of Nikon's aperture ring rotation
this makes it a preset aperture lens. OK for my Nikon RF but not OK for SLR unless you LV

[Bjørn Rørslett]

it is just cost-cutting. it may also be the direction of Nikon's aperture ring rotation
this makes it a preset aperture lens. OK for my Nikon RF but not OK for SLR unless you LV

Nah. 'Preset' means there is a second ring, usually without click-stops, used for closing down the aperture.  You first moved the click-stopped real aperture ring to the intended setting, twisted the preset ring to its Wide Open position, focused and composed the picture, then twisted the preset ring in the opposite direction until it stopped at the setting of the click-stopped first ring. Common on old lenses from '50s and '60s, very rarely seen these days. The old long lenses for the Nikkor S mount (18 cm, 25 cm, 35 cm at least) used to have this.

The Kerlee has just a single aperture ring so is not preset. It will stop down directly when the aperture ring is rotated.

[Asle F]

My Canon-using friends have tried to tell me, for years, that the beauty of Canon cameras are that they also can use Nikon lenses with adapter. They are truly believing it is a nice feature. And that means without any aperture linkage.

Other cheap lenses, like Samyang, is also without any aperture linkage in Canon mount. And Canon users buy them and believe it is the way to use manual focus lenses. It is understandable that they dont understand why we Nikon manual focus users are so happy with ours gears. I don't know if Samyang in Canon mount is preset.

I have a PC 35mm/2.8 and a bellows 105mm/4 that both have preset aperture, but those lenses are for special use, so it is ok. I really don't want any general use lens without aperture linkage, that is just to cumbersome.

[Roland Vink]

Using a lens with no aperture linkage - stop down metering - has certain advantages:
- You get permanent DoF preview so you always see exactly what the sensor will capture (within the limitations of the viewfinder).
- It avoids problems with focus shift because any shift occurs before you focus.
- Metering can be more accurate because there is no discrepancy between the calculated aperture setting and the actual aperture.

However it does not work so well when smaller apertures are used:
- The viewfinder becomes very dark.
- More difficult to assess critical focus due to the larger DoF.
- Less light for metering so metering starts to get less accurate.

[Airy]

Back to film times - the Canon T90 had a stopped-down mode, so the photographer had a choice. In that particular case, the photographer nearly never chose it (except at times for macro, IIRC).

[David H. Hartman]

'Preset' means there is a second ring, usually without click-stops, used for closing down the aperture.

This is what preset has always meant to me. The one preset lens I owned was really easy to flip the stop down ring to open and close the aperture. For me the preset ring was the one with f/stops engraved. The lens was a 400/6.3 and I problem never stopped down below f/11 and characteristically f/8.0 for a little better image quality. I'd "preset" f/8.0 and flip the aperture open, focus and flip the aperture closed to the preset value. Anyway that's how I though of preset.

Dave