Adapter thread. The new Lords of the Rings.

[mxbianco]

Earlier Kenko products (for F mount) were rather shoddy. I think I'll order the Meike instead. *Done*

I bought the Meike 11+18 tubes in december, they work fine with Z lenses, and they work even connected to an FTZ, they pass on all the signals to all lenses I tried (native and chipped). Naturally you have to keep all your contacts spotlessly clean!

Ciao from Massimo

[John Geerts]

I bought the Meike 11+18 tubes in december, they work fine with Z lenses, and they work even connected to an FTZ, they pass on all the signals to all lenses I tried (native and chipped). Naturally you have to keep all your contacts spotlessly clean!

That is great news.  Thanks for the update, Massimo.

[simsurace]

I bought the Meike 11+18 tubes in december, they work fine with Z lenses, and they work even connected to an FTZ, they pass on all the signals to all lenses I tried (native and chipped). Naturally you have to keep all your contacts spotlessly clean!

Ciao from Massimo

Thanks for posting about your experiences.

[Michael Erlewine]

I was hoping for an extension like the Nikon 8mm AI Extension Tube PK-11A, which I have used a lot in the past. with some success.

[simsurace]

I think 8mm would be pushing the limits of what is possible while ensuring adequate material thickness. I have not seen any that are thinner than 10mm. It is tempting to fire up a CAD program and try to design one. But then you need someone to manufacture it. Maybe someone like Amedeo Muscelli (his adapters have been mentioned in this thread) could help.

[Michael Erlewine]

I think 8mm would be pushing the limits of what is possible while ensuring adequate material thickness. I have not seen any that are thinner than 10mm. It is tempting to fire up a CAD program and try to design one. But then you need someone to manufacture it. Maybe someone like Amedeo Muscelli (his adapters have been mentioned in this thread) could help.

Well, 8mm works well on the Nikon DSLRs via the PK-11A that I have used for Please explain why this would not work on the Z flange.

[Roland Vink]

The K1 extension ring is only 5.8mm thick, but has no pass-through mechanical or electronic contacts. This is probably about the thinnest extension tube that is physically possible. I imagine an equivalent Z-mount extension tube would be possible, and it should be possible to include pass-through electronic  contacts.

[Birna Rørslett]

Well, 8mm works well on the Nikon DSLRs via the PK-11A that I have used for Please explain why this would not work on the Z flange.

The contacts are positioned differently between F and Z mounts, and so are the bayonet details and the release lever. I quickly measured the original parts of male+female Z mounts and the contacts that I got from Nikon, and anything narrower than about 10mm would be next to impossible. If one removed the contact pass-through, perhaps 1mm thinner is feasible if the release can be remodelled to fit. Thus, the dream of a Z-version of the K1 has to go.

If commercial alternatives are around 11mm, stick to them.

[simsurace]

Please explain why this would not work on the Z flange.

Well, I had a quick look at the mount and took a few measurements. The issue is having adequate material thickness where the narrow part of the male mount transitions into the female one. But to really find the limits I would need to make a drawing/3d model.

[simsurace]

It would be easier to manufacture a replacement mount that is longer by the amount you need and then to attach it to the lens. A cheaper alternative would be to put shims between the mounting surface of the bayonet plate and the bayonet plate itself, possibly combined with using longer screws. This is much less flexible but you could achieve arbitrarily small extension.

[Birna Rørslett]

Adding a thin ring to the rear of the lens, then bolt the mount onto that ring is of course feasible. I would hardly call that an extension ring though, rather a modified lens. There might be additional issues with the cabling to the contacts.

Shimming the mount must be done on the lens' side. Due to the position of the mating contact surface, only the tiniest shim up to 0.1mm can be used in the camera's mount, lest all electronic communication stops working. For the lens bayonet, up to 0.6mm might be added, but anything more again breaks the communication to the camera.

Don't mention this idea to the Nikon engineers designing the optics of the Z system, as they would cringe by the thought of their brainchild optics being abused. Extension is *never* without negative side effects and the only way to mitigate this issue is having the extension incorporated in the original optical design.

[Birna Rørslett]

Well, I had a quick look at the mount and took a few measurements. The issue is having adequate material thickness where the narrow part of the male mount transitions into the female one. But to really find the limits I would need to make a drawing/3d model.

Simone, just putting a female mount on top of a male Z mount makes more than 8mm of thickness without any consideration of how to work a release lever (I do have the parts).

[simsurace]

Simone, just putting a female mount on top of a male Z mount makes more than 8mm of thickness without any consideration of how to work a release lever (I do have the parts).

I'm assuming you have the female mount that normally sits in the camera and a male one that normally sits on the lens, and you are stacking them on top of each other. If I'm not mistaken though, a custom ring could be made such that the male 'lands' of the lens, i.e. the parts of the male mount that stick out, would sit just on top of the 'lands' of the female mount, reducing the extension to the sum of the depths of male and female lands, which seems to total approx. 3.5mm. This would result in extensions of 3.5mm and upward. Let's say 4mm to play it 'safe'. The big question is whether the remaining space is sufficient for the material thickness and structural stability of the ring.

[simsurace]

Shimming the mount must be done on the lens' side. Due to the position of the mating contact surface, only the tiniest shim up to 0.1mm can be used in the camera's mount, lest all electronic communication stops working. For the lens bayonet, up to 0.6mm might be added, but anything more again breaks the communication to the camera.

Are you talking about putting shims between the male lens mount and the next surface (I don't know the right name) in the lens? Are the contacts not connected to the electronics via cable? Then what I suggested above may not work at all.

EDIT: I guess not, since you covered that in your first sentence. But shimming the mount on the 'exterior', besides possibly messing up electronic contact, would increase the distance between the spring-loaded parts of the mount and the front surface, requiring more force and potential damage to the mount. This distance seems to have a fairly large tolerance, so maybe electronic contact would cease before mounting/unmounting becomes a problem.

[Birna Rørslett]

Your latter assumption is correct.

Don't forget to include space for the lens release lever to move and work in your calculations. There is no way one could make an independent extension as short as 4mm for the Z. Consider the K1 for F is 5.8mm and the Z mount will need more.

If one allows replacing the original mount on the lens side, much narrower values could be reached, but then we have a bespoke modification of the lens, not an extension ring.

A final point about the contacts: if the shimming is on the lens' side, the contact block moves with the mount surface itself. Thus this approach eschews the problem of lost communication to the camera. One does need to redress the internal cabling and possibly make a replacement, though.