Endpoints not remembered correctly when extension tubes in use

[psizz]

Hi,

I am using a Nikon D800E with Nikon 105mm macro lens. All works great until I add Kenko extension tubes into the mix. I can still control the autofocus from Helicon Remote. But if I set the near and far endpoints (in that order), and then try to go back to the near endpoint, it doesn't go nearly far enough (same if I do things in opposite order and try to go back to the far endpoint). It does the same when shooting the stack, so I don't get a usable stack.

I saw someone in the forum using Canon had sort of the opposite problem (overshooting the endpoints) and suppose this could be related. Any ideas?

Thanks

[Catherine]

Overshooting the end point is most likely not a bug at all (I won't go into details here since your question is not about that).

As for the problem you've described: some lenses are inherently prone to it due to mechanical imperfections, but your case is certainly not that since the lens works fine on its own. My best guess is that the extension ring is too smart and it recalculates the focus step sizes that the body sends to the lens. Or maybe it cuts power to the lens before the lens finishes the movement so it always falls short. I don't have any useful ideas, sorry.

[Gmbexpert2020]

The thicker the extension tube used on a lens, the higher the lens ... It's for this reason that you should generally not leave an extension tube in place all the time. ... at the absolute closest focus point, so they correct distortions for that point. ... What you should remember

[psizz]

Thanks for the responses.

I would be interested to know if anyone in the community is using this combination successfully. And, if not, is anyone using the camera/lens combo with a different set of tubes?

And finally, has Helicon staff tested this combination?

thanks
Peter