Helicon Soft Forum

Hello!
two years ago I've reported a problem here on this board with the same lens on a different camera (D90). I was unable to set the "A" and "B" in fine steps in Helicon Remote and Nikon Camera Control. The lens was faulty and it was fixed by Tamron support. After that, everything worked fine.
Since then I didn't used that lens with Helicon Focus - until today where I am facing a different AF problem. After setting the "A" and "B" points and jumping back or forward to either of these (by arrow keys) there not turning back into the correct position and therefore out of the defined focus points.
When I start HR taking pictures and have the camera set to AF-S the focus doesn't change and I get a bunch with identicaly focused pictures. Setting the camera to dynamic AF (as suggested by another user in these forum) the focus changed obviously while taking pictures but the result is far outside of the defined "A" and "B" points.
Other lenses are working perfect. The question is if this is another Tamron lens fault or could it be a a Helicon Focus software related issue with this particular lens?
I want to rule out the latter before contacting Tamron support again. Thanks!

Could be a software issue. Unfortunately, it's hard to tell. Set AF mode to AF-S, disable all kinds of continuous servo AF etc. Set A and B points at some fair distance between each other and move between A and B many times (using the big arrows that move focus right to A or B point, not the regular focus step buttons). What kind of focus positioning error do you see? Is it random error, or does it always move less distance than required?

Hi Stas
first of all, I'd like to thank you for your quick reply!
I've done some testing as you suggested and put the camera into AF-S.
After setting the A and B point and switching once via the A/B Arrows the focus is sometimes correct...After switching again (after 2-4 times) the A focus point moved towards the camera and gets totally out of focus. B point stays sometimes correct but is moving towards camera too after another couple of switching between A and B.
There is some degree of shifting of both points towards the camera to some degree (max. approx. 3-4 clicks of the ">>" key).
The taken pictures doesn't show any sign of a stepping focus - there completely out of focus.
Weird...!

Hi Stas
was your last post here the end of this thread/matter?

No, we're just having hard time coming up with any reasonable explanation for this phenomenon.

Hi Stas and F.K.

I've come across this thread after having exactly the same problem as you have described - using a Nikon D810 and a Tamron 90mm Macro lens (non VC version). The A and B points seem to drift away from what has been set!

I don't see it as mechanical slack, the lens has an internal motor and is not screw driven by the camera's motor.

Have either of you come up with a solution? Thanks in advance!

Adrian

It doesn't matter where the motor is located. And we can't solve the design flaw of the lens's mechanism.