Nucleus Nano follow focus

I think I am uniquely qualified to answer your question!

tl;dr solution: lens support pushing against lens to take up flex

I have the same follow-focus unit, though I use it to adjust the geared ND in a Fotodiox Cine ND Throttle (lens adaptor with built-in variable ND). It will, of course, work great as a actual follow-focus unit (I really like it, especially the calibration feature, so cool). But I do use a different motor for actual follow-focus, read on.

I use Nikon lenses adapted to Sony cameras, and I shoot motion-control timelapse with them. While I use the Nano to adjust the ND, I also adjust focus (or sometimes zoom) during timelapses with a separate motor, and I have found that there is a lot of flex in the Fotodiox adaptors (and a few other adaptors I've tried). As you know, there's so much flex that the focus motor can sometimes turn several degrees before the flex maxes out and the gear on the lens finally starts turning. This, of course, means that my focus keyframes were always out of sync ("backlash"), and it was endlessly frustrating.

What I did to solve this problem was add a dual-rod clamp to my camera cage, and then add in a lens-support bracket (if you don't use a cage, this will work as well, to hold two rods). The key is: before clamping on my focus motor, I push the lens support bracket against the lens until it takes all the flex out of the lens/adaptor interface. This means the lens doesn't flex when the focus motor moves, and I can have pinpoint accuracy with my focus keyframes.

The same setup would work great with the Nano as well.

I should note that I haven't done any testing to see if the plane-of-focus is affected with this flex issue, though I've never noted any problems in that area with my footage. I usually shoot 1-top closed from wide-open (if I'm wanting to show obvious DOF changes in my sequences), and that's shallow enough that if there were plane-of-focus issues, I'd likely notice them.

Hope this helps solve your problem!

Chas

Here is my setup (Nano follow-focus unit is at the bottom out of sight, on a very short rod)

ATpix wrote:

Hi Folks

I've had a Nano follow focus for a while and haven't got much use out of it because of one issue.

I get a ridiculous amount of flex in the Nano base plate and rod. That's also exacerbated but what are turning out to be crap lens adapters.

I'm shooting with a Lumix S1 and old Nikon Ais manual focus lenses. For stills, no issue but with the Nano the whole image shifts when racking back and forth. You can actually seen the space between the lens and rod change when the Nano is working a little harder.

My 50 and 85 mm are a little stiffer than my 35 and 24mm but not unrealistically so. I'm using a V mount battery and D Tap cable to get the full torque out of the motor. No issues there either.

I'm using a Fotodiox to L Mount adapter. I'm coming to the realization that that may have to go. Any suggestions on a better more solid alternative?

But I think I'm going to have to go with a more solid/pro level base plate and rods setup as well. I even tried removing the rubber pads on the Nano plate. There is still flex between it and the camera body. I'm praying this isn't more to do with the base of the camera. Any suggestions on plates and rods would be great to.

Other thoughts?

Thank you.

P.S. Is there a better Forum category for this?