fixed speed panning, locking tilt without drift

Discussion in 'MōVI Pro' started by Francis Lane, Aug 7, 2019.

  1. Francis Lane

    Francis Lane New Member

    Joined:
    Aug 6, 2019
    Messages:
    2
    Likes Received:
    0
    Hey!

    I'm trying to use the movi pro like a motion control head. I want to lock the tilt axis and pan at a fixed speed using the movi controller. This seems an easy setup but the only problem I encounter a tiny drift. Any ideas how to prevent this?

    Increasing the tilt stiffness helps somewhat

    Reducing & increasing the range of tilt speed doesn't help

    Tilft smoothness hitting the max & minimum doesn't help

    Tilt window hitting the max & minimum doesn't help

    Tilt expo hitting the max & minimum doesn't help

    Cheers
     
  2. Graham Futerfas

    Graham Futerfas Well-Known Member

    Joined:
    Oct 19, 2015
    Messages:
    1,229
    Likes Received:
    239
    The Movi Pro's not really frame-accurate as a motion control head. It's a stabilizer, not a repeatable head, and motion control is really outside of the Movi Pro's purview.

    Regarding Tilt Drift: Do you mean it's drifting or jumping? I can correct for a little drift by increasing the Pan and Tilt Window (under the Dual-Op settings) to 2, and while I don't usually have Tilt drift, I assign Pan Drift correction to one of the User knobs. This will fine-tune it out.

    If it's Jumping -- tilting up and down slightly on occasion -- this can be reduced by reducing your Hold Strengths, which is under Tuning. I do see this problem a lot when I switch the Movi from handheld to remote with the Movi Controller. The Hold Strengths are now defaulted kind of high, I think, and this can cause the Movi to jump a bit, especially noticeable on static lock-off shots.
     
  3. Francis Lane

    Francis Lane New Member

    Joined:
    Aug 6, 2019
    Messages:
    2
    Likes Received:
    0
    Thanks for helping me!

    Agreed the movi will never be frame-accurate like moco rig, I've been forced into this situation by budget constraints of the job. If I could lock the tilt, and then pan at a fixed peed then that should be good enough for my uses.

    I definitely mean drift. I set the frame then come back 5 minutes later and its now ever so slightly different, or I pan left and right and then when i come back to the same spot the tilt is just slightly off. I don't mind drift in the pan axis, it's only the tilt that I really need to lock.

    I will try what you said re: Tilt Window. On the controller/movi I was using the default Tilt Window was 8. You said "increase to 2", does that mean you typically have it set to 1? Also when you said "Pan Drift correction", is that an actual function or you just a way of you describing Window adjustment?
     
  4. Graham Futerfas

    Graham Futerfas Well-Known Member

    Joined:
    Oct 19, 2015
    Messages:
    1,229
    Likes Received:
    239
    Well, I usually use my Movi Controller with a set of Alpha Wheels, so a Window of 0 can be desirable for operating with wheels -- the Movi becomes very responsive, however it will drift a bit.

    Using an Alpha Wheels SBus XR module, which bypasses the Movi Controller, there is no drifting because it's a digital interface verses Analog. Analog transmitters have some noise in them that can cause some drifting (according to my friend at 1A Tools), but the digital ones only have 1's and 0's with no noise issues.

    If you're using the Joystick, it could be that you're in-advertantly putting some tilt into the Pan movement, so a higher window should start to ignore this. Or you might be able to assign Pan to one of the Iris or Focus knobs... I'm not sure.

    You can assign things to those User knobs in the Movi Controller menu. I think it's in the Tx Config menu. There should be Pan Drift and Tilt Drift, although my Movi Controller's not set up an the moment, so I can't look for you.
     
  5. Graham Futerfas

    Graham Futerfas Well-Known Member

    Joined:
    Oct 19, 2015
    Messages:
    1,229
    Likes Received:
    239
    Ok, I had the Movi Controller set up on a shoot, and had a moment to play with it.

    I was able to take the Tilt Window way up to like 60 micro seconds, and it easily ignored any tilt input from the Joystick. I’m not seeing any drifting in the tilt axis at all, and it’s holding tilt pretty consistent when I pan back and forth with the joystick.

    You could also turn the Map Tilt Input from Joystick to one of the GPIO’s if you want to ignore it completely, but turning up the window was also easy enough and you could still adjust it if you want.
     

Share This Page