/dist/images/branding/favicon

Not loving those RADIANS.

Discussion in 'Cinestar 8' started by Chris Babiana, Apr 17, 2013.

  1. Chris Babiana

    Chris Babiana Member

    Joined:
    Nov 8, 2012
    Messages:
    183
    Likes Received:
    15
    I've read every thread in this forum regarding radians, reviewed and tried many settings on the Google spread sheet, tried settings others have posted, added o-rings, removed o-rings, mixed o-rings, stiffened the mounting plate, balanced motors, balanced the gimbal, rebalanced the entire machine more times that I have patients for, CG of camera, adjusted PID Goyo, ACC/Comp setting and spent oodles and oodles of time in the radian software experimenting with my own settings then test flying, changing settings again then flying, changing setting again then flying...it's like groundhog day with ZERO success. I've watched some rather smooth video here (with the occasional classic roll twitch) and I'm wondering what I need to do to achieve those results.

    Should I ditch the 5D for video and purchase a camera from the Sony HDR-CX lineup and let the lens correct the twitches? Will it actually correct the twitches and not be visible after stab? I'd rather get it right with what I have. Any insight would be helpful.

    Short video:

    CS8 - 2-Axis - 5DMKII - Radian Software 1.1

    Photos of current settings. I've tried gain settings between 70 and 220 on both tilt and roll. Anything beyond 120 and radinas resonate immediately.
     

    Attached Files:

    • 1.JPG
      1.JPG
      File size:
      454 KB
      Views:
      25
    • 2.JPG
      2.JPG
      File size:
      626.5 KB
      Views:
      21
    • 3.JPG
      3.JPG
      File size:
      391.1 KB
      Views:
      21
  2. Steve Maller

    Steve Maller UAV Grief Counselor

    Joined:
    Oct 30, 2012
    Messages:
    3,981
    Likes Received:
    807
    Chris, what lens are you using on the Canon?

    I go back and forth with the 5D Mark III and Sony CX760V, and while the Sony’s stabilizer cures many ills, its image quality isn't anywhere near as good as the Canon. In looking at your video, it's definitely not stable, but that could be a lot of different factors. One thing I did was to fly my copter a lot with just a GoPro bolted to the frame, and tried to get all the vibrations, etc. worked out before I put on the gimbal. I also used a GoPro pointed at the gimbal to watch it after flights, which is how I figured out one of my servo cables was snagging and causing burps.

    IMHO the MōVI is going to cure a lot of these issues, but for $15,000, it's a pretty big leap.
     
  3. Chris Babiana

    Chris Babiana Member

    Joined:
    Nov 8, 2012
    Messages:
    183
    Likes Received:
    15
    Hi Steve.
    I have the 24-105 on the Canon...heavy glass. For o-rings I have 3 red and 3 blue to compensate for the weight of the camera and the expected warm summer temperatures just around the corner. I had the same results with all red o-rings. From your prior observations, what was the cause of, or where did you notice most of your vibrations coming from? I have a few GoPros I can mount to test with. Did you get any jello with the GoPros?
     
  4. Steve Maller

    Steve Maller UAV Grief Counselor

    Joined:
    Oct 30, 2012
    Messages:
    3,981
    Likes Received:
    807
    Whoa...that's heavy glass. Never flown with anything that heavy. Balance is going to be super critical with that camera/lens combo. And any movement of the camera is going to move the copter, and you can end up with the kind of jittery picture you have. I'd also try flying with the Radians off and see what happens.
     
  5. Dave King

    Dave King Well-Known Member

    Joined:
    Dec 24, 2012
    Messages:
    2,712
    Likes Received:
    311
    Chris

    I tried a few different cameras and I have not seen anything as close at the Sony 760 for stabilization. It's dramatically different from what I have seen. I agree with Steve that the quality of the 760 isn't quite as good as the DSLR's but unless your doing really high end stuff I don't think it matters that much. IF you are doing higher end stuff you might as well at least get one of the new black magics. Just my opinion. I think that there's trade off's to going with higher end cameras such as red, black magic, or DSLR's as far as stabilization goes. For me the 760 is good enough for what I am going to do for video and for high end photography I will use a DSLR.
     
  6. Chris Babiana

    Chris Babiana Member

    Joined:
    Nov 8, 2012
    Messages:
    183
    Likes Received:
    15
    It is heavy, I completely agree, but others are flying the RED Scarlet which weighs 5lbs without the lens.
    Would I see better results with a prime...say 20 - 24mm? What do you fly on your MKIII?
    I'll head out now without the radians on and post a followup video in a few.
     
  7. Chris Babiana

    Chris Babiana Member

    Joined:
    Nov 8, 2012
    Messages:
    183
    Likes Received:
    15
    Hi Dave,
    I was beginning to conclude along those same lines...the trade off in stab. I'm considering purchasing the Sony you fly, but before spending more cash, I was hoping to get some better results from my DSLR.
     
  8. Howard Dapp

    Howard Dapp Active Member

    Joined:
    Aug 18, 2012
    Messages:
    977
    Likes Received:
    111
    The problem is not the 'heavy' 24-105 lens or the 5D...the problem boils down to the stabilization components. Others have proven this by sharing videos with stab on/off, comparison videos show that there is little to no jitter with stab off.
     
    Steve Maller likes this.
  9. Steve Maller

    Steve Maller UAV Grief Counselor

    Joined:
    Oct 30, 2012
    Messages:
    3,981
    Likes Received:
    807
    I use the new Canon 24/2.8 IS. It's really light, image quality is quite nice, and it has IS (which helps a little bit, too).

    Here are some weights:
    EF 24mm f/2.8 IS USM: 280g
    EF 24-105mm f/4L IS USM: 670g
    EF 17-40mm f/4L USM: 500g (the heaviest lens I tried flying with...and gave up)
     
    MIke Magee likes this.
  10. Chris Babiana

    Chris Babiana Member

    Joined:
    Nov 8, 2012
    Messages:
    183
    Likes Received:
    15
    To Howard's point, a video with radians off...no jitters (well...besides my flying skills in 20mph gusts just under tree branches). There's not a lot of overhead room in my back yard.
    How was the raw footage with the potentiometers, before the radians took center stage?


    Steve...so my EF 70-200 f/2.8 L is out of the question then? :D
     
  11. Tim Joy

    Tim Joy Active Member

    Joined:
    Aug 2, 2012
    Messages:
    405
    Likes Received:
    72
    Just go lower on the gains and you should be fine. Start at 30 or so and work up to twitching level. My theory is the heavier an axis is, the more susceptible to gear train slop/ flex it is. No matter what, a servo is going to have some play.
    Another trick is to use felt or some other material underneath the servo pulley that will give it some friction with the servo case.
     
  12. Adam Paugh

    Adam Paugh Distributor

    Joined:
    Jun 29, 2012
    Messages:
    323
    Likes Received:
    78
    Very good results with the 24mm IS here too. Long lens make balancing difficult, as much of the camera mass is cantilevered over the front of the tilt tube. Prime lenses and compact payloads usually yield the best results.

    Greetings,
    Adam
     
  13. Brad Meier

    Brad Meier Active Member
    Staff Member

    Joined:
    Aug 14, 2012
    Messages:
    749
    Likes Received:
    66
    Chris, I feel your pain.. And anger. I've been there.

    I fly a 5D3 with 16-35. It's very close to your weight. Your results are not terrible. I've come to the conclusion that the Radians work very well and are high quality. The other components of the system are where you may be having issues. First step, no red rings. I fly with all black even in winter. With red rings the Radians are having to react to compensate for the "loose" red rings and the copter flight and the servo belt being loose and it's working with the servo which inherently has a dead area (hence direct drive technology). So after the tighter rings, tighten the belts - I suspect you have that down just based on what I see. Also the double star mount plate helps to stiffen things up. The Freefly birds at NAB have this mod for the heavier cameras. Sorry for the stream of random thought. I've been writing this in between breaks at work
     
  14. Brad McGiveron

    Brad McGiveron Active Member

    Joined:
    Jul 7, 2012
    Messages:
    396
    Likes Received:
    65
    Chris, the gimbals carrying Reds/heavy cameras and having good success are heavily modified. As Brad said, you need to stiffen the thing to near hard mounted for best results. As Tim said there are tweaks like the felt on the servo pulley.
    I have never had issues with the Radians themselves as they are pretty much the best out there( currently ), but the gimbal is not up to the challenge out of the box. You gotta do these...

    -way stiffer vibration plate. Double etc etc
    -grommets around standoffs on the isolators
    -black rings
    -more

    or go with lighter camera in which case most of these help anyways.

    Also the camera balance should be just fractionally bottom heavy so it doesn't get accidentally top heavy due to vertical(and horizontal) forces and start searching, which is the twitching center hunt it does if there is any slop in the chain. Which there is.
     
  15. Brad Meier

    Brad Meier Active Member
    Staff Member

    Joined:
    Aug 14, 2012
    Messages:
    749
    Likes Received:
    66
    Wow, sorry about that response. McGiv said it better. Make it stiff, the Radians like it.
     
  16. Chris Babiana

    Chris Babiana Member

    Joined:
    Nov 8, 2012
    Messages:
    183
    Likes Received:
    15
    Thanks everyone, I'll give these suggestions a shot in the am...the stiffer the better...check!
    As for now, a bit of Jameson Irish on the rocks to cool the smoldering brain cells!
     
    MIke Magee likes this.
  17. Shaun Stanton

    Shaun Stanton Active Member

    Joined:
    Oct 27, 2012
    Messages:
    748
    Likes Received:
    127

    I am in the same boat. I flew this past week with a SONY FS100 with 18-200mm glass. Heavy as hell for the standard lift CS. Red dampers bobbled all over the place, but the Sony sensor was spot on. The Sony stabilization coupled with warp stabilization fixed all most all of our ills. I had to fly with the 200mm extension arms on my setup. Most of the time when I fly the MKII I have to move the camera pretty far forward. There was no way in hell the 5D MKII would have created the same footage as the FS100. I find that I can get away with all reds if I am flying a light camera. I use a small Vixia for training purposes and that thing Jello's all over the place. The better sensors seem to handle it. My big beef with this gimbal is the plastic "Lego" parts that were used for the clamps. I am now switching to the metal ones in hopes of stiffening the tilt arm more. You can crank those bolts as tight as you want on the tilt arm with the plastic clamp and the arms still work there way down.
     
  18. Brad Meier

    Brad Meier Active Member
    Staff Member

    Joined:
    Aug 14, 2012
    Messages:
    749
    Likes Received:
    66
    Sometimes I go back and look at footage from 2 years ago that I thought was pretty good at the time. From 2 axis off MK boards to 3 axis MK and now Radians, its quite an improvement. It's hard to watch that early stuff ...
     
  19. Bryan Harvey

    Bryan Harvey Member

    Joined:
    Nov 3, 2012
    Messages:
    227
    Likes Received:
    18
    I could have written this exact paragraph myself. I'm also pretty discouraged.

    I have doubled the gimbal plate, but I got blue o-rings for my 5d with 20mm Nikon prime lens (I guess a mistake).
    Have not tried the felt yet.

    Not many Wookongers on this board, but does anyone have any Wookong M flight controller gain setting recommendations with a 5d? Have not messed much with those.

    And yes the Sony CX760 will change your life, almost like cheating, but picture quality is nothing like some other options out there.
     
  20. Brad McGiveron

    Brad McGiveron Active Member

    Joined:
    Jul 7, 2012
    Messages:
    396
    Likes Received:
    65
    Can you post a flight with and without radians on?
     

Share This Page