Thread: EF to RF mount flexes using PDMovie follow focus on Tokina 11-20mm

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  1. #1 EF to RF mount flexes using PDMovie follow focus on Tokina 11-20mm 
    Hey, was super excited to get my Tokina today. Hooked it up with the remote follow focus and was surprised to see the lens mount flex a lot on quick moves. I shot some handheld footage that I tried to stabilize quickly to better show the flexing. One thing you can't really see in the video is how it lifts and lowers the mount besides the slight jiggle. Any idea on how to solve this? Thanks!

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  2. #2  
    This is quite common. Firstly depending which PD Movie you have you can adjust the amount of torque so if the lens doesn't need it then reduce it. Also on the rods (not sure where you have them) but a clamp at the end of them to join them together and gain some extra stability. However as you say the mount itself is flexing and that's not good - isn't there a range of 'chin' accessories and other mounts that are more secure?

    cheers
    Paul
    -------------------
    insta: @paul.inventome
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  3. #3  
    Senior Member Alex Lubensky's Avatar
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    That's exactly why I'm telling everyone that adapters are shit. You can get a 100% robust result only with a native mount.

    Otherwise, there are mounts with support screws to hold them in place. I believe there's a thread on this topic on the forum.
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  4. #4  
    This was my first heavy duty cinema lens, I was shocked when I saw get lifted and lowered and jiggle a little side to side. I bought the lens local and I think the best approach for their 10 day return / exchange policy is to swap out the mounts to the PL mount. I looked for other EF to RF mounts with support but there are no good options. PL mounts look like they can be connected to rod support, even my Tilta stormtrooper cage came with a PL mount. The EF to RF mount had no issues using simple Canon photo lenses, but man, you put a real cinema lens on it with a follow focus and that EF/RF mount is useless.
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  5. #5  
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    See the thread on PL mounts for Komodo. ANY mount-- even the best-made PL-- will have flex, because they're just held to the Komodo's RF mount with a lightweight spring mechanism. So you'll need a support of some type. Some mount adapters offer screw threads on the bottom. Metabones makes a rod support that grabs the arca plate on the bottom of their adapters (which also have a thread for screw support).
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  6. #6  
    Quote Originally Posted by M Harvey View Post
    See the thread on PL mounts for Komodo. ANY mount-- even the best-made PL-- will have flex, because they're just held to the Komodo's RF mount with a lightweight spring mechanism. So you'll need a support of some type. Some mount adapters offer screw threads on the bottom. Metabones makes a rod support that grabs the arca plate on the bottom of their adapters (which also have a thread for screw support).
    Thanks. This became apparent right away that I needed another way to remove the stress from the mount. I will look at the Metabones option.
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  7. #7  
    Senior Member Jacek Zakowicz's Avatar
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    I think this is going to be the biggest fail of Komodo- a lack of solid, positive locking lens mount. I hope they fix it sooner than later.
    Jacek Zakowicz, Optitek-dot-org, jacek2@optitek.org
    Professional Broadcast and Digital Cinema Equipment
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  8. #8  
    Not all adapters are "sh!t". The problem here is RF is a still lens mount and EF is a still lens mount, both with relatively weak spring/tension systems designed to hold still lenses(and in the case of large heavy still lenses with still cameras, they are "holding" the still cameras). So the OP has a camera with a native, non-locking still lens mount, an adapter that is a non-locking still lens mount and a heavy-ish cine lens with force being applied to it via a focus motor. The OP needs an adapter that is able to be secured to the body, cage, rails(iris rods), etc. so that it doesn't move/flex, exert undue torque on the native camera mount when loaded. And ideally find an adapter with a locking mount on the lens side(whether its EF, PL, etc.)(like on the Optitek EF/FZ adapter if it's EF). Then they need to support/secure the lens to the rails(iris rods). I don't even trust PL for long, heavy zooms. That is a LOT of torque being dished out. I ALWAYS tie my 17-120 into a threaded lens support on the iris rods.
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  9. #9  
    Quote Originally Posted by Christopher A. Bell View Post
    Not all adapters are "sh!t". The problem here is RF is a still lens mount and EF is a still lens mount, both with relatively weak spring/tension systems designed to hold still lenses(and in the case of large heavy still lenses with still cameras, they are "holding" the still cameras). So the OP has a camera with a native, non-locking still lens mount, an adapter that is a non-locking still lens mount and a heavy-ish cine lens with force being applied to it via a focus motor. The OP needs an adapter that is able to be secured to the body, cage, rails(iris rods), etc. so that it doesn't move/flex, exert undue torque on the native camera mount when loaded. And ideally find an adapter with a locking mount on the lens side(whether its EF, PL, etc.)(like on the Optitek EF/FZ adapter if it's EF). Then they need to support/secure the lens to the rails(iris rods). I don't even trust PL for long, heavy zooms. That is a LOT of torque being dished out. I ALWAYS tie my 17-120 into a threaded lens support on the iris rods.
    ^^this

    Heavy lenses need to be supported. Running cine lenses on RF mounts?. You'd be best to strap that lens to the same rails the focus motor is on. I don't see this as a fail on the part of RED though...I'll save that one for the RF mount never working with RF glass. Bazinga.
    DSMC2 Dragon-X
    waiting on Komodo...
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  10. #10  
    Quote Originally Posted by Brian Roberts View Post
    ^^this

    Heavy lenses need to be supported. Running cine lenses on RF mounts?. You'd be best to strap that lens to the same rails the focus motor is on. I don't see this as a fail on the part of RED though...I'll save that one for the RF mount never working with RF glass. Bazinga.
    Indeed. I bought the lens at Duclos locally. They have a 10 day return / exchange in store credit. I noticed the box said Lens E on it but it fit my EF mount fine, so I am guessing they did a mount swap. Hoping they can just swap it to a PL mount instead of going through the exchange. If I knew this ahead of time I would have just got the PL Mount. This is why I like buying locally.
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