Disconnect SDI before swapping V-Mount on Komodo Tilta plate?

[Ivars Svarcs]

Hello,

Just to be on safe side, would like to confirm with you who has done it before.

Setup:
-Komodo
-Attached Tilta for Komodo V-Mount Plate (https://tilta.com/shop/dual-canon-bp-to-v-mount-adapter-battery-plate-for-red-komodo/)
-On Tilta Bebop V98Micro V-Mount Battery
-From Tilta 14.8V D-Tap power cable to Atomos Ninja V using AC to DC adaptor connected to SDI expansion module

The question is - If i run out of juice and want to swap Bebop V98Micro V-Mount Battery from the Tilta plate, should I first disconnect SDI, then swap the battery and then connect back SDI or can I just swap the V-Mount and turn on monitor?

If it is needed to disconnect SDI - should i disconnect SDI from monitor and can leave other end connected to camera or i disconnect SDI from Komodo input leaving it connected to Monitor?

Thanks.

 

[Roberto Franco]

I have the Komodo + Tilta V-Mount + SmallHD Cine 7 and would like to know if I'm doing this right:

When the battery is close to run out of juice this is what I do:
1. Disconnect SDI from camera
2. Power down the external monitor
3. Power down the Komodo
4. Swap battery
5. Turn ON the Komodo
6. Turn ON the external monitor
7. Plug the SDI on camera

I usually leave the SDI on monitor, not sure if this is right.

I also have RF and EF lenses and I would like to know:

Do I need to turn the whole setup OFF before to change lenses?
At the moment I do but it's not ideal in some situations.

Thanks.

 

[Vance Colvig]

Unfortunately the standard Tilta V-lock power adapter does not ground the 2 pin Limo connecrors because they are mounted on plastic and there is no bonding between those two connectors and ground. I personally modified mine so they are grounded to the negative pole as is the Komodo. Only then will the shielded connector of any accessory make first contact with a bonded negative outer ring of the Limo connector on the Tilta original power V-Lock adapter prior to the pins making contact..

I notified Tilta of the issue prior to their release of their new Advanced Power Module for Komodo, but I have not made a continuity check on all of the Limo connectors yet and have received no reply from Tilta regarding this issue.

 

[M Harvey]

Red has posted an article describing the recommended SDI connection procedure here:

https://support.red.com/hc/en-us/articles/360057166453-Preventing-Damage-to-SDI-Outputs

Note: they also say "The camera's power state does not have an impact on SDI attachment sequence."

I also have RF and EF lenses and I would like to know:

Do I need to turn the whole setup OFF before to change lenses?
At the moment I do but it's not ideal in some situations.

I'm not aware of any reason you'd need to shut down the camera to change lenses.

 

[Bill Ravens]

https://www.youtube.com/watch?v=MzuJfYqqJvo

 

[Dominik Gehring]

Some one in the facebook group told me that it can fry the sdi port if my v-mount battery dies (powering camera& accessories). Is that true? I can follow the routine as described but no way there won't be an occasion where my v-mount dies before i can make the swap.

 

[Alex Zeder]

When power fades away as the battery dies and all cables are left in place, there is little chance that it can still generate a short spike that eventually damages the SDI electronics.

 

[Stephen Pruitt]

There are seven connecting holes on a V-mount battery. Which one of these do we want to connect first to avoid blowing our SDI ports? The positive or the negative? I think I have a very simple way to fix this problem, but I want to make sure I know which one we want to make first contact.

Thanks.

Stephen

 

[Alex Zeder]

Taken from the ARRI article:

This damage to the SDI connection can occur when connecting an unshielded power cable to an accessory that is already connected to the SDI output of the camera. If the plus pin is contacted before the negative pin, the BNC cable will close the current circuit resulting in a fatale damage of the included SDI driver chip which itself is not desigend to handle such high currents. This problem can also occur when disconnecting an unshielded power cable of an accessory that is still connected to the SDI output of the camera with a BNC cable.

 

[Robert Hofmeyr]

There are seven connecting holes on a V-mount battery. Which one of these do we want to connect first to avoid blowing our SDI ports? The positive or the negative? I think I have a very simple way to fix this problem, but I want to make sure I know which one we want to make first contact.

Thanks.

Stephen

The ground loop issue does not happen when connecting or disconnecting the battery - it happens when a battery is already connected to the camera, then the monitor power is connected and the positive makes contact before the ground. So the current then flows in a loop: battery positive -> monitor -> SDI -> camera -> battery negative. I have yet to see an explanation of how connecting just one terminal of a battery can cause enough current to flow through an SDI cable to blow the port. I also don't understand how an SDI port blows when the monitor and camera are using different batteries.

 

[Stephen Pruitt]

The ground loop issue does not happen when connecting or disconnecting the battery - it happens when a battery is already connected to the camera, then the monitor power is connected and the positive makes contact before the ground. So the current then flows in a loop: battery positive -> monitor -> SDI -> camera -> battery negative. I have yet to see an explanation of how connecting just one terminal of a battery can cause enough current to flow through an SDI cable to blow the port. I also don't understand how an SDI port blows when the monitor and camera are using different batteries.

The problem I don't understand is how, if attaching the battery to the camera has nothing to do with blowing SDI ports, then if you never disconnect any of your SDI cables and their other power cables (which I don't), then you should never be able to blow an SDI port ever, right?

 

[TYLER STOOKSBURY]

I was told in a Facebook group that all I have to do is disconnect the SDI from my monitor and that's it.

 

[Robert Hofmeyr]

The problem I don't understand is how, if attaching the battery to the camera has nothing to do with blowing SDI ports, then if you never disconnect any of your SDI cables and their other power cables (which I don't), then you should never be able to blow an SDI port ever, right?

Yeah so this is what confuses me as well. If you are powering the monitor from its own battery, or from a cable from the camera battery, and you only connect and disconnect that cable when the SDI is disconnected, then as far as I see it you should be safe from the ground loop issue. I don't see any reason to disconnect the SDI cable before swapping a battery on the monitor or on the camera (unless that battery has a d-tap cable connected directly to it and you are removing the d-tap first). I would really appreciate an explanation of how a power surge large enough to blow the SDI port could happen without a ground loop.

That said, I should not be trusted with electronic advice, and even though I power my monitor with it's own battery I still use an isolator for peace of mind - my Jupio batteries disconnect randomly so there is no way I would be able to follow the recommended procedure in the field.

 

[Robert Hofmeyr]

I was told in a Facebook group that all I have to do is disconnect the SDI from my monitor and that's it.

Yes, disconnect from either the monitor or the camera and you are safe.