Thread: The SDI issues

Reply to Thread
Page 6 of 17 FirstFirst ... 234567891016 ... LastLast
Results 51 to 60 of 166
  1. #51  
    This is how it works as I understand.

    Power cables that have deep seated pins and a good shielding collar will likely do no damage. As the important thing is that there is ground / - connection before the + is added. Same rules apply as when you bumper cable start a car. Ground / minus first then add power.

    Dtap connectors does not have any kind of shielding and they got the two connector pins touching about the same time. So is a chance the + pol is connecting before the - pol and then power can run trough the device into the camera video output on its way to ground / other battery minus pol or what ever source is on or trough equipment towards real ground.


    If you look at the komodo power port it's really deep seated, it's really no chance in hel that the + pol would reach in and touch before the shield is connected. Thats how a good connector should look... now in the other hand of the power cable that red sells there is a Dtap... Which as I understand is not so good. But if you first connect that Dtap to a battery and then stick the other cable into the camera I then think that would be rather safe swapping power source on the Dtap... and keep the lemo connected to the camera, not so safe...


    But now who in their right mind could worry about these things while shooting, all the shoots I go to is like war, no time rain dancing when swapping to a new brick. So yes better connectors would be a good start I guess.
    Björn Benckert
    Creative Lead & Founder Syndicate Entertainment AB
    +46855524900 www.syndicate.se/axis
    VFX / Flame / Motion capture / Monstro
    Reply With Quote  
     

  2. #52  
    Senior Member
    Join Date
    Jan 2008
    Location
    Los Angeles
    Posts
    566
    Quote Originally Posted by Christoffer Glans View Post
    Yes, but there seems to be an increasing rate of failures compared to previous cameras and others like Arri, Sony etc. So the SDI connection on Komodo seems to be very sensitive to failure and when people follow the instructions and use 12G cables and such it should not happen this much.
    For 12G to work, I believe there's less "protection" in the electronics. If you use a heavy handed protection circuit then the 12G part stops working.

    This has been happening on lots of cameras, Arri, Blackmagic.

    The biggest issue is bad (unregulated) power, bad (lower cost) accessories, and bad powering practice combined with more sensitive now unprotected connections.

    JB
    John Brawley ACS
    Cinematographer
    Los Angeles
    www.johnbrawley.com
    Reply With Quote  
     

  3. #53  
    Senior Member Jacek Zakowicz's Avatar
    Join Date
    Jun 2008
    Posts
    3,476
    Quote Originally Posted by John Brawley View Post
    The biggest issue is bad (unregulated) power, bad (lower cost) accessories, and bad powering practice combined with more sensitive now unprotected connections.

    JB
    Unfortunately this is the reality check on film sets. Camera manufacturers know that for the most part...
    Jacek Zakowicz, Optitek-dot-org, jacek2@optitek.org
    Professional Broadcast and Digital Cinema Equipment
    Reply With Quote  
     

  4. #54  
    Senior Member Robert Hofmeyr's Avatar
    Join Date
    Sep 2009
    Location
    South Africa
    Posts
    841
    Quote Originally Posted by John Brawley View Post
    For 12G to work, I believe there's less "protection" in the electronics. If you use a heavy handed protection circuit then the 12G part stops working.

    This has been happening on lots of cameras, Arri, Blackmagic.

    The biggest issue is bad (unregulated) power, bad (lower cost) accessories, and bad powering practice combined with more sensitive now unprotected connections.

    JB
    Yeah, I've seen that this happens on other cameras. But I think on Komodo it is more serious because it only has SDI out (I guess wifi or the link adapter count as video outputs, but neither seems to be rock solid). Also, there seem to be a large number of people with this problem. I'd estimate I've seen about 10 people commenting on the Komodo Users facebook group about SDI issues with their cameras, and I've only been following the group closely for a few weeks. Assuming for every post I've happened to see there are 4 that I missed (or that didn't post here or on FB), that's 50 out of around 10000 cameras in the wild (estimated from my very recently shipped serial number). That's a 1 in 200 failure rate, which does not seem too bad until you take into account that the average age of all the Komodos in use is probably around 2 months.

    Disclaimer: obviously these are VERY rough estimates and only Red knows the exact number of cases of this issue. I would love to hear more from them about this - what exactly causes the failure? Do we need to worry if powering a monitor from its own battery? Do we need to worry when swapping a dead BP-9 while the other BP-9 is running the camera? What about when attaching/detaching the camera power cable with batteries inserted? I work in remote locations, so I need reliable equipment. For now, I'm going to follow the recommended order of operation as best I can, but it is a real worry.
    Reply With Quote  
     

  5. #55  
    Senior Member Alex Lubensky's Avatar
    Join Date
    Nov 2016
    Location
    Kiev, Ukraine
    Posts
    322
    Quote Originally Posted by Björn Benckert View Post
    Not sure. It sound crazy if every time power is removed or added video cables have to be unplugged... But that is as I understand what all manufacturers are claiming now, but I hope I´m wrong as it sounds nuts.

    Again I unplug batteries and cables all the time with our without power and don't think much about it. So maybe I´m just been lucky but yes, who have time for such precautions. I´m more worried the SDI connector would be worn out from all the unplugging.
    I'm certainly not pretending to be right or wrong here, I'm just sharing my experience of the things. For over a year now I have my whole rig pre-built and ready to roll inside a nanuk 960 case, with monitors, focus motors, SDI cables etc. - all readily pre-connected. Tv-Logic 058W is running through SDI directly into the cam, powered by a d-tap > dc-in cable, running off a d-tap splitter. The d-tap splitter is connected to the d-tap port of the ID-X V-Mount plate on the back of my camera. Camera is running from a v-mount battery on this plate, and the same v-mount battery is feeding power of every each accessorie. I just plug the battery in and start rolling. I do this at least 6 times a day on set, and have done this with cams for years now, never had an issue myself or know someone who has fried the camera this way. Build the rig, wire everything up first, snap the battery last - boom, ready to roll. But I know people who have done the other way around - while connecting the power cable (d-tap) after the sdi cable was connected and the battery on.
    Reply With Quote  
     

  6. #56  
    Quote Originally Posted by Alex Lubensky View Post
    I'm certainly not pretending to be right or wrong here, I'm just sharing my experience of the things. For over a year now I have my whole rig pre-built and ready to roll inside a nanuk 960 case, with monitors, focus motors, SDI cables etc. - all readily pre-connected. Tv-Logic 058W is running through SDI directly into the cam, powered by a d-tap > dc-in cable, running off a d-tap splitter. The d-tap splitter is connected to the d-tap port of the ID-X V-Mount plate on the back of my camera. Camera is running from a v-mount battery on this plate, and the same v-mount battery is feeding power of every each accessorie. I just plug the battery in and start rolling. I do this at least 6 times a day on set, and have done this with cams for years now, never had an issue myself or know someone who has fried the camera this way. Build the rig, wire everything up first, snap the battery last - boom, ready to roll. But I know people who have done the other way around - while connecting the power cable (d-tap) after the sdi cable was connected and the battery on.
    I do the same. My video canöes are always in. Never had an issue. But yes, cameras seams to have problems wirh this now. Im guessing the 12G cards are more sensitive.
    Björn Benckert
    Creative Lead & Founder Syndicate Entertainment AB
    +46855524900 www.syndicate.se/axis
    VFX / Flame / Motion capture / Monstro
    Reply With Quote  
     

  7. #57  
    Senior Member Alex Lubensky's Avatar
    Join Date
    Nov 2016
    Location
    Kiev, Ukraine
    Posts
    322
    Yup, they sure are! newsshooter article on the subject:

    "This is especially critical for cameras with SDI connections capable of SDI 6G or higher (even if set to work at lower bit rates like SDI 1.5G). Cameras with SDI connections capable of SDI 1.5G or SDI 3G can be protected more efficiently without decreasing the SDI signal quality."
    Reply With Quote  
     

  8. #58  
    Senior Member Alex Lubensky's Avatar
    Join Date
    Nov 2016
    Location
    Kiev, Ukraine
    Posts
    322
    I suppose it depends on the monitor used in case of Komodo. Due to lots of lighter rigs out there - I think most of the fried cams were powered via native Canon BP batts or smaller v-mounts, while the monitor had it's own battery plugged in - which is usually non-grounded (like NP-F batts are +- unprotected), thus people fried cams while changing the battery on the monitor
    Reply With Quote  
     

  9. #59  
    Senior Member Robert Hofmeyr's Avatar
    Join Date
    Sep 2009
    Location
    South Africa
    Posts
    841
    Quote Originally Posted by Alex Lubensky View Post
    I suppose it depends on the monitor used in case of Komodo. Due to lots of lighter rigs out there - I think most of the fried cams were powered via native Canon BP batts or smaller v-mounts, while the monitor had it's own battery plugged in - which is usually non-grounded (like NP-F batts are +- unprotected), thus people fried cams while changing the battery on the monitor
    Hi Alex. Can you explain a bit more or provide a link to more information about grounded vs non-grounded batteries? I was not aware that this was a thing. I was under the impression that the main issue was the opposite of what you are describing. I thought the ground loop was caused by using the same power source for the monitor and the camera, then momentarily connecting the positive before the ground. Are you saying it is safer to use one power source for both?
    Reply With Quote  
     

  10. #60  
    Senior Member Alex Lubensky's Avatar
    Join Date
    Nov 2016
    Location
    Kiev, Ukraine
    Posts
    322
    If you watch the Arri video regarding the subject once again - they are talking about the connectors specifically, not the power source. It states:

    "Camera SDI outputs can get damaged when an accessory is connected to the SDI output and is powered through an unshielded cable. All cameras, including all ARRI cameras and other SDI devices, can be affected by this."

    D-Tap as a connector only has 2 pins, + and -. Same goes for the Sony NP-F style batteries, they only have + and -. I suppose if + connects first, and the camera has it's own power, it's the same as if you plug the d-tap power of the monitor with sdi connected after connecting the power source to the camera.
    Reply With Quote  
     

Posting Permissions
  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts