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  • Hey all, just changed over the backend after 15 years I figured time to give it a bit of an update, its probably gonna be a bit weird for most of you and i am sure there is a few bugs to work out but it should kinda work the same as before... hopefully :)

The SDI issues

Found this on B&H:

https://www.bhphotovideo.com/c/product/1405164-REG/arri_k2_0015840_v_mount_battery_plate_with.html

V-mount plate with 6x power distro that includes a short run battery - lithium free BTW - as a Hot Swap Buffer. Something like this, only lighter duty since the Komodo and a small monitor need less juice. I'd also limit the regulated power taps to 3, rather than 6. Size and cost should be matched to the Komodo form factor/user profile.

Ultimately, I'm searching for a way to keep any electrical issues away from the SDI port/board. Putting a galvanic isolator, or anything else for that matter, in the signal path could inhibit getting a stable UHD signal to the display. When 12g was first introduced I was surprised. There had already been issues with the 1.5g SDI to 3g SDI transition, 12g on BNC/coax seemed ambitious. Since signal integrity and electrical isolation are both goals, I'd absolutely want high spec 12g SDI cables.

Cheers - #19
 
Alex Lubensky said:
Yes, it does go anywhere, if there's a minus already connected somewhere in the system, and the SDI cable is the bridge - like you have a battery running the camera already, and connecting a power source to the monitor - or vice-versa
Click to expand...

But a circuit will not be formed, so I'm failing to see how power will flow from the positive of the aux battery via the SDI to the negative of the main battery. Where does the power go from there? How is a circuit formed?
 
michael fetner said:
What would be the benefit from using the 3G Isolator for 200$ Vs the 12G Isolator for 500$? Does the 12G one allow your monitor to have a higher resolution or something?

I just purchased the 3G isolator last week - before I knew there was a 12G one. Curious what the resolution difference would be, or what the perk would be for double the price
Click to expand...

And it works? Are you working with a monitor that has an onboard battery separate from the camera battery? Do you keep that connected while changing batteries?


Dana Neibert said:
While all the videos/write-ups are correct in showing how to avoid this mishap, they make it seem more complicated than it really is and everyone freaks out trying to remember the order of operations to prevent frying the SDI controller—like the guy in a movie trying to defuse a bomb.

The way I remember is that no SDI cable should be connected while connecting or disconnecting power. That act of connecting or disconnecting power is what creates the dangerous situation. Once, power is established, you can connect or disconnect SDI cables all you want as they are not the the culprits in frying the system.
Click to expand...

The problem is not that it's complicated, the problem is that it introduces an impractical waste of time when having two battery components on the camera. On a normal film set, you are running the camera constantly, you never shut it off, which means you need to change batteries often. If you, as I mentioned before, shoot something where the last shot might be getting that sunset just at the rim of the horizon, or the child actor starting to lose interest and patience, you really can't be bothered with cable management, disconnecting the SDI, then change the batteries, then connect the SDI, start everything up etc. You need to get that freakin shot or you'll miss it. This is why tech engineers will never be able to convince creative people on time-consuming processes. This is why people demand shorter startup times of their cameras. It's not that they think the startup or cable management is booooring, it's because it can make or break a shoot, it could be the difference of getting a memorable shot for their movie, a performance that was surprisingly good and elevate the work to another level. When tech gets in the way of creativity, it's not a good tool for the job. So the tools must be better and follow the needs of the creative person, not the other way around.

Not to mention wearing out the connection by constantly connecting and disconnect it.

There has to be a solution where the SDI cable is constantly connected, regardless of changing batteries or whatever. If the demand is to follow the procedures at the connection and disconnection of the SDI cable, that is fine, that happens around twice a day on a set. But the cable should be able to sit attached while turning the camera and monitor on and off, changing batteries etc. I mean, just think of all the times when batteries run out by mistake on a camera. There are so many situations where things can't be followed like they do in the lab of the camera manufacturer. Film sets are messy, they are chaotic and the tech should be shielded from that as much as possible.

So far the only thing I've seen is the isolator being a viable solution. But it's unconfirmed and as long as Red doesn't confirm anything we're left hoping our cameras won't be fried.
 
Blair S. Paulsen said:
Ultimately, I'm searching for a way to keep any electrical issues away from the SDI port/board. Putting a galvanic isolator, or anything else for that matter, in the signal path could inhibit getting a stable UHD signal to the display. When 12g was first introduced I was surprised. There had already been issues with the 1.5g SDI to 3g SDI transition, 12g on BNC/coax seemed ambitious. Since signal integrity and electrical isolation are both goals, I'd absolutely want high spec 12g SDI cables.
Click to expand...

Are you using longer cables for 4K signal recording? I think the galvanic isolators might be a good solution for on-camera monitors. Shorter cables and the isolator shouldn't produce problems. I believe that a longer cable can introduce issues for that. You also have the 12G version of the isolator, a pretty hefty price at $500, but better than repairing at Red, if it works that is. I'm wondering if the isolator for HD signals works with 12G cables. If I were to put a right angle connector to the camera, then the isolator, then a 12G cable to a monitor using its own batteries. That should be a rock-solid defense against damage, right? If not that, why aren't there any breaker box-type adapters? Wouldn't it make sense to have something that breaks the signal if any high current gets introduced?

If not Red, are there any other experts on SDI technology that knows if these galvanic isolators are good insurance against damage? Or if they're just a waste of money?
 
I got some feedback from Red support, but I'm afraid it seems to just add to the confusion. They keep referring to powering off the camera and monitor when adjusting or removing the SDI, but don't mention disconnecting the SDI to change a battery. Red's answers in bold:

1. When you refer to "the power source for SDI accessories" does this include monitors being powered by their own battery?
Yes, please power off the monitor when adjusting or removing the SDI even if the monitor is on battery power.

2. In the warning in the manual you seem to be referring to any battery powering the camera or monitor. Is this the case?
Yes

3. Must I follow this order of operation when changing a BP-9 on the back of the Komodo, when there is a second BP-9 powering the camera?
BP Battery or Direct DC in, the KOMODO should be powered off when adjusting or removing the SDI.

4. There seems to be some confusion over whether this is a ground loop issue (eg the camera and monitor have the same power source and you plug in a d-tap to power the monitor and the positive makes contact first) or a differential grounding issue (eg the camera and monitor have different power sources, with different ground voltages). Please clarify what the issue is so I can do my best to avoid it.
Yes, this may cause a grounding loop. When possible, avoid using P-Tap (also known as D-Tap) cables to power accessories. These cables are not shielded and may damage your camera.
 
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Robert Hofmeyr said:
They keep referring to powering off the camera and monitor when adjusting or removing the SDI, but don't mention disconnecting the SDI to change a battery.
Click to expand...

It seems like they just read from a manual of answers to these questions and not really answering the questions you asked... sigh
So no luck there I guess. We just have to hope we get some answers in here then. It's like they see these posts but they just ignore them or something, and I don't understand why. Maybe Red's switching policies, no longer present on these forums as before and just focusing on a more closed group somewhere where they keep the discussions going. Can't really blame them if that is the case. Seeing just how the lower price of Komodo introduced a lot of amateurs to becoming Red owners, it also introduced a tsunami och idiot questions that just produce a deafening white noise throughout the Red community. So maybe they bailed this place because they don't have time to care for the mass and instead focus on a more closed group of testers and their technical issues.

But that's just speculation of course, we don't know anything, it might just be the covid situation, but I'm thinking that would increase presence online since most of us work from home nowadays. I just want to know some solutions to this, more of a deep dive, not some re-telling of the manual's vague description that really isn't what we are asking about. It's like the computer support where the only answer you get is to "restart the computer" like that's not the first thing anyone has ever done before contacting support.

Just want to know a simple yes or no from Red about the galvanic isolators. Do they work? Do they prevent damage when the procedures can't be followed or don't get followed due to the situation of filming? If yes, GOOD then we have a solution to this entire thread, if no, then we have to continue figuring stuff out.
 
Christoffer Glans said:
It seems like they just read from a manual of answers to these questions and not really answering the questions you asked... sigh
So no luck there I guess. We just have to hope we get some answers in here then. It's like they see these posts but they just ignore them or something, and I don't understand why. Maybe Red's switching policies, no longer present on these forums as before and just focusing on a more closed group somewhere where they keep the discussions going. Can't really blame them if that is the case. Seeing just how the lower price of Komodo introduced a lot of amateurs to becoming Red owners, it also introduced a tsunami och idiot questions that just produce a deafening white noise throughout the Red community. So maybe they bailed this place because they don't have time to care for the mass and instead focus on a more closed group of testers and their technical issues.

But that's just speculation of course, we don't know anything, it might just be the covid situation, but I'm thinking that would increase presence online since most of us work from home nowadays. I just want to know some solutions to this, more of a deep dive, not some re-telling of the manual's vague description that really isn't what we are asking about. It's like the computer support where the only answer you get is to "restart the computer" like that's not the first thing anyone has ever done before contacting support.

Just want to know a simple yes or no from Red about the galvanic isolators. Do they work? Do they prevent damage when the procedures can't be followed or don't get followed due to the situation of filming? If yes, GOOD then we have a solution to this entire thread, if no, then we have to continue figuring stuff out.
Click to expand...

I agree. It would be great to get some proper feedback that we know is correct. I'm currently just listening to whoever sounds the most convincing online :). And if my (admittedly very rough) estimates below are even close to correct, then this is a more serious problem than it has been on other cameras.

Robert Hofmeyr said:
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.
Click to expand...
 
Those replies from Red are contradicting them selves, so yes cant really be from a person that knows what they are talking about.

I'm sure this will be sorted on the next gen of cameras. As for komodo / LF gen I think it is what it is, in other words a lot of SDI boards will fry.
 
It seems to me that Red Technical Support's guidence went beyond what is stated on page 141 in the Komodo operations manual. This is not helpful and certainly adds to confusion. This is a problem known to Red and needs to be addressed in writing by either a manual revision or an alert bulletin emailed to Komodo owners immediately.
 
Robert Hofmeyr said:
3. Must I follow this order of operation when changing a BP-9 on the back of the Komodo, when there is a second BP-9 powering the camera?
BP Battery or Direct DC in, the KOMODO should be powered off when adjusting or removing the SDI.
Click to expand...

So when we change the battery, the SDI shouldn't be connected. And when we disconnect the SDI the Camera should be powered down. Now we have to switch off the Camera every time we change battery?? I'm sure that can't be right they wouldn't design a camera with hotswap feature if you cant use it, would they? :biggrin5:. I also think RED should help us out here and explain again what exactly the correct sequence for connecting/ disconnecting cables/ powering on and off is and for wich scenarios a galvanic isolator is beneficial.

Christoffer Glans said:
It's like... hey, we have some worries about the SDI integrity, could the 12G galvanic isolators prevent damage when procedures or changing batteries happens fast on location so as to not risk damage when unintentionally breaking procedures or just changing batteries in a normal fashion that doesn't take an impractical five minutes of cable workflow?
Click to expand...

According to this article, at least when using D-Tab connectors the routine should be maintained even when using an SDI Isolator.

https://www.newsshooter.com/2020/02/15/preventing-damage-to-sdi-outputs/

Here's the part (last sentence)

"When connecting: FIRST connect power cables, THEN BNC.

When disconnecting: FIRST disconnect the BNC, THEN the power. Also helpful is using shielded power cables and avoiding D-tap connectors.

To further protect the SDI outputs, an SDI isolator can be used. Please note, that SDI isolators can reduce signal quality and/or maximum cable length.
D-Tap (also called Power-Tap or P-Tap) connectors are made out of plastic and therefore cannot support a shield. Cables with D-Tap connectors should only be used when the above-mentioned cable connection sequence is followed.
 
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Amarin Spörri said:
So when we change the battery, the SDI shouldn't be connected. And when we disconnect the SDI the Camera should be powered down. Now we have to switch off the Camera every time we change battery?? I'm sure that can't be right they wouldn't design a camera with hotswap feature if you cant use it, would they? :biggrin5:. I also think RED should help us out here and explain again what exactly the correct sequence for connecting/ disconnecting cables/ powering on and off is and for wich scenarios a galvanic isolator is beneficial.



According to this article, at least when using D-Tab connectors the routine should be maintained even when using an SDI Isolator.

https://www.newsshooter.com/2020/02/15/preventing-damage-to-sdi-outputs/

Here's the part (last sentence)

"When connecting: FIRST connect power cables, THEN BNC.

When disconnecting: FIRST disconnect the BNC, THEN the power. Also helpful is using shielded power cables and avoiding D-tap connectors.

To further protect the SDI outputs, an SDI isolator can be used. Please note, that SDI isolators can reduce signal quality and/or maximum cable length.
D-Tap (also called Power-Tap or P-Tap) connectors are made out of plastic and therefore cannot support a shield. Cables with D-Tap connectors should only be used when the above-mentioned cable connection sequence is followed.
Click to expand...

The issue isn't really using D-Taps, because you can use lemo's instead. I would argue that it's fine that we don't use D-taps at all for our monitor, that could be a limitation we can't get around. But power through lemo, or better, powering a monitor with its own batteries, should be totally safe with the isolator. We should be able to just have everything plugged in with that isolator, turning camera and monitors on and off however we want and changing batteries however we want. That is required in order to be able to go through a day of shooting without having creativity being blocked by time-consuming cable management.
 
I noticed that the Cinegears Ghost-Eye wireless transmitters specify they provide +/- 8kv ESD protection on all input and output connections. If a Ghost-Eye (or similarly equipped transmitter) is the first unit in the output chain of a Komodo output will this not help mitigate the problem or does it only protect the transmitter?
 
Based solely on web research, the:
https://tilta.com/shop/dual-canon-bp-to-v-mount-adapter-battery-plate-for-red-komodo/
looks like an excellent way to route all power through a single device. Compact, reasonable price, 2x D-tap and 2x 2 pin power outs - and it mounts directly into the dual BP-9 slots.

Has anyone using this plate fried their SDI board? In theory, at the point of attaching a fresh V-mount battery, if the + pol mates first, a power blip could still fry the SDI board - unless there is something inside the plate that stops it. Does anyone know the skinny on this? Is it as simple as having a relay in the plate that doesn't feed power to anything until it sees both + and - are there?

I suppose the brute force solution with the Tilta plate might be using batteries that can piggyback on each other (IDX, Core, etc), just don't let the inside one go dead and swap the outside one as needed - of course size and weight would be sub optimal.

Cheers - #19
 
Blair

I have this Tilta V-Lock plate and I really like it. I have done a slight modification to the D-Tap receptacles on the plate by taking a #30 drill and on the + female on both D-Tap connectors and drilled in about 1/8 inch. By doing so, the - pin on the connector must make contact first. I did the same on all of my V-Lock batteries + side with a #31 drill so they also must make make a connection with the - pin first. Your relay idea is very interesting, however.

I still follow the connection sequence stated in the WARNING on page 141 in the Komodo operation manual and have placed warning lables on the Tilta V-Lock plate, batteries and on the AC adapter in conspicuous places with yellow tape.

Murphy's Law is always lurking on the set and on location.
 
Forgive me if this was already explained here, but why is this an issue for some camera models but not others?
 
Good question. Was this or is it currently a significant problem with DSMC 1 for instance which is limited to 3G HD-SDI?
 
It's all the cameras out there with SDI.
I've seen fried SDI boards on Alexa Classic, Mini, LF etc just as often as on any other camera. BTW, the more cameras out there on rentals- the more fired SDI's you know.
 
John David Pope said:
Forgive me if this was already explained here, but why is this an issue for some camera models but not others?
Click to expand...

It seems to be an issue with all 12G SDI cameras. But most other cameras have multiple video outputs, so if you blow an SDI you can keep shooting. I do think there do seem to be a rather high number of failures on the Komodo - perhaps the board has less protection than on other cameras?
 
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