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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

Jacob Muller said:
Hi Everyone . Really concerned about that SDI port issue . Has i understand there is now very simple protocol to follow but very time consuming for real world film set .

My question is .
Would it be possible that IN camera '' RED KOMODO '' It self . To add a feature that will Cut power off or simpely disable the SDI port IN CAMERA . with a menue feature in a Update ?
Which will allow hot swap and keeping the sdi connected in any situations.

In my opinion its not possible but would make so much sens.

What do youguys think about it ?
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On a real world film set, people already are doing this with Alexa's, Canon C line, anything 12G.

The SDI connection is manual, it's not software controller-based.
 
I haven't gone through this entire thread, but from my experience with grounding issues is that they can manifest symptoms in areas that aren't related to the problem.. in other words, sure the SDI ports may be the point of failure, but the problem could be located in another part of the circuit. Troubleshooting these issues on complex circuits can be insanely time consuming, much less coming up with a cost effective solution that is easily implemented after you've committed fully to production. Not to mention all of the supply chain issues related to Covid-19 that have plagued every industry... The only reason I bring this up is that RED's own FAQ on the subject points to issues also arising from D-tap accessories, which (in theory) would be routed through a different part of the main circuit.

I don't wish problems like this on any company, but at some point one would expect a major coordinated communication campaign to their customer base via this forum and the facebook groups to address the issue. After the whole Jinnimag debacle, one would expect them to focus serious attention to any of their remaining paying customers concerns.

Again.. I haven't gone through this entire thread, so maybe all of this has been addressed... and maybe it was just a bad batch of SDI hardware, which RED can't control since they're just building cameras out of parts other companies are manufacturing... (like most other camera companies)... but it seems from other recent posts I've read on this forum that red hasn't made any sort of effort to communicate directly to the endusers... which... is disheartening to those of us who recently stepped foot into the world of the Komodo.

The image of the company is based on cool, tough, dudes with tattoos holding big heavy cameras... very Harley Davidson like... however... the customer base is far more diverse and sophisticated than the trite branding image that RED continues to portray. In other words, the vast majority of RED users I know are extremely intelligent people who just want an open and honest communication chain to the company they've been investing a ton of money into over the years.
 
Robert Hofmeyr said:
Regarding the isolators, according to the Komodo Users FB discussion, these will also work: https://www.bhphotovideo.com/c/product/843846-REG/allen_avionics_hd_vit_75_video_isolation.html. They are cheaper, but only work with an HD signal. Unfortunately it is hard to know if this is the best solution until Red chimes in. I have emailed support. Perhaps they will respond.
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I don't mind an HD signal at all especially if it means not having to worry about frying the SDI port. I just don't understand why they can't tell us if this solution works or not. I hope they're not moving on from the Komodo and focusing on the Raptor
 
Isolators are typically effective for 3G SDI, not the 12G SDI needed for UHD/4K signals. In theory you could set the SDI output to HD@3G and use an isolator for protection. The 3G signal should be robust enough to "get through" the isolator. 12G over copper coax is a heavy lift even without adding an isolator, which is why even high spec cables often fail to deliver a feed.

Disclaimer: I have not personally tested any of this on an actual Komodo, my notes are based on specifications and anecdotal reports.

Cheers - #19
 
I’m using the 3G Len isolator between cam and Teradek, having the output set to HD. Works great.
I haven’t tested it with longer cables though, but I assume any cable length you will find around your camera will be fine.
 
This is a very informative read, cleared up a lot of confusion for me about the underlying issues:

https://rencherindustries.com/blogs/technical-advisories/hot-plugging-devices-on-arri-cameras


In summary, as I understand it now, there are at least three separate issues that can cause high current to flow through a BNC connector's center pin and burn out the SDI driver chip on a camera:

1. When plugging in unshielded cables to SDI accessories there is the risk of the positive pin making contact before the negative, which can cause high current to flow through the BNC connector's center pin
2. When powering on SDI accessories they may momentarily draw very high currents, which can also cause high current to flow through the BNC connector's center pin
3. Damage to the shields of an SDI cable can also cause high current to flow through the BNC connector's center pin

There also appear to be some nuances on how unsafe P-tap cables are to use for accessory power. The connector itself doesn't have a shield, which makes the P-tap connector unsafe for hot plugging (plugging in/out while there is a power source connected). However, cables using P-tap connectors can have the cable shield connected to the negative pin on the P-tap connector and that does allow the cable's shield to function while the connector remains connected. (Again, this does still not make the P-tap connector safe for hot plugging.)
 
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Bought a LEN 12G 4K SDI galvanic isolator and will be using that to mitigate any potential for shorting. It definitely works with the full 12G signal to my Ninja V and I can record DCI4K on the Ninja V via this setup. Now I just need to figure out how to route the wiring and isolator in a nice manner so it's out of the way. Cost is about the same as Red's SDI repair but it means I'm not down when I most need it, which in the end is the most important thing.

Cheers,

Paul :)
 
Potentially beginner question - can i use a high end 3g SDI cable to feed a 3G monitor without risking damage to the komodo. I know Red says to use shielded 12g cables, but I'd like to know what my options are
 
K. Rixon said:
Potentially beginner question - can i use a high end 3g SDI cable to feed a 3G monitor without risking damage to the komodo. I know Red says to use shielded 12g cables, but I'd like to know what my options are
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3G cables tend to have thicker cores, which can lead to splining (splitting of the internal connector center pin) and lead to more frequent/permanent signal dropout. Stick with 12G, they'll last you longer too! The light thin 3G SDIs are nice but prone to failure IME
 
Tim Szczesniak said:
3G cables tend to have thicker cores, which can lead to splining (splitting of the internal connector center pin) and lead to more frequent/permanent signal dropout. Stick with 12G, they'll last you longer too! The light thin 3G SDIs are nice but prone to failure IME
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Thanks for the advice. I'll try and stick to 12g. Is there a 12g cable that people prefer for gimbal work? I just got my Nine Volt 12g SDI cable in the mail and i worry its a little rigid for this purpose
 
K. Rixon said:
Thanks for the advice. I'll try and stick to 12g. Is there a 12g cable that people prefer for gimbal work? I just got my Nine Volt 12g SDI cable in the mail and i worry its a little rigid for this purpose
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I'm also interested in flexible recommendations. Also have the Nine Volt cables, and they seem solid and reliable but not very flexible. All the thinner, cheaper, "12G" cables I have purchased have failed.
 
L-2.5CHWS from Canare is king. Flexible, 12G rated and reliable. We make tons of them at Lentequip and can help you.
 
From the main page go to "Shop, Camera Accessories", in the first row at the far right is the mini video cable. Once on that page you use the dropdown to select regular mini video cable or the HD version. It's the little carrot in the box above the quantity selection. Sorry if it seem complicated, we are bound by the store's theme. Photo link attached to show you where it is.
You can also put LC-120HD in the search box and it'll take you to the cable where you select the HD version in the dropdown.
I've now added it to the front page in the "new" section as well to make it easier to find.
LC-120HD.jpg
 
I second the 12G Canare cables. Bought a 2' one from B&H that works great. Item number is CAL33CUHD002
 
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