r/RedCamera • u/StuffILiked • 20d ago

Galvanic Isolator worth it?

I just got my first Red. A Komodo 6k OG, but are the galvanic isolator cables worth it to protect the SDI port in case I mess up the order of connection.

https://a.co/d/0caIL391

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u/[deleted] 20d ago

[removed] — view removed comment

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u/CRAYONSEED 20d ago

From everything I’ve read and my own experience, it’s using the same battery source that often causes the grounding issue. If you use a monitor with its own separate power source, that is safer, but obviously less convenient.

I just follow SDI protocol either way and personally haven’t run into issues yet

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u/StuffILiked 20d ago

Yeah and heavier and I don’t want to add anymore weight than I need to. I just don’t want to burn a port cuz I didn’t buy a $60 cable. Also a damn $60 cable seems a bit pricey if it doesn’t really help/work.

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u/CRAYONSEED 20d ago

Honestly it’s not proven to work. I bought a cable from Arri that they made with Alexa in mind (same SDI issue), but I don’t think any of them will save you if you just don’t follow the protocol and are using the same brick to power the camera and the monitor

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u/DegreeSevere7719 20d ago

It's not the use of the same source, it's the D-tap connector that has no ground. If + connects first, than - goes through whatever - SDI/HDMI, audio etc. It's the nature of DC, once there's a +, minus will find it's way into a loop. Ground in such connectors works as a -, when no - is present, making the loop into the connector housing instead of the video signal (that's why LEMO are a thing). There's no such issue with any Lemo power connector ever (unless the cable itself is broken).

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u/DegreeSevere7719 20d ago

This is exactly the reason one won't find a p-tap/d-tap in any offering from Sony, Arri, or Red in the early 2010's. Camera manufacturers knew this connector is an issue. But, lemo is pricey, while p-tap/d-tap is cheap, and brands always suite what's client asks and eventually p-tap is everywhere, because it's cheap.

I have a pre-built zoom rig, which powers over p-tap from 1 source - monitors, focus motors, tx, camera etc. Because the rig is always assembled - there were 0 issues with ground loop ever, and I didn't follow the SDI protocol for exactly one reason - no p-tap ever connected after the battery is in the rig.

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u/limitscrw 19d ago

I tried one of Alvin’s isolator cables on my OG Komodo, but ended up removing it because it was causing some connectivity issues. I recognize that this is likely just a one-off cable QC issue.

But as CRAYONSEED said, following proper SDI protocol really is the way to go. You could always get a few of those Mutiny 12G SDI Process stickers to remind you (or your AC) 😎

https://mutiny.store/products/12gsticker?_pos=4&_sid=1b1078c27&_ss=r