[ANSWERED] usb c extension cable for webcam Logitech brio 4K whcih works fine on mbp

  • Re: [USB extension](/topic/515/usb-extension)


     for a drawn concert I need to get an extension cable USBC / USBC for the cartoonist to film his drawings in real time,  

    we use Logitech brio 4K on mbp13' 2017, 

    should we get a powered one? 

    thanks a lot !


  • Izzy Guru

    I would say yes. 

    It depends how far away the camera is from the machine - but there will be no harm in using one. 

  • Tech Staff

    I just want to preface this by saying that while your post is specifically about extending a USB signal, my advice below is relevant (for the most part) regardless of whether the signal you're trying to extend is USB, VGA, HDMI, DP, DVI, SDI, etc. My answer is kind of overkill for your specific question, but I'm hoping it'll be helpful for other people on the forum with similar questions about extending a signal over a distance.

    Do Research

    • Read the specs of the camera carefully; I seem to remember running into some cameras and devices that specifically say that they're *not* compatible with extenders.
    • Definitely read the reviews before you buy anything and don't buy anything for which you can't find reviews if you don't like to gamble.
    • Don't just buy the first thing that looks good. Be thorough in researching your equipment and read the specs to make sure it'll work for your intended purpose. When in doubt, you can try to contact the manufacturer or a rental house that has the same equipment you're looking at and ask them if they think it'll work for your use-case.

    Minimize the Distance Between the Signal's Source and its Destination

    The sneakiest and simplest way to minimize the amount you need to spend on extenders is to place your show computer as close to the camera position as possible. E.g.:
    • Camera onstage and show computer & video operator just offstage = a much shorter distance = less effort/money/equipment needed to extend the signal from the camera to the show computer.
    • Camera onstage and show computer & video operator in the booth at the back of the theatre = much longer distance = more effort/money/equipment needed to extend the signal from the camera to the show computer.

    If you plan on using any sort of wireless extender, (e.g. wireless HDMI transmitter gets attached to the camera, wireless HDMI receiver gets attached to the computer), you can also use a variation of this method by placing the wireless receiver above the center of the stage in the grid or on a batten to minimize the distance between the transmitter and the receiver, and then using wired extender (ethernet, SDI, etc) to extend the signal from the wireless receiver to the computer.

    If you need to go a reasonable distance and you *do not* have a big budget for extenders, consider using a laptop hooked up to the camera close to where the camera needs to be, wiring the laptop and your show computer to an ethernet switch, creating a Local Area Network, then using NDI to send the camera feed from the laptop to your show computer via LAN. Assuming you don't need to buy or rent a second computer, this option is one of the cheapest ways to do this.

    Active > Passive

    Active (powered) is better than passive (unpowered) in my opinion because some active extenders are designed to allow you to daisy-chain them together to cover a greater distance. In my experience:

    • Most passive (unpowered) extenders *cannot* be daisy-chained together. 
    • Only *some* active extensions allow daisy-chaining them together. 
    • Other active extensions specifically state in the specs that they *CANNOT* be daisy-chained together. 
    • If something doesn't say whether or not it can be daisy-chained, err on the side of caution and assume it cannot. 
    • Always read the specs carefully before purchasing, otherwise you may end up buying 3x 30m active USB extenders that can't be daisy-chained, forcing you to either find a new solution or re-think your setup so that your camera is only 30m away from your camera instead of the 90m you planned on.

    Extending Over Ethernet (low-tier - cheap, respectable distance, ethernet cable is abundant and cheap to replace)

    If you need to cover a reasonable distance (e.g. from the stage to the booth at the back of the theatre) or are touring a piece and need a flexible setup for different theatres, consider getting a powered USB-C-over-Ethernet extender. 

    • You get what you pay for with these, so in my experience it's best not to go for the very cheapest ones. 
    • The highest-priced ones are often overkill, so try to aim somewhere in the mid-range in terms of price. 
    • As a rule of thumb, the more expensive the [X]-over-ethernet extender, the longer the distance they can generally go and the more reliable they are. 
    • They type of ethernet cable you use matters! If you don't use shielded cables, you can end up getting interference if your ethernet cable crosses any other cables.

    Extending Over SDI (mid-tier - mid-priced [some overlap with ethernet price range], great distance, SDI cable is abundant but not always as cheap as ethernet to replace)

    • SDI is the go-to "pro" solution for extending signal because it is affordable and robust, (sometimes theatres will even have their own SDI run(s) permanently installed between the stage and the booth).
    • In my experience SDI has the best balance of quality-to-price.
    • SDI extenders tend to be higher quality than ethernet extenders.
    • Keep in mind that there are different "flavors" of SDI and you need to make sure to use the right one for the resolution and framerate that you intend to use

    Extending Over Fiber (high tier - very expensive, incredibly far distances, but can be fragile)

    • If you need to go a *ridiculously* far distance and you *do* have a big budget, look at USB-over-fiber extenders (some can go for miles). 
    • These tend to be very expensive and sometimes very fragile (so not always well-suited for rough theatrical endeavours). They're much better for permanent installs.

    Allow Time for a Test-Build

    It's a good idea to make sure you allow time in your production schedule to test-build your setup so you can try it out/work out the kinks before you have to have it up and running for tech rehearsals/performances. This way you ensure that you have time to find a different solution if your first combination of equipment doesn't work out. If you're considering buying high-end equipment, it's likely best to look around at professional AV equipment rental companies near you to see if you can rent the *exact* equipment you're considering purchasing and using the rental equipment for the test-build to confirm that it will work *before* you make a big purchase.

  • @wolandthanks a lot for this work ! 

  • Hi there,

    we use a 25m Usb Cable wit a built in repeater an a logitech C920 HD Pro. and it works really well!


  • @bennnid said:

    Logitech brio 4K

     There is a lot of great info in this thread, @woland gave a great response, and I wanted to add a few things to the information. 

    The extension options you choose will also be directly related to the bandwidth you are sending, and nothing is for free. signals sent over Ethernet extension systems will be quite limited in bandwidth, so even the mid to high tier HDbaseT extensions will make some sacrifice at higher resolutions- this is often in the form of shorter transmission distances (most 4K HDBaseT extenders drop their transmission distance a fair bit at 4k vs HD), and colour compression, most HDBaseT systems use 4:2:0 colour compression at pretty much all resolutions. This allows the manufacturers to use slower transmission and reception chips that are cheaper but can pass less bandwidth per second. This is where the high end expensive extension systems come into play. The other feature that the fancy HDBaseT stuff has is that it also modulates a network signal in the same extension over a single cable, this means when working with projectors that have a network port you can run a single cable and get signal and control.

    Also on the topic of ethernet and bandwidth, AFAIK there are no full bandwidth USB 3.0 over ethernet extension systems, standard ethernet cabling cannot support that much data. So in the case of @Bennnid and the logitech camera, if you use an extension system via ethernet you will be locked to USB 2.0 speeds and not be able to capture at 4k. USB 3.0 is still difficult to extend, there are some active extensions, some fibre based cables, these are all a bit problematic in my experience - fragile cables, expensive and not repairable. There are some full bandwidth USB 3.0 over fibre extension systems (newnex) that work well but they are expensive (upwards of €1000 for the boxes and cables). There are also a lot of extenders for USB 3.0 that support the protocol but not the bandwidth - this is a kind of cheap trick, again using slower transmission modulation chips that cannot deal with things like real time video. You will see your device when it is connected but speed will be slow and in the case of video it will choke on high bandwidth streams, or not initialise. So far it is often cheaper to use an NUC close to the USB 3.0 device and stream the data you need over a standard network in some way. Having said that I am currently using/testing some cables I got from a Chinese manufacturer that are giving me full bandwidth USB 3.0 (I am using kinect Azures and they are sensitive to errors as the data streams need to be assembled via timestamp) over 25m for around €100 per cable. BTW the cable that @gapworks linked to above is USB 2.0 only, so again limited bandwidth.

    To a large degree you do get what you paid for. The very expensive extension sets for HDMI over ethernet (or HDBaseT) will be able to transmit longer and are more stable, same goes for USB 2.0 over ethernet. I have been working in a space with Ethernet connections in moving trusses and patch panels throughout the room - some of the points are quite far apart (up to 75m), the cabling was done with high quality shielded cat 7 and the patch panels and cabling are high quality. We have been going through extension systems and checking their performance, and from what we see, the very expensive kits are the only ones that actually let us patch to and from anywhere in the room. The units that fail do communicate as to their spec but can only operate at lower bandwidth (of course we also check with other cables). At shorter distances the high end systems are overkill, but as soon as you need a longer distance you are forking out ~1k for an extension set.

    To reiterate one of @Woland 's points - cabling becomes very important. Not all cable is equal, 2 cables specd the same can give different results so test test test, especially Ethernet and especially at higher bandwidths.