Re: Canon R5 - major tethering problems - need urgent help
rstebler wrote:
I can con confirm that over the last two days in 3 photo bays that switching to our older Type A USB 3.0 active extension cables has fixed the tethering issues. We use the cheap monoprice Type A extensions as they are the same cable as tether tools. Side note - don't ever believe the Tether Tools hype on their cables. They are just rebranded cables that are 1/5th the price.
What really bugs me about this solution is that it uses 5Gb/s cables vs what's supposed to be 10Gb/s even though I don't really believe that the Type C tethering cables were actually providing 10Gb/s connections. I just ordered some USB 3.1 Gen 2 10Gb/s Type A optical cables to test out actual time differences of images loading into Capture One from the Canon R5 and the Fuji GFX100s. Next will be testing Type A USB 3.0 5gb/s cables vs Type A USB 3.1 Gen 2 optical 10Gb/s cables vs Type C Usb 3.1 10Gb/s cables on a Mac Studio. The type C issues are so disappointing when I was sold the magic of the 1 connector to rule them all and it has been a disaster with +15ft cables. Not sure if it's an issue with the R5's handling of USB C 3.1 or the cable manufacturers?
A longer wire has more capacitance than a shorter wire. That means that it takes longer or requires more power to move the signal level from low to high or from high to low. All else equal, one can get faster speeds over a shorter wire. Once upon a time long ago, I asked a contractor to force ethernet speed to 10mbs instead of 100mbs over a long wire and ended up getting better data speeds even though the contractor thought that the specs were the same for the two speeds.
if a type A USB connector will result in negotiation of a slower speed, then one might get faster transfers over a longer cable with a type A connector instead of type C. But, I am just speculating because it has been a long time since I have looked at the specification. You could read the specification yourself and make some guesses about how well the various hardware implements the specification and then choose cable length. Else, if a longer run is needed, then maybe the USB data stream could be encapsulated in another protocol and sent over glass fibre optics so that length does not matter. The higher level data communication protocol might also matter, for example it is SCSI for USB storage, but I do not know what the camera or the iMac try to use. Reading about how the protocol resends lost data might help with thinking about transmission speed versus throughput with some the data being resent possibly several times.
Data transmission depends upon capacitance, resistance, and the magnitude of voltage swings in the transmission medium.
I hope these old stories might be helpful to someone.