Electronics > Beginners
Testing 12G-SDI cable
<< < (3/3)
rx8pilot:
I have been in this industry for decades, and now design 12G gear.

The short answer is that it is very expensive to test anything. A Leader or Phabrix with eye pattern option and payload analysis is by far the easiest. They can show the signal integrity, errors, and a description of the payload. You can see impedance issues, although you will not know where they are. You will see the amplitude, eye width, hight, rise and fall times.

The only problem is that for 12G, I think they are around $15-20k or so with eye options. You can also get a VNA for twice that if you really want to look close.

shoulderkey:
Just had to reply to a few things:

"BMD the Bheringer of broadcast!"

Most broadcast cameras in use aren't Arri Alexas. They're old Sony HD (at best) cams.

"Nobody shopping BMD has any actual need for 12G :palm:"

BMD Ursa cameras (since 2014) push out 12G-SDI for 4K RAW or ProRes consistently and reliably. The quality is up there with the Sony FS7 or Red's. Sure it ain't no Arri or Red Helium, but look at the price tag.

"I mean the glass you need to actually manage to capture 4K, never mind the sensors means that even if you are shopping GV or the like you probably don't bother with the 4K option for most things."

The Sensors capture 4K quite effectively. BMD uses Fairchild Imaging LTN4625A sCMOS sensors for the Ursa. They can do 12MP at 120FPS with Global shutter at very low noise. I'd wager that this sensor is better than the Arri Alexa SXT sensor (ON Semiconductor designed ALEV III sensor). The difference is Arri has in camera Fixed Pattern Noise control and far better native ISO. What they do with a less capable sensor beats the competition hands down. On BMD you have to remove your FPN in post.

They fill up a 512GB SSD under 45 mins with 4K RAW.
BMD Ursa's uses EF/PL/MFT glass. Even the cheapest glass can resolve 8MP quite effectively (albeit with distortion and aberration)

"Yes, I know BMD advertise a "4K" camera but there is not much point in outputting 4K if the sensor and glass are not up to the job."

Who says it's not up to the job?



"I am not seeing much BMD in broadcast facilities (At least not in chain), churches, theatres, schools, wedding video types and conference centres seem to be where that stuff mostly lives in my experience."

Most traditional broadcast facilities are closing down. The few that are left of them are still using old Sony HDCAMs.
YouTube and streaming will replace all of them in the end.

Sorry for the necro.
Navigation
Message Index
Previous page
There was an error while thanking
Thanking...

Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod