C100: AV Out

M

mhood

Veteran
I hooked up an AV cable (with the 3.5mm 3 rings male to three RCAs yellow composite video and red and white audio) but couldn't get a video signal on the composite input of a monitor. The HDMI is working fine. I'm being asked to feed my signal (that I'm recording) to an overflow room and am not too sure what is the best way to go about doing that with a C100.

Is it not a typical AV cable for the C100? I have no idea how far my run will need to be. Should I convert HDMI to SDI (expensive) or maybe simply DVI (a cheap converter)? The feed will go to a projector and audio is not my problem.
 
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Try flipping around which RCA plug is going into the monitor. I have a few cables that are different, meaning that the Red or White RCA carries the video. I think this is caused by the 1/8" TRRS connector having a different configuration that varies by manufacturer.
 
FYI, the "Yellow = Video, Red = Right audio, White = Left audio" (as in the silly marching 'left, white, left, white' to remember it) is a pretty universally adopted standard, and I've used the Sony cables on Canon and Panasonic. LOL

And, FWIW, remember that the AV output is just standard definition. For anything more than a desktop run, I'd recommend getting 75 Ohm co-axial cable terminating in BNCs, and use an RCA barrel and an RCA Male to BNC Male (the one with neck bolts) adaptor. Then TAPE the buggers together once you've attached the long-run co-ax cable. Finding reels of 75 Ohm Co-ax to rent isn't so hard or expensive, and of course works just fine with HD-SDI too.

There are optical adaptors with fibre-optic cables to extend the reach of HDMI - a friend rents one in regularly, so much so that he's probably going to have to buy one (not a cheap solution though!). Anything over 60 feet on 1080p and things get a bit icky. I generally draw the line at half that. I did look into Cat-5e adaptors, which make for a far more easy-to-route cable (going up and over doors, taped down to carpets, fitting though 'mouse-holes' etc), but that's when we get to the next solution.

I'm more comfortable going with HD-SDI going forward, so an Atomos converter is a happier solution.

It depends on the type of work you're doing. If it's domestic event stuff (church, wedding, small scale meetings), yes - composite video might do but you're not going to be able to really charge for it, and although you're not doing sound this time, it will inevitably crop up. It's a lot of hassle for virtually nothing extra (other than 'getting the job' perhpas?)

So putting the business hat on, if it's a one off job, it's a hodge-podge of adaptors and a way of finding a long reel of co-ax cable. If it's a business thing, rent the gear in (though that won't wash on church/wedding stuff). But if you're regularly working with Pro AV companies and installations, HD-SDI over 75 Ohm co-ax. It's what it was designed for. :smile:
 
MattDavis said:
If it's a business thing, rent the gear in (though that won't wash on church/wedding stuff). But if you're regularly working with Pro AV companies and installations, HD-SDI over 75 Ohm co-ax. It's what it was designed for. :smile:
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I will have AC at the camera...no need for a battery powered HDMI-SDI converter. Atomos or BlackMagic...any others? The help is gr8ly appreciated.
 
AJA do one too. Don't forget Atomos' new mains powered converter: http://www.atomos.com/connect-ac/

Even though you have AC, I'd still keep the battery operated one in mind - especially if you're paying for one and thinking about 'the next job'. The H2S has a built-in battery lasting only 2 hours, but put an NP-f on it and you've got at least 12 hours of operation. And you can power it from USB (little adaptor plug plus a USB to Mini-USB) - so it is mains powered after all!

Not that I'm schilling for Atomos. LOL - I've had plenty of use of the mains powered Black Magic and AJA converters, though these are provided for me by the client (a webcasting company), so it's just another box dangling from the tripod. Mostly BlackMagic.

DataVideo do the DAC-9P - and that P is significant. You're looking for something that delivers a proper progressive HD-SDI signal, because HDMI at 1080 is an interlace thing. The converter needs to know about 3:2 and 2:2 pulldown processing.
 
The Atomos seems to make the most sense (to me right now). It does the pulldown automatically and I can AC power it (if need be) via USB. Would one of those phone usb AC power thingies work? I really think 30P is plenty...I don't know why I would need 60p to feed a projector. Thank you so much for the good advice.
 
Yes - a phone USB AC power thingy would work. They all deliver 5v.

But the sentance 'I don't know why I would need 60p to feed a projector' bought on a little 'frisson'. Is somebody ASKING for 60p?

I bring this up because I've shot stuff around high-end AV all over the place, and those guys just love 720p60. I have a great client in the UK who does high end webcasting, and they want 720p50 - and my C100 doesn't do that. That's when they break out the Blackmagic box, which downconverts my 1080i50 to 720p50 whilst also converting it to SDI so it hits their vision mixer in its happy place. Even on the smaller jobs, I'll be asked for Standard Def but 50i (this is using my EX1-Rs). If I give them 25p, they moan a bit because it's not as smooth as 50i/50p.

So... When you project an image large upon the screen, judder does show up a little more, and so big screen folks outside of narrative/cinema (who can plan their shots) are the ones demanding high frame rates on live stuff. Strangely, it doesn't seem to matter too much if it's an edited piece at 24/25/30, just the live stuff. Go figure.

But yes... Still warmly favouring the Atomis H2S but on the proviso that one is not contracted to delivering 720p50/60. Sorry to sow any seeds of doubt - just thinking out loud.
 
MattDavis said:
Is somebody ASKING for 60p? ... But yes... Still warmly favouring the Atomis H2S but on the proviso that one is not contracted to delivering 720p50/60. Sorry to sow any seeds of doubt - just thinking out loud.
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Nobody has requested 720/60p or 1080/60p. They are just asking for "a feed" from my C100 in the main ballroom to a projector in an adjacent overflow room. I'm thinking the Atomos would be a nice addition to my portable setup and if I encounter anyone in the future who demands 60p, they can supply the correct converter. The Atomos looks good, right? I record at 30 on my C100.
 
Sorry mate - mea culpa.

Here goes: Anything over HDMI that's 1080 lines high goes interlaced, and interlaced signals in your neck of the woods use 60 fields per second. Because you're sending 30 frames down the pipe, the HDMI bit splits each frame into two fields, and sends them as interlace. Of course, those two fields need to be glued back together at the other end, lest any device get fooled into thinking it really was interlaced to start with. Hence this '2:2' flag - two fields need to be combined back to a frame at the end.

Contrast and compare to 3:2 where you're trying to get 24p down a 60i pipe. At some point there will be a 60i frame that contains the fields from two separate frames (google 3:2 pulldown for some more visual explainations), and so the 3:2 flag helps get true 24p out of the HDMI cable.

So 'kit that plays nice' (like the Atomos, AJA and BlackMagic) has this 2:2 and 3:2 pulldown flag. Lesser kit does not have these flags and much milk is spilled and cried over. Egad, I think all this waffle is actually obfuscating the issue here. LOL - Let's say this: it will work. It's all down to magic smoke.
 
"Magic smoke"...Yea...that's something I'll be happy to pay for. Thank you Matt for the excellent advice.
 
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