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Why is firewire crushing my blacks?
Forgive the ignorance…
Normally, I output quicktime files to a hard disk which I give away, or I compress to MPEG2 and burn DVDs. However, now I need to output to a Sony DSR-20 DVCAM deck. I work with an AJA IO when monitoring/capturing footage, but I figured for this project it would be easiest to unplug the IO, plug in the deck, and firewire straight to tape.
However, it’s crushing my blacks.
Black levels on the timeline are fine, (viewed through an external monitor hooked up to the IO, as well as a LEADER digital waveform coming off the SDI out on the IO), however black levels on the DVCAM tape (via an analog waveform hooked up to a different deck) are tooooo low.
Is FCP dropping the setup on the firewire out? Or is the DSR-20 dropping the setup on ingest? Doesn’t make sense.
Did a kicks-and-giggles test outputting via IO, through S-video back into the DSR-20 and black levels are perfect. Of course, the video quality then suffers and the colors are desaturated.
If anybody has a little light to shed, or a “flip the switch you bonehead” answer, I’d be happy to take either.
Nick
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13 Replies
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Does the DSR-20 have an add setup menu setting? If it does and it’s not activated, that might be the problem.
Doug Olin
Desert Vistas Multimedia
http://www.desertvistasmm.com -
No, no add setup function in the menu, unfortunately. Technically, though, we shouldn’t need to add setup right? Since level is good on the timeline?
Nick
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No, you shouldn’t need to add setup. Some DVCAM decks have an add setup menu setting so you can add it, if desired.
Doug Olin
Desert Vistas Multimedia -
[Nick Ryan] “If anybody has a little light to shed, or a “flip the switch you bonehead” answer, I’d be happy to take either.”
Well, Nick, that’s because DVCAM is still DV and DV video has a zero setup, not the standard 7.5 IRE. I’m not familiar with that machine but check to see if you have a Black Stretch setting in a menu. If so, turn it on and that will bring your black levels to standards.
Don’t ask my why or whoe decided that DV was zero setup… Sounds stupid to me BUT that’s the standard for DV.
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Wayne Carey
Schazam Productions
http://www.schazamproductions.com -
All digital video has 0 setup. Not just DV.
7.5 is for analog video only. Most digital formats will add setup to the analog outputs so the video looks normal on a monitor, but the setup isn’t actually on the video…it’s just that particular output. I’m wondering, Nick, if your IO card is adding setup to your preview monitor. So, you’re looking at that and then the timeline (which has no setup) copies to the DV tape which you then view and conclude that your blacks have been crushed when really nothing’s changed…just your method of viewing the footage.
This is all guesswork on my part but that seems to be the most likely. Start by checking the waveform monitor inside of Final Cut. Does that match what you see coming out of the IO card? If it’s lower then my guess is right and there’s nothing wrong here.
What you need to do in that case is search the DVCAM deck’s menus for a way to add setup to the output. That won’t change the video ITSELF, but it will add setup to the analog output of the deck and then your monitoring of the timeline and your monitoring of the tape will match.
So to recap: Digital video SHOULD have 0 setup but any analog outputs SHOULD be adding 7.5 to the video as it goes to analog monitors. Search your workflow for any places where that doesn’t happen correctly.
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Yes that is true about the zero setup for DV.
As a note,
zero is the black setup standard for EVERYTHING in Japan
….and so this may be a clue.Anyway Good Luck.
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[Jeff Carpenter] “Digital video SHOULD have 0 setup but any analog outputs SHOULD be adding 7.5 to the video as it goes to analog monitors. Search your workflow for any places where that doesn’t happen correctly.”
True, Jeff. BUT let me shed some more light on this.
What you mention is all true of digital prosumer formats, when relating to broadcast digital formats such as IMX, P2, D2 and so on, they have a setup of 7.5 IRE. This even applies to DVCAM when the menu is adjusted for this. So, DV is a prosumer format desgined by the Japenese (who use zero setup) to be used my any Joe. It originally wasn’t designed to be broadcast in the US, just for comsumers to shoot in a digital format that was very cost effective.
SOOOOO…. to recap. Firewire was intended originally for DV and was designed that way. When you digitize using firewire on a DV or DVCAM machine, it wants the video to be of zero setup.
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Wayne Carey
Schazam Productions
http://www.schazamproductions.com -
Hmmm, good thoughts guys. Thanks! I’ll root around and see what I can come up with. I like the IO adding setup to the monitor idea… we’ll see what I can come up with.
Nick
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[Wayne Carey] ” when relating to broadcast digital formats such as IMX, P2, D2 and so on, they have a setup of 7.5 IRE.”
That’s not my understanding. There’s a good discussion of this issue on Ken Stone’s site written by Graeme Nattress, here:
https://www.kenstone.net/fcp_homepage/video_levels_nattress.htmlRegards,
David -
The DSR-20, the DSR-30 and I think the DSR-11 do not and cannot add set-up on the analog outputs. I once asked a Sony engineer why, and his reply was that on a low-end $3000 deck, we can’t include everything. Go figure…
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