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House sync...genlock...what the?

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Oli da Costa
House sync...genlock...what the?
on Oct 3, 2009 at 11:05:36 am

Hi, I run a small post company with 2 HD suites (1x PC, 1x Mac) and I've always been able to make do with hooking up VTRs for recording and digitising (everything from Beta to HDCAM SR) avoiding using the ref input/output on the VTRs and my systems (1x Axio HD and 1x BMD Multibridge Pro2), by simply telling the VTRs (via their unique and convoluted menu systems!) to use a reference from the input/output signal. However, yesterday, I had some really serious issues with an HDW-2000P and after talking to an engineer from the hire firm, surmised that having some sort of 'house' sync or genlock was a better idea.

What I gathered (rightly or wrongly) was that I should have a device than produces a constant sync signal, and that this should supply all the BoBs attached to my systems (Axio HD and BMD) as well as any VTR I hire in and that this would provide me with a more robust way of ensuring material I lay-off to tape would be in rock solid sync. Is that it, or have I got totally the wrong end of the stick!?

With the current 12 hours of HDCAM lay-offs I'm still doing, I'm using the VTR to do an assemble edit from my Axio and experiencing the VTR dropping the PGM onto tape exactly on the mark (10:00:00:00, as per usual), except sometime, it wanders and drops it in at, say, 10:00:00:05, so whilst the a/v is in sync with itself, the whole PGM is 5 frames late, and I fear the tapes might get rejected by the broadcaster! So, would having some sort of sync device solve this?

Sorry if this is a really basic question - and I'm somewhat embarrassed to ask it after doing this for 10 years - but it's something I've always known I should have, but never got round to asking before!

Any advice on makes, models, what to look for, pricing, etc would be very much appreciated! I'm guessing an AJA GEN10, or something similar would be what I need...but how and when should it be used?

Cheers,

Oli

Oli da Costa
Fraktiv Post Production
London W1


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Bob Zelin
Re: House sync...genlock...what the?
on Oct 3, 2009 at 4:30:29 pm

Oli writes -

I had some really serious issues with an HDW-2000P and after talking to an engineer from the hire firm, surmised that having some sort of 'house' sync or genlock was a better idea.

Sorry if this is a really basic question - and I'm somewhat embarrassed to ask it after doing this for 10 years - but it's something I've always known I should have, but never got round to asking before!

Any advice on makes, models, what to look for, pricing, etc would be very much appreciated! I'm guessing an AJA GEN10, or something similar would be what I need...but how and when should it be used?

REPLY -
what amazes me is that you have been doing this for TEN YEARS, and don't know what genlock, or a sync generator is. How have you survived all this time. From the beginning of time, external sync has been used. It has appeared on all professional equipment since Ampex 2" Quad VTR's (when they used external sync and subcarrier), and all thru the linear years, all thru the AVID years, and now into the FCP/Adobe days. All cameras, all switchers, all graphics products (like Quantel), all EVERYTHING has had external reference/genlock inputs. HOW THE HELL DID YOU GET THRU YOUR CAREER without using a black generator ?

I don't give a crap if you have been "lucky" all this time - you need a black generator. Your guess at the AJA GEN10 is an excellent guess - it is a fantastic product. As to where to get it, and how much does it cost - are you kidding me ? You have been doing this for 10 years - you work with professional video equipment ? Don't you have a dealer that you have been working with all this time ? And there is a NEW INVENTION on the internet - it's called GOOGLE. You type in http://www.google.com, and in the search window, enter AJA GEN10, and you will see LOTS of companies that will sell it to you, with the exact price of the product.

Do not eat any food, until you purchase a black generator to resolve your problems. Long after your Axio is obsolete, you will continue to use and make money from your Black generator investment.

Yes, all your problems will be over when you buy the black generator. Although I dont' know the Axio (Matrox?), I bet there is a menu to select EXTERNAL REFERENCE on it, instead of internal or free run. Make sure you select this.

Bob Zelin





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Oli da Costa
Re: House sync...genlock...what the?
on Oct 3, 2009 at 5:32:06 pm

Hi Bob...I appreciate your advice but I'm a little taken-a-back at your tone. Yes, I have been doing this for 10 years but I'm entirely self taught - I'm one of a select few Adobe UK freelance demo artists - and yes, I've survived for 10 years without one, producing very good, very cutting edge work for lots of very well known client and haven't thought that I had the need for one until now.

As for how I've managed until now, all the gear I use has always had some sort of an internal reference/genlock and as I never do any VTR-to-VTR dubs, etc, I've never considered the use of one of these. Only a very small fraction of my work involves tape lay-offs - maybe once every 6 months as most of my work is delivered tapelessly or via low-end DV/HDV formats or via the web, hence my lack of knowledge in this area. I appreciate you're a video engineering whizz but I wasn't expecting that sort of a tirade...

From having a scan of the brochures for these products - I've so far looked at the AJA, BMD and LYNX sync gens - I gather that you just plug em in to your suite(s) - disabling internal sync generation - and VTR, set the appropriate format and then go...is that it?

Oli

Oli da Costa
Fraktiv Post Production
London W1


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Baz Leffler
Re: House sync...genlock...what the?
on Oct 4, 2009 at 3:28:27 am

Oli - I don't know the Axio but I regularily do frame accurate edits to tape without genlocking the deck to reference black. I use Final Cut Pro and Blackmagic boxes into HDW1800 HDCAM decks (pretty much the same as the 2000 deck).

All I do is make sure the deck is locked to 'incoming SDI'. Edit to tape accuracy is normally a product of the edit software/edit hardware interface deck control plugin. I use to have all sorts of problems with Adobe Premiere and its interpretation of 'accuracy' and would never use its built in rs422 control always opting for the plugin that came with the hardware; in my case the Blackmagic deck control.

But if you are going the black reference thing just make sure it is feeding both the Axio reference input and the decks reference input. As a test, after you set the deck to 'reference input' as its sync source, playback your timeline and remove the reference to the Axio and you should see the signal thru the deck go unlocked vertically (you may have to do it a few times before you notice the error). This will confirm that the reference signal is indeed doing its job.

Baz

What would I do without the 'UNDO' button!!!!


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Oli da Costa
Re: House sync...genlock...what the?
on Oct 6, 2009 at 2:48:37 pm

Hi Baz, thanks for your post.

I too have always managed to do frame accurate edits without ref signals, both from FCP and Axio, so it was as much my inexperience with this particular VTR as much as anything that flummoxed me!

I had already downloaded the 2000P manual and found and set up all the relevant settings for SDI signal sync-ing as opposed to external sync, so I can only presume that it was a Premiere/422 issue (sadly Axio still uses Premiere's in-built 422 dev ctrl) compounded by not having an external sync.

In the end, I managed to get everything laid off and frame accurate and a GEN10 is now on my shopping list...well for whenever I next need to lay-off, which will be sometime yet...

Thanks again!

Oli da Costa
Fraktiv Post Production
London W1


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Bob Zelin
Re: House sync...genlock...what the?
on Oct 4, 2009 at 1:18:10 pm

On the HDW-2000P from this manual
http://www.rentsoho.tv/2009/equ/vtr/hdw-m-2000-s.pdf

2. Blink of the STOP button
The button blinks when the reference signal is not locked
to an input video signal.
(This function can be canceled in the setup menu ITEM-105.)
. When the OUT REF is set to “INPUT”:
The STOP button blinks when the signal is not input to
the connector selected by the video input selection.
. When the OUT REF is set to “REF”:
The STOP button blinks in the following either cases.
When no reference signal is input to REF. VIDEO connector.
When the reference video signal (REF.VIDEO input) is
not synchronized with an input video signal selected by
the video input selection.


You don't state the frame rate that you are working with. If you are working at normal 625, you can leave the GEN10 in default state, however if you are working at 23.98, you will need to use tri level sync, and ALSO set the HDW-2000P to accept tri level sync (sometimes refered to as HD reference).

If you have been using Beta VTR's, like Sony UVW-1800 VTR's, I bet you have been getting "Error -093 NON STD REF" blinking on the front panel for a long time.

As for my tone, my first job in 1977 was with a London company called TASCO Sound, which was one of the most abusive companies
I ever worked for.

If you haven't been abused, you haven't worked in the entertainment industry.

Bob Zelin




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Mark Suszko
Re: House sync...genlock...what the?
on Oct 6, 2009 at 1:57:12 pm

[Bob Zelin] "If you haven't been abused, you haven't worked in the entertainment industry.

Bob Zelin"


Bob is always right. Gruff, but right. Another similar phrase he's probably heard akin to this is:

"I've been fired by better people than you!". ;-)


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grinner hester
Re: House sync...genlock...what the?
on Oct 4, 2009 at 6:31:58 pm

lol
I love you, Bob.



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Mike Cohen
Re: House sync...genlock...what the?
on Oct 4, 2009 at 9:30:18 pm

Oli - Bob's tone is one of the best parts of this website. He talks that way because, I believe, he hates seeing people make avoidable mistakes.

Mike Cohen


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Vince Becquiot
Re: House sync...genlock...what the?
on Oct 6, 2009 at 3:24:18 am

I guess you could say Bob is the Sam Woh of AV.

Vince Becquiot

Kaptis Studios
San Francisco - Bay Area


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Oli da Costa
Re: House sync...genlock...what the?
on Oct 6, 2009 at 2:57:29 pm

Hi Mike, that may well be, but it's a pretty insulting attitude to take and trying to justify it by citing examples from the 70's doesn't proved any points or make things any better.

I appreciate Bob's advice, as I did Baz's too, but as a forum for professional, asking professional questions, Bob's response was uncalled for.

In the end, I got my answers thanks to both Bob and Baz, and I appreciate this, but really didn't need the agro!

Oli da Costa
Fraktiv Post Production
London W1


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Bob Zelin
Re: House sync...genlock...what the?
on Oct 7, 2009 at 12:01:40 am

Sorry Oli - I can't yell at my clients, so if I am giving you free ACCURATE advice, I have to find some way of charging you - and this is much cheaper and easier than going to therapy (boy Doc, did I have a bad day today ...............)

bob zelin




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