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-   -   720p for broadcast? (https://www.dvinfo.net/forum/jvc-gy-hd-series-camera-systems/68575-720p-broadcast.html)

Stephan Ahonen June 1st, 2006 09:05 PM

Quote:

Originally Posted by Bob Diesso
Unless I'm mistaken, material recorded at 24P or 30P is played out at a 60P cadence. Similar to the way in which film shot at 24 frames per second is viewed on broadcast television. Others here may be better equipped with technical detail.

That's correct, it's pulled down exactly the way that it's pulled down for SD, only you're pulling down over frames instead of fields.

Quote:

Originally Posted by Jemore Santos
So the HD100 is using 30p in a 60p wrapper with pulldown?

That is correct as well, the HDV spec allows for a "repeat frame" flag so that the duplicate frames don't take up any space.

Jemore Santos June 2nd, 2006 03:38 AM

So hyperthetically the 24p on a HD100 should be similiar to the new models, HD200/250.

Paolo Ciccone June 2nd, 2006 09:12 AM

Quote:

Originally Posted by Jemore Santos
So hyperthetically the 24p on a HD100 should be similiar to the new models, HD200/250.

Actually I believe that they are identical. In fact the new mode, 60p, uses the same transport and very similar encoding, it just changes the length of the GOP from 6 to 12.

Steve Benner June 2nd, 2006 09:22 AM

Quote:

Originally Posted by Paolo Ciccone
Actually I believe that they are identical. In fact the new mode, 60p, uses the same transport and very similar encoding, it just changes the length of the GOP from 6 to 12.

I would be cool if JVC offers a offer to send in the HD100 so that they can upgrade the software to allow for 60P and the other upgrade features. I would pay between $1000-2000 for that if it is possible.

Joe Carney June 2nd, 2006 12:46 PM

Quote:

Originally Posted by Steve Benner
I would be cool if JVC offers a offer to send in the HD100 so that they can upgrade the software to allow for 60P and the other upgrade features. I would pay between $1000-2000 for that if it is possible.

Me three, but I thinks it's new hardware and software. But if they offered it, I would find a way to pay 1 to 2k if it's possible.

Steve Mullen June 2nd, 2006 02:24 PM

Quote:

Originally Posted by Paolo Ciccone
Actually I believe that they are identical. In fact the new mode, 60p, uses the same transport and very similar encoding, it just changes the length of the GOP from 6 to 12.

I asked JVC about GOP length and they said only 50P/60P will get 12 frames. So there will be no change to 24P, 25P, and 30P.

By the way, I'm happily using Avid Liquid 7.1 with 24P.

Paolo Ciccone June 2nd, 2006 03:18 PM

Quote:

Originally Posted by Steve Mullen
I asked JVC about GOP length and they said only 50P/60P will get 12 frames. So there will be no change to 24P, 25P, and 30P.

My bad, I wasn't clear. That's exactly what I meant, only the new modes get different GOP.

Keith Winstein June 3rd, 2006 06:50 PM

Quote:

Originally Posted by Tim Dashwood
Lost or Desperate Housewives are both shot 24fps on 35mm film. They are transferred at 23.98P to HD masters, then the stream is broadcast on ABC in 720P60, but it is 24P in a 2:3 pulldown - exactly the way the HD100 handles 24P.

Hi Tim,

This is just a side note, but in my experience, ABC actually sends 60 discrete frames per second in a 720p60 MPEG 2 sequence. The "3:2 pulldown" happens before the material is transmitted -- perhaps even before it's edited. (Some film-source network programs do not seem to respect the original film frames in their cuts.)

By contrast, the HD100 actually sends only 24 discrete frames per second and uses the MPEG-2 flags in order to instruct the decoder on how to perform the 3:2 pulldown to produce 60 frames per second.

Stephen L. Noe June 3rd, 2006 07:17 PM

Quote:

Originally Posted by Steve Mullen
By the way, I'm happily using Avid Liquid 7.1 with 24P.

Glad to see you're back in the fold....

Taylor Wigton June 4th, 2006 09:10 PM

No JVC for B-Cam
 
Quote:

Originally Posted by Tim Dashwood
Rodney is using a HD100 as a B-Cam for a film he started shooting this week in Toronto on Panavision's Genesis. When I consulted with him the goal was to match the Genesis fairly closely as far as black stretch and knee (even though the Genesis has WAY more latitude.) I think Rodney decided on Black stretch 2 and a 80% knee, but I report back when I find out how his shoot went.


You can read more about Rodney's tests on the Showreel magazine website.
http://www.showreel.org/memberarea/article.php?141

There are two Genesis's on the set Rodney is shooting, so both A & B cameras are Panavision. The HD100 is not shooting on set up in Toronto, but it did go through a series of tests before the production commenced, using the expensive HD Fujinon lens that JVC also sells for use with the HD100. ($10k for that lens???)

Jonathan Ames might have is own thoughts on the subject as he looked at the footage as well, but in looking at the test footage at the lab in Toronto, the JVC stood its ground in some respects but the blacks were milky and the resolution was not even close to the Genesis. I did not know until friday that the menu settings has been changed from thier previous settings so therefore can not make a good assessment about what the footage would have looked like had the menu been left alone. FWIW.

Taylor Wigton
DP, Los Angeles

Jonathan Ames June 5th, 2006 06:46 PM

Actually, my only comment would be to say that, whether it's an expensive pic like Molly or an independent like most people here do, collaboration is the ticket to success. The results that happen when you combine a camera as great as the Genesis with the experience and God-given ability of a wonderful person and DP you have in Rodney and the job Eyes, the boutique post house Rodney chose in Toronto did in daVinci are truly spectacular and I appreciate the opportunty to have seen them while in Canada. But the down side is the limitations it showed in the JVC. The 100 HD is, again, a great camera for what it is and the more we know about it through the advice of knowledgable people here on the board like Tim and Chris and Paolo and others and the more we understand about digital cameras in general through writings like Steve Mullen, the better the results of our own use will be. In a shamelss plug, that's exactly why we're spending the money we are to produce the 2nd Unit web site which I promise is going to debut on June 20th. By producing the first 13 weeks of hour-long webcasts, ironically shot on JVC 100HDs, in which various ASC cinematographers and other professionals discuss the numerous aspects of cinematography, we're hoping to provide everyone here with a chance to hear from the pros and then bring that information back to these boards for further, in-depth discussion. George Dibie, Rob Kositchek and Rodney have all agreed to guest spots and we'll have the other 10 hopefully signed over the next couple of weeks.


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