View Full Version : 1080 with GY HD251


Wade John
June 29th, 2008, 06:49 AM
I have recently bought a 251 and i'm afraid i'm pretty clueless. The manual is pretty unhelpful, especially since this is my first HD camera. I've ordered Tim's DVD and looking forward to getting it but in the meantime hopefully you can answer these basic questions.

* I want to record 1080 with it - from what i can work out, 1080 only outputs this through the SDI output. what will i need to record this onto?

* I've searched this forum and heard some talk of uprezzing? what does this involve to get 720p up to 1080i? I use adobe cs3.

Sorry if these questions are really basic but i've searched around and cant seem to find any clear answers.

Carlos Rodriguez
June 29th, 2008, 12:54 PM
I think only the newer HD200 units output 1080 through firewire and into a hard drive. Otherwise you could record out from HD-SDI on the 251 into a recorder with an HD-SDI input. This would probably get you a cumbersome file unless you capture as an intermediate into something like FCP.

I found this article on adobe's site.

http://livedocs.adobe.com/en_US/PremierePro/3.0/help.html?content=WS900278C5-C826-45dd-97B5-2AC27D6CC3CB.html

I think even cineform has a device that has HD-SDI in.

Wade John
July 3rd, 2008, 06:56 PM
Am I right in understanding that this machine does not output true 1080i, but an uprezzed signal through the HD-SDI? In that case, how does the quality differ from a camera with true 1080 specs? What if I record the footage on a quality device such as the convergent Flash XDR?

Jason McCormy
July 4th, 2008, 01:46 PM
Wade, that is an interesting question, is it just up converted 1080? Also, I'm curious if it can record 720 60 to the tape while simultaneously record 1080i to a harddrive through firewire?

Tim Dashwood
July 4th, 2008, 03:07 PM
JVC has never really come out and said how they achieve 1080i. I don't have a HD200B or I could compare with 720p against a resolution chart and see if there is any benefit/disadvantage in resolving power. I think my dealer has a rental version in the inventory now so I'll put it on my to-do list.

The Flash XDR gives you the advantage of skipping low-bitrate 4:2:0 long-GOP encoding in the camera and pumping it up to 160mbps 4:2:2 without GOPs.

The tape transport is completely disabled when a HD200 or HD250 is in 1080i mode so there is no possibility of 720p60 simultaneous recording.

Jason McCormy
July 4th, 2008, 07:10 PM
Tim,

Thank you for the response. I am a total newbie though, and wonder what the Flah HDR is and if the 4:2:2 is with 720 or 1080? Also, what is a GOP?

Also, are the none tape recorders reliable enough for production?


Thank you for your help!

Wade John
July 5th, 2008, 05:20 PM
Thanks for your replies. Jason, I'm very much a newbie myself but I can tell you that the Flash XDR is made by Convergent Design. It looks a very nice piece of equipment where you can record out of the HD-SDI port onto four compact flash cards at a high bitrate. Unfortunately, its a bit out of my price range at the moment. However, if the 1080i is a big improvement over the 720p, I might be able to break the bank. That's why I'm asking these questions because I'm very interested to know whether the 1080i is worth bothering with on the GY-HD251.

GOP stands for 'group of pictures'. Here is a wiki article:
http://en.wikipedia.org/wiki/Group_of_pictures
There's more to it than that, but it gives you a start.