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Cees van Kempen January 20th, 2012 08:14 AM

Specific advise on codec and bit rate
 
With my nanoflash I ususally shoot I-Frame Only @ 220 mbps. I prefer I-Frame above LongGop for my workflow. Shortly I will be on an expedition with no access to mains and I will dump my footage on Nexto devices. I want to keep data rate lower during this trip and consider two options:

- Shoot LongGop @ 50mbps and transcode to Prores in post
- Shoot I-Frame @ 100mbps and work with this files in post

I understood well that quality of LongGop @50 should be better than I-Frame @100, but am not sure if that will still be the case when transcoded to Prores afterwards.

Does anyone have advise on which will give the best end result quality wise?

Andy Mangrum January 20th, 2012 09:55 AM

Re: Specific advise on codec and bit rate
 
Hello Cees,

What NLE are you using to edit your footage?

Best Regards

Dan Keaton January 20th, 2012 03:07 PM

Re: Specific advise on codec and bit rate
 
Dear Cees,

Personally, I never recommend 100 Mbps I-Frame Only.

I would shoot 50 Mbps Long-GOP over 100 Mbps I-Frame Only.

140 Mbps I-Frame Only is ok to use.

100 Mbps I-Frame Only should be reserved for very unusual situations.

Dave Sperling January 21st, 2012 10:56 AM

Re: Specific advise on codec and bit rate
 
My feeling is that if you have enough cards, go with 100Mbps Long-GOP. The picture will be that much better, and then Xfer to pro-res if you need to. Start with the best image you can afford! The nano at 100/LongGOP is excellent!

Ronan Fournier January 21st, 2012 11:10 AM

Re: Specific advise on codec and bit rate
 
If you are on expedition with a limited space on the Nexto, 100Mb/s maybe be risky. 50Mb/s is good (approved for broadcasting by BBC) but you may think that you haven't the best possible quality for your project. So the good compromise seems to be Long-Gop 80Mb/s! :)

You may also adapt the data rate during the shooting: 50Mb/s for interview, 100Mb/ for complex shots in nature with a lot of movements for instance…

Cees van Kempen January 23rd, 2012 02:39 AM

Re: Specific advise on codec and bit rate
 
Thanks all. It seems 50-100 mbps LongGop is the way to.

Andy, I use Final Cut Pro 6.

Cees

Dan Keaton January 23rd, 2012 07:12 AM

Re: Specific advise on codec and bit rate
 
Dear Cees,

For Final Cut Pro, for you situation, 50 to 100 Mbps Long-GOP should work great.

If you have scenes with an excessive amount of detail, or excessive movement, then 100 Mbps is preferred.

If you were editing it older versions of Avid, then 50 Mbps Long-GOP would be preferred.

Andy Mangrum January 23rd, 2012 11:35 AM

Re: Specific advise on codec and bit rate
 
Hello Cees,

Any Bit rate would work fine for Final Cut Pro,

Everyone has mentioned very good advice,

Thanks Everyone,

Best Regards

Adam Letch January 23rd, 2012 05:37 PM

Re: Specific advise on codec and bit rate
 
I'd go the 80mbps long GOP, noticed a worthy jump in quality from 50, and you save space over 100. But at the end of the day, the size of your field back up will determine everything..

Ron Little February 2nd, 2012 10:05 AM

Re: Specific advise on codec and bit rate
 
I just finished a music video shot on green screen. I went with 50mbps long gop. Would 80 mbps be better for green screen?

Dan Keaton February 2nd, 2012 12:14 PM

Re: Specific advise on codec and bit rate
 
Dear Ron,

50 Mbps Long-Gop may work fine for you, for green screen work.

I would normally recommend 100 Mbps Long-GOP, unless one is editing in older versions of Avid.

Ron Little February 3rd, 2012 10:07 AM

Re: Specific advise on codec and bit rate
 
Thanks Dan. I have another green screen job coming up. I will give the 100mbps setting a try. I guess I should test it with CS5 before the job just to make sure I can edit it.

Dan Keaton February 3rd, 2012 10:14 AM

Re: Specific advise on codec and bit rate
 
Dear Ron,

That is always a good idea.

Ron Little February 26th, 2012 08:54 AM

Re: Specific advise on codec and bit rate
 
Dan, I just wanted to check back in to let you know that the green screen shoot at 100mbps went well. It was the easiest key I have ever pulled. It is 100mbps from now on.

The Nanoflash is a great product but your service is above and beyond.
Thanks Ron Little

Dan Keaton February 26th, 2012 09:24 AM

Re: Specific advise on codec and bit rate
 
Dear Ron,

Thank you very much for your kind comments.

We try hard to provide world-class service 24/7.


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