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little interesting test with HDV and ioHD Prores

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Carsten Orlt
little interesting test with HDV and ioHD Prores
on Apr 14, 2008 at 10:55:59 pm

FYI :
We just bought a little Canon HV30 as a 2nd unit 'get into that small corner/crash' camera.
It records 1080psf25 (PAL version) onto tape in HDV.

I captured the footage 2 different ways: Through firewire using the Apple HDV to Prores preset and via HDMI into the ioHD using the ioHD 1080i25 preset. Both non (HQ) as I'm not seeing the benefits for my work in capturing (HQ). The Apple HDV to Prores produces a 1440x1080 frame size and the HDMI to ioHD produces a full raster 1920x1080 frame size. Side by side put into a ioHD Prores 1080i25 1920x1080 timeline and rendering the 1440x1080 clip (to get it to full raster) you basically don't see a difference.

BUT if you send this to Color 2 things are happening: The coding of the 2 clips is different as you can't use the same grade on both clips to get the same result. Grading the 1920x1080 clip and then applying this grade to the 1440x1080 clip gives a very different result. Much more contrasty is the best I can describe it. I'm no technician but could it be different gamma handling?
The second thing that is happening is that the size change that Color correctly applies to the 1440x1080 clip produces a worse render result then the FCP render.

So after sending the Color timeline back to FCP you now see a difference in the clips and the result is better with the ioHD full raster 1920x1080 clip. I wouldn't say far better and you probably wouldn't notice without the comparison but side by side the ioHD encoding wins!

Big problem is of course that without a HDV deck using HDMI from the camera you loose the timecode reference from your tape.

So not every Prores encoding is equal. Lots to learn....

PS if anyone sees a flaw in the test procedure please let me know :-)

Carsten


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Carsten Orlt
should of course read: 'interesting little..' instead of what I wrote
on Apr 15, 2008 at 2:23:55 am

:-)


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George Griswold
Re: little interesting test with HDV and ioHD Prores
on Apr 15, 2008 at 9:25:01 am

I don't have my ioHD system yet so I am really going out on a limb... I think I read somewhere that you can use the firewire link to access TC and another path for the video/ audio signal independently.
As for your grammatical correction--- at least it wasn't in a title running full screen in a video program after a client asked for a correction.
Cheers,
George

George Griswold
http://www.videonow.info
New Orleans, Louisiana


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Carsten Orlt
Re: little interesting test with HDV and ioHD Prores
on Apr 15, 2008 at 9:37:28 am

That's why I 'normally' read my credits a million time :-) (being one of those non-native people)

As for the firewire plus ioHD option: I work on a MacBook Pro and tried to control the camera via firewire and capture HDMI to the ioHD at the same time. Didn't work. Maybe it does if you have a separate firewire card in a desktop system?

Cheers

Carsten


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George Griswold
Re: little interesting test with HDV and ioHD Prores
on Apr 15, 2008 at 10:56:18 am

Nothing can share the Firewire bus with the Aja ioHD. From what I gather adding a FW card in a Mac Pro will work- I will let you know in a few weeks. I am planning on capturing HDV via component and controlling via FW which should get around the HDV long GOP problems. All speculation right now until I get my system.

George Griswold
http://www.videonow.info
New Orleans, Louisiana


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Carsten Orlt
Re: little interesting test with HDV and ioHD Prores
on Apr 15, 2008 at 12:01:50 pm

Thanks George!

Carsten


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