Compositing with Z1U Footage at DVinfo.net

James Huenergardt · April 16th, 2006, 09:23 AM

Hi,

I'm working on a project in which I've shot some 1080i 60 (or however you put it) footage on my Z1U.

I am now in the process of creating a 3D background in Lightwave, but am wondering what size to make my 3D images?

I tried 1440 x 1080 with the 1.33 aspect ratio, but when i bring them into After Effects, they are 'sqare pixels' and narrower than my Z1U footage.

I then tried 1920 x 1080 with 1.33 aspect ratio and that looks squished in After Effects.

If I render 1920 x 1080 sqare pixels, and bring that into my Cineform Comp then it looks fine.

Any thoughts on this? My goal is to produce the entire project in HDV and then output to DVD and Quicktime.

Thanks,

Jim

Matt Davis · April 18th, 2006, 04:28 AM

Quote:

Originally Posted by James Huenergardt

Any thoughts on this?

I still use AfterEffects 6.0, and noticed a little repeatable bug in dealing with HDV - you have to set and unset the 1440x1080 pixel ratio a couple of times (e.g. it comes in as 1440x1080 but is wrong - you switch it to square pixel and it's very wrong, then switch it back to the correct setting and suddenly it's right).

I initially put this down to my senescent version of AE predating HDV, but it may be a deeper QT thing as QT sometimes makes the blanket assumption that everything's square pixels - hence a PAL MPEG2 in QT Player is reported as being 720x540 instead of 720x576, even though the latter is accurate. If QT Player passes this info to AfterEffects, AE takes it in good faith, and so to unset it then reset it allows AE to 'do the right thing' and get the correct aspect ratio.

Alex Raskin · April 18th, 2006, 08:24 AM

I have to say that, before going into the image ratio issue, one should have a workable video source for compositing.

Based on my experience, Sony's HDV (which probably is one of the best in its class) is unpredictable and very hard to use for compositing. The culprit is MPEG2 compression macroblocks.

To address this specific issue, I built the entirely separate HD ingest PC system for uncompressed capture from Sony Z1/FX1's Component out. Sony's Component out is before any mpeg compression, so it's clean enough to use for greenscreen work.

Having said that, it is still possible to do compositing on mpeg-compressed footage, too. I did it, others did it. Just don't expect repeatable and stable results (you know how it goes, problem suddenly occurs when you are under the deadline etc.)

To see my own compositing efforts (using compressed video - I did not have my HD ingest system at the time...) just go to www.PrimeHD.com and click on "read more" under "Prime HD encodes music video for quality web view". I hope this may be of interest on the subject.

Steven Gotz · April 18th, 2006, 08:29 AM

To change the initialization profile in After Effects 6.5 (7.0 already has this) to include a 1.33 pixel aspect ratio, and make native 1440x1080 compositions:

Go into the After Effects 6.5/Support Files/intepretation rules.txt file (also works with 6.0) and add this line to the bottom:
0, 0, 0, "0000", * = 4/3/"Custom Aspect", *, *, *

Export as 1440X1080 and use 1.33 - you will be happier in the long run.

Matt Davis · April 18th, 2006, 02:39 PM

Quote:

Originally Posted by Alex Raskin

...one should have a workable video source for compositing... Sony's HDV (which probably is one of the best in its class) is unpredictable and very hard to use for compositing.

I've found it more forgiving in AfterEffects when pulled down to SD:

http://www.mdma.tv/HDV_chromakey_1.png - Here you see the raw footage with KeyLight applied - clean key, but the 4:2:0 is making it look like it's been cut out with a cheese grater.

http://www.mdma.tv/HDV_chromakey_2.png - Once the comp is shrunk down to SD, it's a lot happier and cleaner. Note the transparency on the RH arm. The grab is done at 1:1 so what you see is what you get - a lot cleaner and (crucially) a lot sharper than a DV chromakey, even with the best filters on the market (KeyLight, zMatte, DVmattePro).

Based on this, and the budget my clients can afford, I find HDV is the best way for me to shoot chromakey - it's better than DV, and it just would not happen if I had to go digiBeta.

Just for fun, here's the web version of the finished movie - the wierd arch thing was the hole it was projected into - it was about 15' high!

http://www.mdma.tv/movies/HDV_chromakey_3.mov - it's a bit of fun from the client, a VP of a huge company who was game for a laugh. Most definately NOT a pop video. :-)

Please don't trash HDV for chromakey at SD. It does work, repeatably.

April 16th, 2006, 09:23 AM	#1
James Huenergardt Major Player Join Date: Nov 2005 Location: Chehalis, WA Posts: 513	Compositing with Z1U Footage Hi, I'm working on a project in which I've shot some 1080i 60 (or however you put it) footage on my Z1U. I am now in the process of creating a 3D background in Lightwave, but am wondering what size to make my 3D images? I tried 1440 x 1080 with the 1.33 aspect ratio, but when i bring them into After Effects, they are 'sqare pixels' and narrower than my Z1U footage. I then tried 1920 x 1080 with 1.33 aspect ratio and that looks squished in After Effects. If I render 1920 x 1080 sqare pixels, and bring that into my Cineform Comp then it looks fine. Any thoughts on this? My goal is to produce the entire project in HDV and then output to DVD and Quicktime. Thanks, Jim

April 18th, 2006, 08:29 AM	#4
Steven Gotz Trustee Join Date: May 2002 Location: Clermont, FL Posts: 1,520	To change the initialization profile in After Effects 6.5 (7.0 already has this) to include a 1.33 pixel aspect ratio, and make native 1440x1080 compositions: Go into the After Effects 6.5/Support Files/intepretation rules.txt file (also works with 6.0) and add this line to the bottom: 0, 0, 0, "0000", * = 4/3/"Custom Aspect", , , * Export as 1440X1080 and use 1.33 - you will be happier in the long run. __________________ Steven Gotz http://www.stevengotz.com

April 18th, 2006, 08:24 AM	#3
Alex Raskin Trustee Join Date: Sep 2003 Posts: 1,435	I have to say that, before going into the image ratio issue, one should have a workable video source for compositing. Based on my experience, Sony's HDV (which probably is one of the best in its class) is unpredictable and very hard to use for compositing. The culprit is MPEG2 compression macroblocks. To address this specific issue, I built the entirely separate HD ingest PC system for uncompressed capture from Sony Z1/FX1's Component out. Sony's Component out is before any mpeg compression, so it's clean enough to use for greenscreen work. Having said that, it is still possible to do compositing on mpeg-compressed footage, too. I did it, others did it. Just don't expect repeatable and stable results (you know how it goes, problem suddenly occurs when you are under the deadline etc.) To see my own compositing efforts (using compressed video - I did not have my HD ingest system at the time...) just go to www.PrimeHD.com and click on "read more" under "Prime HD encodes music video for quality web view". I hope this may be of interest on the subject.