-
Need help with rendering out footage with fields
I have some D1 footage captured through a BlackMagic Decklink Extreme card with Uncompressed 10 bit NTSC settings. Lower fields are first in the settings.
I’m keying out people on green screen and putting graphics behind them.
After I run the footage through after effects and put it back into Final Cut, I can now see some fields in my preview monitor (just on the people – not in the graphics). I checked to make sure my AE project is the same size, aspect ratio etc. The AE footage (people) does not look as clean as the original footage on my monitor. My graphics look very clean , it’s just in the footage.I’ve tried different render settings but not getting a great result.
I’ve tried rendering out lower fields first, setting fields through “Interpret footage” etc.
Some settings make the image clean, but there’s massive field movement showing up when the people move their arms around – or – Some settings give me smooth movement, but the people look kind of interlaced.Is there a certain setting I’m missing that I need to be using when rendering out footage in AE? Or maybe a basic setting formula to try that has worked for others?
Thanks for any help.
Kevin
-
8 Replies
-
If your footage is lower field first…you’ll need to double check after you import it into AE to make sure that it is being interpreted properly . In most cases, when you click on the clip in the project bin, next to the thumbnail there will be information about the clip…name, pixel aspect and lower/upper field. If not interpret the footage to tell AE what it is…lower field first. Then after doing your comp, render out of AE using the same field order (lower field).
In some cases, like with the Avid NLE’s you need to tell it on import what field order, pixel and color (rgb or 601) the footage is.Erik
-
Sometimes enabling ‘Preserve Edges’ in the Interpret Footage dialog can help the look of the footage in AE as well.
Darby Edelen
DVD Menu Artist
Left Coast Digital
Aptos, CA -
Thanks for the tips.
My footage is coming in with no field preference .
When I Interpret the footage AND render out with lower fields picked in the “make Movie” preference area, the footage looks super fuzzy and messed up. If I use one or the other, the footage comes out differently with each setting like:
– Interpret footage – smooth movement on monitor, but you can see some interlacing.
– Don’t interpret footage, but set the lower fields when I render out in the movie preference area in AE – Super smooth good looking footage, but when the people swing their arms or anything it looks very jumpy – like you can see the 2 fields at once –
All of this being previewed on my NTSC monitor – the original footage looks great on this monitor.
Kevin
-
I can’t be sure, but is there any possibility that this footage wasn’t shot interlaced?
Here’s the skinny:
When you set the first field in the Interpret Footage dialog you are giving AE the info it needs to de-interlace the footage (other options include Preserve Edges, which can result in better de-interlacing in some cases, and remove pulldown, which is a topic unto itself).
When you set field render order in the Render Settings dialog you are telling AE to render each frame out as two fields, meaning that if you had a 29.97 frames per second composition you will end up wih 59.94 fields per second.
If you’re at all worried about whether or not your footage should be interlaced or progressive on output, you should probably err to progressive.
If you’re not sure what your source footage should be interpreted as (AE usually does a fairly good job of this on its own) you can try opening the footage in QT Player and look at the video info.
Darby Edelen
DVD Menu Artist
Left Coast Digital
Aptos, CA -
You mentioned earlier that this was captured with a decklink using lower fields…maybe the source was actually upper field first?
As a test, you might capture a little bit of the video using upper field first. Then import into AE (interpret upper) and render it out using upper fields.Erik
-
when i capture with decklink, for some reason ae never interprets field order… not sure why… so you’ll need to set interpret footage manually to separate fields.
a few general rules for field interpretation and rendering…
if you don’t separate fields, don’t render with fields (if ae didn’t remove the fields then they are there, you don’t need to put them back… if you try to it will screw your fields up).
if you separate fields, then you can render with fields, or not… usually if it is going back into an nle to get edited with other interlaced footage, i try to get the fields back. if you want to render de-interlaced, you might also want to turn on preserve edges, the edges usually look a little smoother.
if you are only color adjusting footage, you won’t have to separate fields if you don’t want to, just follow the don’t separate fields workflow above.
if you want to do just about anything else (like keying) then you should separate fields, and use the separate fields workflow above.
by separtating your fields of your keyed footage, then adding motion graphics to your footage, you will be able to render them as either progressive or interlaced, and they will have the same appearance.
Kevin Camp
Designer – KCPQ, KMYQ & KRCW -
you can test the footage you have by setting ae to interpret footage as either dominance, then create a comp that is double the frame rate of the footage. find a section that has some movement and step trhu it frame by frame.
if the movements appears to step forward, then backward as you advance thru the frames, then your dominance is reversed. change the interpretation to separate the other field first, and recheck the movement.
Kevin Camp
Designer – KCPQ, KMYQ & KRCW -
A question Kevin, I honestly don’t know the answer:
If the footage on the tape is upper field first, and you capture it as lower field first, what sort of problems will this cause?
Darby Edelen
DVD Menu Artist
Left Coast Digital
Aptos, CA
Reply to this Discussion! Login or Sign Up