AE CS3 - Interlace Flicker and Alpha Channel
by Luis Segovia
on
Feb 14, 2008 at 11:00:11 pm
Hey, I jusy staring with AE and I need a lot of hellp.
I need to make an animation and then use it in Final Cut Pro, in this animation I'll use some files that come from Photoshop, but I have tons of problems.
1 - I would like to know if there is any kind of tutorial that teach how to elimitae the Flickering in AE, I try adding one adjustment Layer and appling to this a effect called reduce interlace flicker, but the video looks the same bad.
2 -I know that Photoshop have a filter that could made the same, Do I need to add the filter in Photoshop or can I do it when the layer is in AE?
3 - I want to add an alpha channel to the animation, but I need the video in Quicktime, so, I went to render queue, then output module, then on format I choose Quicktime Movie, but the option to add the RGB+Alpha is unavailable, what can i do?
4- Any one knows if there is any book or tutorial that teach all this things?
Re: AE CS3 - Interlace Flicker and Alpha Channel by Luis Segovia on Feb 15, 2008 at 2:57:22 pm
Hey, thank you for taking the time to answer me, and the answers are, I'm using a stock footage for background, I'm not sure if is interlaced, but looks nice on the TV screen, the only thing that looks jumping when is moving is the graphic I made in AE, and when the graphic stops looks better and yes, I'm rendering interlace and yes, some of the graphics have thin lines.
thank you again
Re: AE CS3 - Interlace Flicker and Alpha Channel by Steve Roberts on Feb 15, 2008 at 3:36:00 pm
Stock footage is usually film shot at 24fps then telecine'd to run at 29.97 fps for NTSC or 25 fps for PAL. If you intend to leave the footage alone (no moving, blurring, rotating, scaling or distorting) you can leave it that way. If NTSC, the footage will have some interlacing. The way to tell if footage is interlaced is to interpret it with field separation "off", then double-click on it to view it and look for the interlacing.
If you want to move/scale/blur/rotate/distort the footage, you have to separate fields if the footage is interlaced, and you have to remove pulldown if the footage came from film and you're in NTSC. Check the Help if you don't know about pulldown. To confirm that you've removed the pulldown correctly, alt-double-click on the interpreted footage and step through it with the pageDn key. You should see no interlacing. If you see interlacing, remove pulldown using a different WWWSS (etc.) cadence.
Your graphic may be jumping if you chose the wrong field order (not "field dominance", by the way) when rendering: upper field first or lower field first. Try the other one.
If the fine lines in your photo are flickering, apply a slight directional blur (vertical, or both horizontal/vertical if necessary) to the image, maybe 1 pixel if the image is scaled at 100%. If you shrunk the image, use a large value: 2 pixels if the image was scaled 50%, 4 if it was scaled 25%, and so on. The goal is to get a blur of 1 pixel as seen in the comp, so the thin lines soften a bit as to not conflict with the interlacing.
Re: AE CS3 - Interlace Flicker and Alpha Channel by Luis Segovia on Feb 15, 2008 at 4:34:55 pm
Hey, thank you, I used the Animation codec and the alpha channel is working now, I'm going to work with the flicker problem, make some testing and see what happend, I'll let you know if I'm able to have some progress, also do you know if the book After Effects in Production deals with issues like this?
thank you
Re: AE CS3 - Interlace Flicker and Alpha Channel by Steve Roberts on Feb 15, 2008 at 4:41:38 pm
[Luis Segovia]"...do you know if the book After Effects in Production deals with issues like this?"
I'm not at the office, so I can't check the book there. If you like, you could write Trish Meyer at cybmotion.com and ask which book covers it ... but they are rather busy, so I don't know if I'd ask them to solve the problem through e-mail. :-)
I recommend you get all three books (CMG 1,2 and AEinProd) because you'll refer to all of them at one time or another.
