-
Text dirty edge problem
I have a simple AE comp element where I float a text word up from center screen (on the Z-axis) and then it eventually zooms forward directly into the camera– so the white of the text fills the screen and I then transition to the client’s white logo screen. With motion blur, the simple effect works great. The trouble I’m having though is that on the versions with lighter backgrounds, I am seeing some black edging, almost a vertical jitter of some sort behind the letters of the text as it slowly moves forward. Almost as if the alpha channel is not clean, and I am seeing some edges of black, as if from a high contrast matte. I really only notice the problem on the lighter backgrounds.
When I render out the comps and import, I have been using these settings:
Render at Best Quality
Animation codec
Field rendering off
RGB+Alpha
Straight alpha, unmatted
The comp is 720×540, but I just have AE crop the top and bottom to make the final render 720×486
(not worried about the reshaping of the text)Importing into Avid Media Composer 9000XL, 601 non-square, non-interlaced, inverting existing alpha
Any idea what could be causing the dirty edges? They seem to wobble a bit… I tried field rendering but the zoom up then gets funky.
** Also, I have gotten files from graphic artists in the past where their text sits on a background that matches the text color. Is this related to using Premultiply for the alpha rather than Straight?
Thanks!!
-Mike
-
2 Replies
-
It sounds like you are rendering this as a keyable element. If you are, you should choose ‘straight’ in your output module render settings.
by choosing RGB+Alpha for the channels, your graphic will be matted. So choosing straight for the color, will make the fill video compensate for the softness of your alpha channel. That way the keyed logo will not pick up black or the background color on the edges.
hope this answers your question.
charlie -
Hi Charlie,
Thanks for responding, but I am already rendering out the comps with RGB + Alpha, and color as “Straight”. The problem is more evident with small text in motion on the Z-axis against light backgrounds. As the text moves foward slowly, the edges of the text and its alpha channel seem to wobble a bit… small text is not as clean as when the text is larger. I realize it’s difficult to diagnose without actually seeing a sample…
Thanks!
-Mike
Reply to this Discussion! Login or Sign Up