lines appearing on After Effects clips
 

Hello,
I'm a new user of AE and I'm having problems with clips that I edit in this program. Basically when I import video clips into AE short thin lines appear on some of the clips. Usually it's just one or 2 small lines and generally concentrated on the same area of the screen for all the clips.

These lines are more obvious when I use filters like the keying filters. I've tried playing around with the fields for the clips but it doesn't make a difference. The clips don't have the lines when played from the hard drive or in Premiere, only when I bring them into After Effects. I use AE 5.5 and 6.0 and the problem is in both of them.

This is getting really frustrating for me because I can't think of what could be causing this and these lines can be quite obvious on the tv monitor.

I've also noticed that they appear more on clips that have movement i.e either the camera or the subject moving.

Any ideas on what the problem could be?
Thanks

First of all AE isn't for editing, really (just so you know). Second,
please tell us what camera the footage originated on and what
settings you used to record the footage.

My guess would be interlacing artifacts. Especially since they
appear with movement (this happens a lot with interlacing when
watching it on a computer monitor). You should not see this on
a TV (unless it is a broadcast monitor then it might) unless you
have reversed the interlacing order. Keep in mind that DV is
lower field first. I would not be suprised if you have set AE to
upper field first (analog default).

Hi Rob,
thanks for your reply.
The footage was captured from a Sony PD150 and I'm not sure what settings were used because I didn't do the camera work. I've had this problem also which just animated graphics.

I use a matrox RT2500 capture card and the interlacing order is set to upper fields in Premiere by default (I assume from the card). The footage is fine there. But when I take it into AE these artifacts appear on the footage and then they appear in Premiere when I take the footage back. They also appear on my TV monitor (not a broadcast one).

I've played around with the interlacing order but it doesn't make a difference. I know how the lines look when the fields are reversed and they are different from the lines I am getting now. These lines I'm concerned about are usually just one or two short streaks and always in the same area on the clips.

It would be handy if you can put up a picture of this effect on a
site somewhere. What is the field setting in AE? Does it always
do it with a certain effect or with a certain type of footage? The
best thing to do is to try and zero in on the problem and if you
can repeat it or not (so if it happens in a project, make a new one
where you do the exact same thing. See if it happens again and
at the same spot etc.).