AE, thin line at edge of picture
 

I built a simple lower thirds composition in AE CS5. It consists of a couple of long thin boxes (gradients that ramp up and back down) done in Photoshop; I add text to the more opaque parts in AE. It uses a simple linear motion -- from off screen to the left, it slides right onto the screen, holds a few seconds, then slides back off to the left again. Nice and simple.

All works fine. But... (and there's always a "but" isn't there?) I notice in looking at the final product (on a big TV) that there is to be a very thin line at the picture boarder (left side) that the composition doesn't overlay. That is, it's a thin line of the background picture. Maybe just a pixel or two. Hard to say, but a very thin line.

This is there the whole time. When I step through the motion one frame at a time it's evident during the entire motion. When the lower third slides onto the picture it's like this thin line of the picture is on top of the composition. Except, it's not on top. The picture is on the bottom as it should be. Hmmm (sound of scratching of head)...

What causes this? And what can I do to get rid of it?

I'd post an image, but I can't figure out how to get access to AE's snapshots. How does one extract an image from the AE composition viewer so one can post it here?

Re: AE, thin line at edge of picture
 

Check the position numbers to make sure you didn't bump the lower thirds layer along the x axis. It's pretty easy to make that mistake.
I've hit the arrow keys by accident which move whatever is selected. A couple of pixels is hard to see until you get in on a big screen. :)

Re: AE, thin line at edge of picture
 

The composition starts fully off screen to the left. It then slides to the right along the X-axis until it's almost but not quite fully on screen, then it goes back where it came from. And it doesn't matter where the graphic is -- if any part of the graphic is on screen, that line is visible.

Re: AE, thin line at edge of picture
 

Hi Bruce. To get a snapshot from AE make sure your comp is selected then Compostion/Save Frame As/File and you then save out of the Render Queue, set your destination and then change from "Photoshop" in the Output Module to get the format you want (it will say 'Sequence' but don't worry about it, it will only save the one frame). As Robert suggests it sounds like the lower third layer has been nudged along a bit - in After Effects use the left arrow key to nudge it back 1 pixel at a time if that is the case.

Re: AE, thin line at edge of picture
 

If it is an issue within the AE composition....

Nest the comp, throw a mask on the edge, and re-render.

And to get pictures from AE, just take screenshots.

Re: AE, thin line at edge of picture
 

OK, here's a file showing the problem. I rendered out a frame from the vid as Mr. Gesch suggested in message #4 above (thanks for that -- I would have spent hours trying to figure that out without your help). Then I cropped it down to just the lower left corner because the rest is distracting and to make it a quick download for anyone who wants to see it.

In the file the lower third composition (the green / blue horizontal bars) is in motion, moving from off the frame (left) into the frame. The problem persists whenever any part of the lower third comp. is in the frame at all. IOW, it's not motion dependent. And I did check, a bit of the lower third composition stays outside the frame at the end of motion, so it should be "full bleed" as they say in the printing world.

The problem is that one pixel gray vertical line on the edge of the picture.

Anyone know what's causing that?

Re: AE, thin line at edge of picture
 

One more try to upload that file.

Easiest way to see it is download the file, then open it in Photoshop and enlarge it. The line is clearly visible -- once you enlarge it enough to see it. A one pixel line is pretty small. ;-)

Re: AE, thin line at edge of picture
 

Sorry Bruce but the image can't be accessed for download. ??

Re: AE, thin line at edge of picture
 

Hmmm.... it lets me download it. Just a right click on the image to get a popup list, then a "save image as" to my desktop works.

This is my first image upload to this forum so I've got very little experience on how this forum handles such a download. Hmmm....

Let's see if I can upload an enlargement then. The problem is that one pixel vertical line of background (gray) on the left hand side. This image is just a small chunk out of a 1920 x 1080 frame, and the AE composition is about half on and half off the screen, moving from left to right.

Re: AE, thin line at edge of picture
 

Hi Bruce, thanks for enlarging the image (I was expecting when I clicked the original image to be taken to another page - my apologies I was just having a 'brain fart').
I'm unclear about exactly how you have things organised:
Are the lower thirds precomps which are being added into your major comp?
if so, is the animation in your precomp - or are you animating the whole precomp in and out in your major comp?
If the animation is in your precomp do you have the edge problem there?

Re: AE, thin line at edge of picture
 

Yes.

Animation is in precomp.

Yes.

But... it's perhaps a moot point now. I duplicated the pre-comp in question and used the copy somewhere else in the same composition. This copy didn't have the problem. I don't know why. So I made a copy of the copy and changed the text to match the original (I did *not* change the positions or key frames in any way). Placed it in the layer right above the problem pre-comp so I could turn them on and off while I scrubbed the vid back and forth. They are identical in all respects except that the original has this gray vertical line, and the copy does not. So I trashed the original. Problem solved, at least for today.

But I would like to know what the heck was going on there. Freaky. No doubt it will rear its ugly head again sometime in the future.