View Full Version : How to get a credit roll without a "shimmer"


William Hohauser
March 1st, 2007, 03:41 PM
I am putting a very long title roll together in After Effects from a Photoshop ducuments. The font is small and I get a one pixel "shimmer" at the tops and bottoms of the letters. The strange thing is that the shimmer has a slow frequency, every 10 frames or so.

Any solution?

Mark Bournes
March 1st, 2007, 03:55 PM
Use the "flicker effect" on it and that should help.

William Hohauser
March 1st, 2007, 10:13 PM
Thanks, will try that.

Tim Dashwood
March 2nd, 2007, 09:44 AM
William,

If it is a 60i sequence there is only one way I know to get around it with small fonts, and still maintain the detail/resolution.
You could create your roll in a 30P sequence and then nest it into your 60i sequence.

William Hohauser
March 2nd, 2007, 11:00 PM
Indeed, it's 60i.

I should take the AE project and switch it to 30p NTSC and make a movie?

Tim Dashwood
March 5th, 2007, 10:03 PM
Indeed, it's 60i.

I should take the AE project and switch it to 30p NTSC and make a movie?

Yes. Turn off field rendering and it should help. Also avoid using fonts so small that portions use only 1 horizontal line. 2 lines should be OK.

William Hohauser
March 5th, 2007, 11:17 PM
I try this soon and report. The font is not that small but small enough. Producer's choice.

Scott Anderson
March 6th, 2007, 09:21 AM
William, when working on delivery for 60i, there's really only a few workarounds that can truly eliminate this shimmer, simply because of the nature of interlaced display.

Most likely, the flicker is the file horizontal details of the text bouncing up and down the upper and lower fields as the text rolls. Making a 30p composition doesn't really help, because depending on the speed, the fine detail can still bounce between fields when the comp is evetually displayed interlaced

One option is to use something like a flicker filter, which is really just a blur. I've also used a directional blur, set to vertical only - this maintains all the fine details in the vertical parts of the text, while blurring the horizontal enough to ease the transition between fields.

The best solution, however, is to scroll the text at a rate that always keeps the text on the same field. That means keeping the scroll at a pixels/second number that is divisible by 60. If you set the speed at 30, 60, 120 or 240 pixels/second, you'll find that the text stays rock-steady, no blurring needed.

In After Effects, this usually means adjusting the start and end keyframes in time to get close, then nudging the start or end position pixel by pixel until you get it just so - it has to be exact. Twirl down the position property to see the velocity graph. Sometimes 60.1 pixels/second will work, but I try to get it at a clean 60 (or 120, or 30).

The only downside is that you can tend to lose some resolution in smaller text, as whatever fine horizontal details that sit in one field never display. Usually it's a fair trade, as I said, because the text immediately becomes rock-steady. Sometimes getting it right, then adding in just a little bit of vertical blur or motion blur can make it look more organic.

William Hohauser
March 6th, 2007, 03:15 PM
That sound good as well. Unfortunately the scroll is locked into a music track with images coming up at synchronized points. I'll try all three methods suggested here and report back.

William Hohauser
March 12th, 2007, 03:48 PM
Report #1:

I found that all the credit graphics were moving at around 62 pixels per sec. so I fixed them as close to 60 pixels per sec as AE would allow, 59.98 to 60.01. That got rid of the shimmer, however the credits are a little diffuse now.

Next experiment: 30p