15 Replies Latest reply on Apr 27, 2016 6:09 AM by techinis

# Jerky rolling credits -- how can I solve?

I created a credit roll in after effects to premiere -- it does not flow smoothly, even after being rendered.  I googled it and it says to create a null but have no idea what they are talking about -- any thoughts?

• ###### 1. Re: Jerky rolling credits -- how can I solve?

Here's a thought developed through hard-won experience:  GETTING CREDIT ROLLS TO LOOK GOOD IS A PAIN IN THE NECK.  No fooling.  It's not a fun chore.

So why do they look so good on TV?  They're using preset roll speeds that take pixels and edges into account so the look remains consistent from frame to frame.  If you use just any old roll speed, AE's subpixel rendering kicks in to make edges look smooth, often at the expense of the thickness of top & bottom character edges, where it's most visible.

If your roll's vertical movement is in single-pixel increments -- not fractional increments -- the subpixel rendering stays consistent, end edges don't jump.  If you work with interlaced video, make that two-pixel increments.

Knowing this, you can see how it puts a big cramp on you speed selection.

To illustrate how tough it can be to do a good-looking credit roll, grab a DVD of the first Star Trek movie done by JJ Abrams.  Take a look at the credit roll at the end.  It looks like a train wreck.  That's a Hollywood movie!

• ###### 2. Re: Jerky rolling credits -- how can I solve?

There are several ways to get a smooth credit roll. One way that is easier for many to work with for timing is to create 2 keyframes for position that are 1 frame apart. Set the y value for the second key frame to be the number of pixels per frame movement that you need (say 2 pixels).

loopOut('continue')

Remember, your motion needs to be in whole pixels (and at certain, acceptable speeds), so tweak that number as needed.

• ###### 3. Re: Jerky rolling credits -- how can I solve?

The judder is caused by the interaction of the speed of the frame rate. Read this article from the FAQ section of this forum: FAQ: Why does horizontal motion stutter (judder) in my movies, such as during pans?

My article contains specific instructions for creating a smooth credit roll very easily. I have to disagree slightly with Dave that it's a pain in the neck. One simple expression and you're in perfect shape.

• ###### 4. Re: Jerky rolling credits -- how can I solve?

I suppose I left out a critical element: time.

"You've got a minute on the button for the credit roll."

"Yeah, but the roll doesn't look good unless it's at a minute-ten."

"Fix it."

That's when it becomes a pain in the neck.

• ###### 5. Re: Jerky rolling credits -- how can I solve?

Dave LaRonde wrote:

I suppose I left out a critical element: time.

"You've got a minute on the button for the credit roll."

"Yeah, but the roll doesn't look good unless it's at a minute-ten."

"Fix it."

That's when it becomes a pain in the neck.

True story.

How about, don't roll the credits? Many network shows have gone to flashing them up on the screen with no motion.

Bonus: when the show gets syndicated later on TBS, the credits don't blow by at an unreadable blinding speed when they speed them up, they just pop up quickly and you can at least make out what they say.

• ###### 6. Re: Jerky rolling credits -- how can I solve?

WWhere do you add this expression?

• ###### 7. Re: Jerky rolling credits -- how can I solve?

The position value. All it does is tell the layer once it reaches its last keyframe to keep moving that value at the same speed it was when it hit the last keyframe.

• ###### 8. Re: Jerky rolling credits -- how can I solve?

I found this wonderful template a few years ago and have been using it since.  Please share.

Silky smooth credit rolls in After Effects

http://www.strawberrycolor.com/clien...20v1.0.aep.zip

• ###### 9. Re: Jerky rolling credits -- how can I solve?

ok, but how do you use it?  create another layer with credits?

• ###### 10. Re: Jerky rolling credits -- how can I solve?

Here's a step by step method for creating a perfect credit roll every time in less than 5 minutes using a text layer. You can use the same technique using Illustrator or Photoshop to create your text but a text layer is easier.

1. Choose a sans serif font because the thin lines in a serif fonts cause problems in video unless the fonts are very large
2. Press Shift + Alt/Option + Ctrl/Cmnd = t to add a new text layer
3. Copy and paste your credit roll text from a text document to the new text layer
4. Make Set the paragraph style and font size to something that looks good
5. Set you Comp Panel Magnification Ratio (first box on the bottom right comp of the Comp Panel) to 800% or 1600% and the Comp Panel resolution to Auto so you can clearly see the top and bottom edge of your text
6. Here comes the first important part. If you insist on using white for your font color and a dark background then bring down the white value to something below 220 or compression will foul everything up with compression artifacts when you render
7. Carefully check the top and bottom edges of your text. In this case there is some sub pixel sampling fouling up the top edge of the "T"
8. Hold down the Ctrl/Cmnd key and drag the font size slowly up or down to minimize the aliasing on the top and bottom edge of your font. If the baseline is set to zero you should not have to adjust the baseline. Then adjust the leading so that each new line has the same look and aliasing is minimized.
(NOTE: Holding down the Ctrl/Cmnd key lets you drag values in the comp panel with 10 times the precision as just dragging them. If you are using Photoshop or Illustrator files for your font size you can make these adjustments in either app by zooming in. If you are in Illustrator you must have pixel preview turned on to see the aliasing problems and fix them. If someone else prepared the files you can use the "y" scale to line up the edges and set the starting Y position.)
9. Now you have the text lined up with the pixel grid so that it looks as clear as you can make it look. Change the Composition Panel's Magnification Ratio back to 100% or 50% so you can see the entire composition. DO NOT use Fit because Magnification Ratios like 45% will foul up the preview and make you needlessly worry about the credit roll.
10. Add this expression to the Position Property of your text layer by holding down the Alt/Option key and clicking on the Position stopwatch. You can copy and paste from this post:

s = 3; // speed

y = value[1] - time/thisComp.frameDuration * s;

x = value[0];

[x, y]

11. Grab the Text Layer and move the text to the bottom of the frame making sure that you don't position the Y value on a half pixel and foul up the top and bottom edges of your text
12. Turn on Motion Blur for the text layer and the comp, make sure the shutter angle for the comp is set to at least 180º and the phase is -90º (generally phase should be -half the shutter angle). Preview and check the speed. If you want the credits to move faster change the "s" value to 4 or 5. Use whole numbers. Some speeds may give you stroboscopic effects which are worse at lower frame rates. If you are rendering interlaced video then the speed should be even numbers. Your preview may stutter a bit in the comp panel because of screen refresh rates and frame rates or AE's current preview/cache problems but if you are paranoid you can check the comp a frame at a time. Comp frame rates of 29.97 will produce smoother looking credit rolls than 24, 23.976 or even 25(pal). If you use 24P as your format you must realize that broadcasters in NTSC land will add a synthesized 3:2 pulldown to your video and the credit roll will have funky aliased edges every third frame where two fields are combined to make one frame.

Let me explain the expression line by line. The first line declares a speed variable that defines the number of pixels the layer will move per frame. The second line defines the "y" value for position by taking the original value for y and subtracting time divided by the duration of a single frame then multiplying that value by the speed variable. The next line just calls up the "x" value for the layer. The last line puts the defined "x" and "y" values in an array that can be used to position the layer.

One other thing. If you need to change the timing of your credit roll and it will not fit using a whole number for "s" then you change the leading in the text layer so the lines are closer together or farther apart. Make sure that you go back to a Magnification Ratio of about 800% and check the top and bottom edges of your text.

That's all there is to it. To save yourself time in the future select the position property of the text layer and save this animation as an animation preset. There already are two presets that kind of do the same thing but they tile the movement. They are Autoscroll horizontal and vertical. I prefer my method because the Autoscroll presets repeat the roll as a loop and most of the time I don't want that.

• ###### 11. Re: Jerky rolling credits -- how can I solve?

okay, so I imported my credits from photoshop but noticed that the resolution is not great -- do I bring down the composition that has the appropriate resolution?  What is my next step after using this template after I import the credits that I have?  Thanks so much

• ###### 12. Re: Jerky rolling credits -- how can I solve?

How wide is your Photoshop file? If it were me I would convert the text layer in Photoshop to Editable text and use the text layer and my steps for your credit roll. It sounds like you might be new to video production and don't have a clear understanding about frame sizes and resolution. Video is pixels, print is DPI, resolution is the total number of pixels not the DPI. If you Photoshop document has too few pixels then the resolution is low and you can't fix anything by scaling it up unless there are vector elements in the PSD. If your Photoshop file is 4 or 5 times the number of pixels wide that your video is then it is probably too big. Basically any raster image that you include in a video should be at 100% scale at some point in the project and not larger than about 125% or it will fall apart. If your image (PSD, JPG, TIFF) is never more than 25% or even 50% then the file is much bigger than it needs to be.

Hope this helps.

• ###### 13. Re: Jerky rolling credits -- how can I solve?

thanks I was already able to create a credit roll -- with no problems with resolution, my problem was a slight jerkiness to the credits == so if I redo it using the suggestion before you and I open the layer up in After effects -- it's fine, it's when I use the other template -- not yours, that's where I see that the resolution is not clear.

• ###### 14. Re: Jerky rolling credits -- how can I solve?

The template has all the comps set to "Quarter" resolution for preview (that's just how the person saved it I guess). If you change it to "Full" it will look proper.

Basically, you create a photoshop or illustrator file that is the same width as your final output (say 1920px), then however tall you need to fit all your credits (you may need more than one for a really long credit roll).  Duplicate the comp for the resolution that you need, add the credit list to the comp, and gang it to the NULL object.  Then, at the first frame, set the vertical position of the credit list so that it starts just off screen.  If you scrub forwards then it will roll up.  If you to adjust the speed, open up the NULL object and adjust the "rate" in the position expression.  Be sure to keep it a whole number (no decimals) or you will see jitter.

Also, the "•PLAY THIS COMP FIRST" comp has some good tips in it.

• ###### 15. Re: Jerky rolling credits -- how can I solve?

Hi Rick,

looks like you have the solution here. But I have difficulty trying to do it. I guess it is because I'm not an expert on AE.

Some terms you use I'm not familiar too.

Tell me, do you have a AE file that you can send me and that works great ? I guess I would be able to start from there!

I tried the other link that Scott Mckenzie propose but the credit still doesn't look good enough for me.

Thanks for you help