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Time stretch won't stretch over 3 seconds, why?

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ryan elder
Time stretch won't stretch over 3 seconds, why?
on Mar 16, 2018 at 2:48:25 am

Basically I have a com that is 4 and a half seconds almost. One of the layers is just one frame, that I want to stretch out to last the entire comp. But for some reason the time stretch effect will only stretch it out to 3 seconds and nothing over, even though the rest of the layers in the comp are 4 and a half seconds. Does anyone know why this is?


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Steve Bentley
Re: Time stretch won't stretch over 3 seconds, why?
on Mar 16, 2018 at 3:52:46 am

There is a limit to the stretch effect - 9900 %
If you go into prefs you can have a frame fill the comp (its under import) or be any other set length.
You can also enable time remapping on the layer and you can then extend its out point to the end of the comp.

Am I missing something? Time stretching a frame wont make the motion last any longer because on one frame there is no motion.



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ryan elder
Re: Time stretch won't stretch over 3 seconds, why?
on Mar 16, 2018 at 4:35:07 am

Okay thanks. I never knew about time remapping and it seems to have worked! Thanks.

Basically I want to stretch one frame into several frames of that one frame. The frame is a wheel, and I want the wheel to spin, while superimposed on other footage. If that makes sense?

I also tried turning on motion blur to make the wheel spin more convincing looking. However, I can't really tell a difference with motion blur turned on or off, unless maybe it has to spin fast in order to tell?


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Steve Bentley
Re: Time stretch won't stretch over 3 seconds, why?
on Mar 16, 2018 at 6:31:37 am

If you just want to see it in the comp, you have to turn motion blur on in two places - on the footage layer itself and up at the top of the timeline window there is a matching icon (two over from the shy icon and one to the left of the motion graph editor button). Turn that on as well and the blur will show up in your comp (assuming that the object is moving or rotating).
That top button is there so you can designate certain layers to be motion blurred in each layer but leave leave the overall effect off when you are working with your comp as it takes longer to process that effect. Think of it as a global motion blur button (but only for layers that have their own motion blur turned on.)
The default settings for rending tells AE to turn on that top button when rendering but it couldn't hurt to check in your render settings that it is indeed set to on for rendering.
If you want to make the blur more or less, you can adjust the shutter angle in the comp settings window (cmdK or cntrlK) under the advanced tab. The default is 180 degrees which refers to how a motion picture camera used to work (their shutters were circles with a wedge cut out that light in - the wider the wedge/angle the longer the film was exposed and thus a longer blur). So a higher blur would be in the 270 degrees range - but more than that it starts looking unreal, unless that's what you are after.



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ryan elder
Re: Time stretch won't stretch over 3 seconds, why?
on Mar 19, 2018 at 2:57:55 am

Okay thanks. I tried clicking on both icons but can still see no motion blur. Perhaps the wheel is not moving fast enough for there to be a lot of motion blur maybe, as it's suppose to move slowly. I just want the regular 180 degree motion blur :).

However, when I click on the motion blur icons, the clip all of a sudden becomes a third shorter, and there is no way I can stretch it back out to it's length without ruining other parts of the effect. For example, there are key frames that zoom in on the wheel and change the position of the wheel, and if the clip becomes shorter from adding motion blur, and I try to stretch it back out, then I loose the keyframes.

Is there anyway to fix this?


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Steve Bentley
Re: Time stretch won't stretch over 3 seconds, why?
on Mar 19, 2018 at 3:57:16 am

Can you post the project? I've not seen a layer shrink unless the originating footage changes. I don't know how a motion blur would make a layer shrink.
Even with a slowly turning wheel you should see a little blur.
Something is up here.



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ryan elder
Re: Time stretch won't stretch over 3 seconds, why?
on Mar 20, 2018 at 4:50:12 am

Okay thanks. When you say post the project do you mean a test video of what I have done so far, or actually post what I tried doing in after effects?


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ryan elder
Re: Time stretch won't stretch over 3 seconds, why?
on Mar 20, 2018 at 4:57:10 am

Another thing is, is that I am working in Premiere Pro, and from Premiere Pro, I send the clip to after effects and then add the motion blur, but the wheel only turns in Premiere Pro. Could the motion blur get lost when it goes back to Premiere Pro from After Effects, since I am turning the wheel in Premiere Pro?


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Steve Bentley
Re: Time stretch won't stretch over 3 seconds, why?
on Mar 20, 2018 at 5:58:57 am

The key frames that turn the wheel need to be in the application that is adding the motion blur/ Its the animating that does the blur - once it is just a set of pixels you would need realsmart motion blur or some other package to pick the motion out of the footage to determine the blur - and that doesn't always work as you might expect.
So if you did the animation in Premier and brought that footage into AE, all AE knows is that its just a movie. It has no motion data to work with.



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ryan elder
Re: Time stretch won't stretch over 3 seconds, why?
on Mar 20, 2018 at 9:38:41 pm

Okay thanks, so you are pretty much saying that AE cannot read the motion of the wheel in Premiere and I would have to rotate the wheel in AE then?


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Steve Bentley
Re: Time stretch won't stretch over 3 seconds, why?
on Mar 20, 2018 at 9:50:29 pm

Correct. AE measures the values between one keyframe and the next and then does the math to figure out how much motion blur to apply. No keyframes come from premiere (that I'm aware of - but I'm not a premiere guy). What comes out of premiere is just a movie. You might be able to export keyframe data in an edl but I doubt it. Do the animation in AE (where it should be done anyway for best control) and apply the motion blur there and then bring that rendered element back in to Premiere (with alpha if needed)

You could apply a smart motion blur effect like Real Smart Motion blur which can look at the pixels and figure out the blur from a movie that has no motion blur on it but the effect has its limitations (and it's not cheap) - if something comes in from an edge the effect doesn't know what to do with those new pixels because as far as it's concerned they haven't started moving yet, they just appeared. Overlapping objects at different speeds can also cause trouble. Its not perfect but it is impressive given what it's got to accomplish. It's literally tracking every pixel. A doff of the propeller beanie to the guys who invented that!



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ryan elder
Re: Time stretch won't stretch over 3 seconds, why?
on Mar 20, 2018 at 10:03:16 pm
Last Edited By ryan elder on Mar 20, 2018 at 10:09:23 pm

Okay thanks. But when I send the clip from Premiere into After Effects, AE shows the keyframes. The keyframes are exactly the same in AE as in Premiere. So it seems that AE can read the keyframes, unless there is a miscommunication between programs?


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Steve Bentley
Re: Time stretch won't stretch over 3 seconds, why?
on Mar 20, 2018 at 10:09:35 pm

I wasn't aware you could so that (bring a premiere project into AE with animation keyframes intact - but again I don't use premiere)
It wouldn't surprise me that rotation didn't come in because so few of adobe's package play well together.
But then again if position and scale come in then rotation should too.
In Ae you can hit the attribute to light up all the keyframes and then hit copy. Then you can paste that data into a spread sheet or text doc. Perhaps you can do the same for premiere and then paste that data onto the rotation attribute in AE? Just make an initial keyframe in rotation in AE and paste the premiere rotation date on top of it.



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ryan elder
Re: Time stretch won't stretch over 3 seconds, why?
on Mar 20, 2018 at 10:11:59 pm

Actually I looked it and it turns out rotation did come in. Sorry my mistake, I assumed it didn't come, cause the motion blur wasn't being applied. But the keyframes from rotation are there as well. AE though, for some reason, still makes the clip shorter, after I send it from Premiere, so I have to then use time remapping to make it longer.

Still trying to figure out why AE is making it shorter. It's just this one clip for some reason that AE does that too.


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ryan elder
Re: Time stretch won't stretch over 3 seconds, why?
on Mar 20, 2018 at 10:17:56 pm

Maybe it's just my eyes and I am not seeing the motion blur. Can you see it on the wheel?







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Steve Bentley
Re: Time stretch won't stretch over 3 seconds, why?
on Mar 20, 2018 at 10:27:16 pm

It seems to be there on the perspective shot but not on the overhead shot. (the pegs that are real are blurred but your text is not)
The shortening of the layer may be due to the footage from premiere being a different FPS than the AE comp.
Check in the project footage and hit interpret footage under the file menu to see what fps AE thinks it is. It should match your comp fps or the footage will shrink or grow in time.
AE doesn't really know about FPS. It works in discreet frames so its best if you can match one frame of footage to one frame of comp time.
Wanna post the project and I'll have a look? Footage not required.



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ryan elder
Re: Time stretch won't stretch over 3 seconds, why?
on Mar 20, 2018 at 10:31:30 pm

Okay thanks, I might not be able to post the project for a while cause I would have to video record myself doing it which I do not have access to a steady camera right now for.

It could be a frame rate mismatch. Basically in Premiere, the wheel was only one frame, so I used the rate stretch tool to stretch the frame out into several frames to take up the length I wanted the wheel to run for. So it's just one frame originally stretched to 4 seconds worth of frames. So not sure what the frame rate originally would be since it's just one frame to count from.


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Steve Bentley
Re: Time stretch won't stretch over 3 seconds, why?
on Mar 20, 2018 at 10:39:06 pm

Ah ok. The stretch tool might not be compatible with how ae does it.



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Steve Bentley
Re: Time stretch won't stretch over 3 seconds, why?
on Mar 20, 2018 at 10:40:51 pm

post just the ae file? The footage will be missing but I'll be able to tell whats going on.



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ryan elder
Re: Time stretch won't stretch over 3 seconds, why?
on Mar 20, 2018 at 11:20:26 pm

Okay thank you very much, but I'm not sure what you mean? Do you mean a video display of it, or the propery information of the file?


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ryan elder
Re: Time stretch won't stretch over 3 seconds, why?
on Mar 20, 2018 at 11:24:32 pm

I tried applying the motion blur again. Did it work now?







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Steve Bentley
Re: Time stretch won't stretch over 3 seconds, why?
on Mar 20, 2018 at 11:56:02 pm

ya that looks like you've got it. You might want to make the AE comp have a 270 degree shutter angle instead of 180 in the advanced tab of the comp settings (cntlK); it seems to need a bit more blur to match the pegs going around. The spin of the wedges of the wheel dont really match the spin of the real wheel either so you might want to tweak your acceleration curve of the rotation.



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ryan elder
Re: Time stretch won't stretch over 3 seconds, why?
on Mar 21, 2018 at 12:15:50 am

Okay thanks. I was trying to adjust to the pegs, but I can't seem to keep up with the, cause the key frames become more obvious when I try to keep up with the pegs exactly. But I will keep trying. I thought that the actual wheel of fortune TV show was shot at a 180 degree shutter speed though, so why would 270 be the one to choose?


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Steve Bentley
Re: Time stretch won't stretch over 3 seconds, why?
on Mar 21, 2018 at 2:25:07 am

Broadcast video cams don't really have shutters per se. They do blur but not in the traditional movie shutter sense. I was thinking it just needed more blur to match the pegs and you can either increase it with a motion blur effect or just jack up the shutter angle and let AE's built in blur do the trick.
If you can match the initial speed of the wheel, use the animation curve editor to taper that speed out to where the real wheel stops (if you can) it should be fairly linear right up to the end where it will be a curve.



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ryan elder
Re: Time stretch won't stretch over 3 seconds, why?
on Mar 21, 2018 at 5:32:27 am

Okay thanks, I haven't used the animation curve editor before, but will try it. However, Premiere Pro froze and I think this has now caused the motion blur to go away now.

But it's really hard to tell because I cannot tell the difference in the video with motion blur compared to without, where as you seemed to be able to. How do you tell if is motion blur by looking?


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Steve Bentley
Re: Time stretch won't stretch over 3 seconds, why?
on Mar 21, 2018 at 5:37:48 am

First remember to turn on the AE comp's motion blur button and not just the layer's. Then try jacking the shutter angle up to something silly like 600 which will overdo the blur. Premier should have nothing to do with the blur except for sending the rotation keyframes into AE. Are you rendering out of AE and then importing the movie back into premier or just importing the AE project back into Premier?
It might be your pipeline thats at issue. I don't think you can import premier into AE and then import that AE project back into premier - that would be like the snake that eats its own tail.



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ryan elder
Re: Time stretch won't stretch over 3 seconds, why?
on Mar 21, 2018 at 11:30:41 am

Okay thanks. Basically I right click on the clip in Premiere and then click on "replace with after effects composition".

This sends the clip out of Premiere into after effects, and then back into Premiere after.

However, I cannot tell if there is motion blur or not.

The reason why I don't want to make a movie out of AE is that there is still work to be done on it in Premiere and if I make the movie in AE, it can put me behind in other ways since it's not finished left and there is still Premiere work to do.

I may want to adjust the rotation in different ways, as well as the position, etc. So I don't want to finish the effect right after adding the motion blur so to speak. It's hard to tell if it plays with motion blur in AE. I assume it does, since it's on, but it plays it in a jittery way in AE, compared to Premiere.

But when I send clips into AE from Premiere, AE can add an effect and then it will show up in Premiere. Like for example, if I add a color to it in AE, the color will then show up on the clip in Premiere. So it works for everything else pretty much.


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Steve Bentley
Re: Time stretch won't stretch over 3 seconds, why?
on Mar 21, 2018 at 8:16:16 pm

That sounds like it would be a good pipeline to keep things "live". But because the motion blur is not an "effect" that could be shared between apps (it's really the comp looking after that for you- perhaps premier has a shutter based motion blur on its comps?) it may need to be rendered in AE to make pixels that blur.

I just can't believe, given Adobe's history, that Premier and AE are that aligned/transparent to each other. Every effect would have to work in exactly the same way, in the same color space, with the same kind of motion graph editor. The stack order, easing algorithms, and blending functions would all have to be identical - even the way you can extend footage in AE: I'll bet dollars to donuts can't be done in Premier (and hence your shortening clip length)
Premier used to be an editor, so if you wanted complex motion or effects added you went to AE and rendered those and brought the resulting footage back in. The motion curves in Premiere were just so primitive you just couldn't do the things you could do in AE. But that was back then, and perhaps I need to look at Premier again, especially since Final Cut has lost its mind.
It's always seemed to be Adobe's policy to keep every app's specialty separate (it's why we don't have a stellar paint plugin in AE, which is desperately needed, even though Adobe owns the preeminent Paint package)



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ryan elder
Re: Time stretch won't stretch over 3 seconds, why?
on Mar 21, 2018 at 9:39:49 pm

Oh okay thanks. Well when I asked you before if the last shot of the wheel had motion blur on it, you said yes. That was sent from Premiere into AE, and then I clicked on the motion blur (which caused me to have to extend the clip, cause it was shortened). Then the same clip in Premiere must have had the motion blur on it, cause you said you could see it, right?

However if Premiere freezes, then the pipeline for the motion blur seems to crash, but it's hard to tell since I have trouble seeing motion blur.


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ryan elder
Re: Time stretch won't stretch over 3 seconds, why?
on Mar 21, 2018 at 10:04:35 pm

I tried rendering out the clip again, is the motion blur still in the shots?







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Steve Bentley
Re: Time stretch won't stretch over 3 seconds, why?
on Mar 21, 2018 at 10:19:13 pm

There is definitely blur there on the overhead shot. I went to compare it to the first movie you sent which had none but its already been taken down.
I think any client would be ok with this level of blur. When there is none it sticks out like a sore thumb and if I have to really look it means there is probably enough.



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ryan elder
Re: Time stretch won't stretch over 3 seconds, why?
on Mar 21, 2018 at 10:28:48 pm

Sorry, youtube wouldn't allow me to have two of the same video, so I had to take the previous down. But this one definitely has blur in it for sure in both shots then?


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Steve Bentley
Re: Time stretch won't stretch over 3 seconds, why?
on Mar 21, 2018 at 10:32:20 pm

I would say so - to my eye it needs more, but it's not killing me. I don't think any client would call you on it.



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ryan elder
Re: Time stretch won't stretch over 3 seconds, why?
on Mar 21, 2018 at 10:43:49 pm

Okay thanks. I'm more use to editing but this client wants me to do more effects than what I am use to.

I took footage from the actual wheel of fortune show and then changed it around. However, isn't the show wheel of fortune shot at a 180 degree motion blur? Cause if so, why would the new FX wheel, need a higher motion blur than the show?


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Steve Bentley
Re: Time stretch won't stretch over 3 seconds, why?
on Mar 21, 2018 at 10:55:40 pm

There is no set angle for the shutter to be set at in filming - its all a dance between how much light you have to work with, the F stop you need for depth of field, the "speed" of the film or CCD and the kind of effect you want (the battles in Gladiator were shot with a very very narrow angle of shutter and tons of light to give it a strobey look and reduce the motion blur to nill).
But Broadcast cameras used in a studio don't really have a shutter per se. And even if they did I doubt it would be a rotary one. You match the blur so it matches by eye - the shutter angle is just a number so you know if you need more, you need to increase the angle. The great thing about this is if you really want a lot you can go to 1000 or more, where a real shutter can't be open more than all the way (360).
We get a lot of camera data when we're doing match moves but we rarely get shutter data even when its on film. So the eyeball and reference is the best judge.
If the shot is still bugging you it's probably the mismatch between the speed of the animated element and the real wheel. The blur you have done is very passable.



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ryan elder
Re: Time stretch won't stretch over 3 seconds, why?
on Mar 22, 2018 at 12:42:06 am

Okay thank you very much for the help. I rendered out a high quality version of what I have so far to be safe, but could tinker with it some more down the road, when the project is all finished and I have fresh eyes on the whole thing.

I thought that almost all TV shows choose the 180 degree shutter speed specifically, to keep that same look all the time. Even when I went to film school and worked with other people on shoots, they filmmakers choose to shoot 180 for the entire movie to keep a consistent look. If the camera needs to adjust to the light, they will usually adjust the gain, rather than the shutter speed cause the gain can be adjusted while still looking more consistent compared to shutter speed, no?

I tried lining up the wheel with the peg more but the wheel sort of jolts in a way I don't like when I do that. But I can keep playing around with it.


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Steve Bentley
Re: Time stretch won't stretch over 3 seconds, why?
on Mar 22, 2018 at 8:30:34 pm

in AE you might be able to track a few pegs to get a rotation speed out of it. I say might because the center of the circle (the rotation point) is outside frame all the time, so not sure if that would work.



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