ADOBE AFTER EFFECTS: Forum Expressions Tutorials Creative Cloud

Real life light streaks - problems with continuity and flickering

COW Forums : Adobe After Effects

<< PREVIOUS   •   FAQ   •   VIEW ALL   •   PRINT   •   NEXT >>
Ori Kuper
Real life light streaks - problems with continuity and flickering
on Nov 18, 2014 at 3:07:57 am

Hello,
I'm trying to create a light streak based on a real life footage (not a particle emmiter).
I used few simple sticklights, filmed myself on 60fps 720 (Canon 60D, so it's an H264 based MOV file), applied the echo effect in AE, and i still have 2 problems:

1. No matter how much I play around the echo settings, I never get a good smooth one line, but rather a dotted line. Is this a function of FPS of the footage, or am I doing something wrong with the settings? it's a 60 fps footage, and yes i was moving with the lights pretty fast, but... was that too fast to achieve one line?? It looks fine on the footage, but only becomes dotted after i apply the echo to it. Using motion pixel blending does help a little bit, but still not giving me one smooth line.

2. When rendered, the final file looks flickery much on the lines of lights. It almost looks like I was filming a screen or bulb with a different 'updating rate'... any chance I can get rid of this flickering look?

I'm attaching a screen shot of the echo settings, and i'll try to add also a small version of the rendered file..

any ideas of how to handle those 2 problems would be very appreciated. Thanks! Ori.



Trying light streaks render



Return to posts index

Walter Soyka
Re: Real life light streaks - problems with continuity and flickering
on Nov 18, 2014 at 2:39:40 pm

For a streaky look, you would want to record this with as long as exposure (low shutter speed) as possible.

1) If it looks fine on the footage, what are you trying to accomplish with Echo?

2) What do you mean by "flickery look" on render? Unfortunately the attached clip is too low-res to see what's going on here.

Walter Soyka
Designer & Mad Scientist at Keen Live [link]
Motion Graphics, Widescreen Events, Presentation Design, and Consulting
@keenlive [twitter]   |   RenderBreak [blog]   |   Profile [LinkedIn]


Return to posts index

Ori Kuper
Re: Real life light streaks - problems with continuity and flickering
on Nov 18, 2014 at 4:36:10 pm

Thanks for your reply Walter!

If it was a stills photo, I know I can use the lower shutter speeds (or even bulb mode) to 'paint with the light' in it. But unfortunately in the video mode on this camera, the lowest I can go on shutter for this is 1/60; I'm trying to keep myself a smooth (as possible) slow-motion ability for later, and therefore shooting on 60fps (the highest this cam can give me). My canon 60D won't let me go below my fps, but I'll try to see if i can override it with ML. I'm using echo for case that my current footage is the only one i can get and there is NO way to override the shutter.


1. The footage looks fine in terms of 'not dotted'. but since I can't really see any streaks visually STAYING on the screen (continuous line as I would have seen in a 'light painting' stills shot), I planned to let echo to create that continuous line/streak of light for me...

2. I'll try to render a small piece and post it here in full-res. It's gonna take some time though (using a strong, but still, laptop :( )


Return to posts index


Walter Soyka
Re: Real life light streaks - problems with continuity and flickering
on Nov 18, 2014 at 4:43:46 pm

[Ori Kuper] "1. The footage looks fine in terms of 'not dotted'. but since I can't really see any streaks visually STAYING on the screen (continuous line as I would have seen in a 'light painting' stills shot), I planned to let echo to create that continuous line/streak of light for me..."

Ah, now I understand.

You are using the Add mode for your echo operator, meaning the previous frame is composited over the current frame with an Add blend mode. Where a pixel is completely dark in one frame and partially light in the other, you get a partially light result (0 + 0.5 = 0.5). But where two pixels are both partially light, adding them together makes the result even brighter (0.5 + 0.5 = 1).

Change the echo operator to Maximum, which will yield the brightest value over the echoed frames.

Walter Soyka
Designer & Mad Scientist at Keen Live [link]
Motion Graphics, Widescreen Events, Presentation Design, and Consulting
@keenlive [twitter]   |   RenderBreak [blog]   |   Profile [LinkedIn]


Return to posts index

Ori Kuper
Re: Real life light streaks - problems with continuity and flickering
on Nov 18, 2014 at 4:58:49 pm

That makes a lot of sense for the 'flicker' problem! Thanks, that saved me from keeping waiting for that sample render. For now at least! ;)

Now that I made it Maximum, the whole thing looks less bright, but I'm gonna try and compensate on that with 'glow' with about 0.5 intensity and a radius of 0. (if any opposing, please feel free to say so).

I'll try and render a small version again, and see if I get the flickery look out of the way with the new MAX operator.

I'm still not sure how to get it all to be one line(as if i was 'painting with light' in a stills shot), instead of the bunch of light chunks with gaps between them . Any ideas how to achieve that with my setup?


Return to posts index

Walter Soyka
Re: Real life light streaks - problems with continuity and flickering
on Nov 18, 2014 at 8:24:41 pm

[Ori Kuper] "I'm still not sure how to get it all to be one line(as if i was 'painting with light' in a stills shot), instead of the bunch of light chunks with gaps between them . Any ideas how to achieve that with my setup?"

I think that the light moves too much from one frame to the next for a smooth streak.

I'd suggest time-remapping (with Pixel Motion frame-blending) to make a slow motion version (thus synthesizing new frames with light in between the existing frames, filling in the gaps), then using Echo.

Walter Soyka
Designer & Mad Scientist at Keen Live [link]
Motion Graphics, Widescreen Events, Presentation Design, and Consulting
@keenlive [twitter]   |   RenderBreak [blog]   |   Profile [LinkedIn]


Return to posts index


Ori Kuper
Re: Real life light streaks - problems with continuity and flickering
on Nov 18, 2014 at 8:32:36 pm

Walter - right now i'm using pixel motion on it as it is - no slow mo and no time remap, which, as I said earlier helped a bit.
Tell me if you understand your suggestion correctly:
time remap using pixel motion (to fill in more gaps) > precomp > bring the precomp to a new timeline and slowmo the precomp back to achieve regular time (with filled in gaps)?


Return to posts index

Walter Soyka
Re: Real life light streaks - problems with continuity and flickering
on Nov 18, 2014 at 8:41:10 pm

Take the footage. Use time-remapping with pixel motion to slow it down. Precomp this. Edit the comp settings and enable "Preserve frame rate when nested or in render queue."

Apply Echo to the precomp.

Precomp again. Edit the comp settings and enable "Preserve frame rate when nested or in render queue."

Use time remapping to restore its original speed.

Walter Soyka
Designer & Mad Scientist at Keen Live [link]
Motion Graphics, Widescreen Events, Presentation Design, and Consulting
@keenlive [twitter]   |   RenderBreak [blog]   |   Profile [LinkedIn]


Return to posts index

Ori Kuper
Re: Real life light streaks - problems with continuity and flickering
on Dec 28, 2014 at 8:07:47 am

I've been trying few things, one of them was to get a brand new SSD. Now that i'm back on it, I'm trying to make the work a little easier on the system, but getting some unwanted results. Maybe you can tell me why it happens?? I'm attaching print screen of the previews, of each of the 2 options that i'm trying to work with.






The process:
Originally I had both Levels AND Echo effects applied to my original footage. The processing of both effects together was very heavy on the system, so I decided to render the original footage with ONLY the LEVELS effect applied, then bring that rendered file into AE, and apply ONLY ECHO to it (since it's 'ready to go levels wise').
Both the original and rendered are 60fps, so i thought i'm not missing any data there.

The problem:
The results look different; the original file with both effects on it, creates a way smoother 'streak of light' with no gaps. The rendered file with the Echo only on it, creates gaps in the line.

I understand that the original file, with the echo applied to it, is using ALL the info that was on the footage even before the in-frame, therefore at any point on the timeline, this line would have more 'history frames' behind it (and will create longer streaks). But I don't think that issue would cause it to be more/less smooth...

So - what is it, that creates those 'gaps' in my lines, when i'm using the pre-rendered file and just applying the Echo to it?
Any ideas?


Thanks, Happy holidays and Happy new year!
Ori.


Return to posts index


Ori Kuper
Re: Real life light streaks - problems with continuity and flickering
on Mar 31, 2015 at 5:06:47 pm

I'm back for more!!
So i finally had a chance to check this effect while test shooting for few mins in 60FPS. It sure looks better (no gaps in the line). Now I have another question - more editing/general workflow - but since I already started here - I'll ask it here first:
Lets say I want to create a simple light streak, shaped as a circle, while creating a 'fast forwarded' action; Imagine a person holding a light in their hand towards the camera, arm fully extended, creating a circle with their arm. To the camera it looks clockwise.
The beginning is just a regular cutting process:
1. I want to take that footage, slow-mo the shot in Premiere to 50%, and then cut it in a way that would show only around the times when the arm is at 12,4,8,12 - 'skipping' the parts in between. BUT:
I want the light streak (to be added in AE) to be FULLY created and shown. w/o gaps. For which I'm afraid I will have to:
2. Take the FULL ORIGINAL shot as is, bring it to AE, create the light streak over the WHOLE shot, render it out as a FULL shot again, replace the shot in PP project with this final render of the shot.
The problem I have with this - I'll have to process and render a full shot, even though at the end I'll only be showing less than a 1/4 of it. The problem becomes even worse, when I'm planning on doing it with multiple, different shots.

Any idea how I can avoid that 'full go-around' per EACH shot (or that shot's cuts)? A way to work 'only with the cuts I really need' which will STILL create a fully made light streak shown?

Thanks!
Ori.


Return to posts index

Ori Kuper
Re: Real life light streaks - problems with continuity and flickering
on Nov 18, 2014 at 5:58:54 pm

Well, it didn't help :( at least not yet, maybe i'm missing something. It probably did give all the light dots/chunks the same brightness, but it still flickery in its look. ****I believe the flicker here comes due to the fast movement, not due to wrong settings, I just still don't know how to eliminate it****

While i'm rendering a full res 2 secs file, I'm attaching here the small rendered file, after the max operator was applied, and also a small frame capture with a marked area in it.

If you don't mind, please look at the pic to see WHERE to look for that flicker coming, and then please check the video. After you'll see it in that area, you'll be able to see it also on other areas more easily...

Thanks!

Where to look for it??


and link to the small, new video:
8202_maxoperatorrender2min.mov.zip


Return to posts index

Richard Garabedain
Re: Real life light streaks - problems with continuity and flickering
on Nov 18, 2014 at 8:09:54 pm

Try precomp again and add another echo effect.


Return to posts index


Ori Kuper
Re: Real life light streaks - problems with continuity and flickering
on Nov 18, 2014 at 8:18:56 pm

Thanks Richard, any suggestion of what settings should i used for the echo on the precomp layer?
I tried copy pasting the current echo, but it just creates a 'longer trail' but not a 'smooth trail'.
As in - it doesn't FILL in the current gaps :(
ideas?


Return to posts index

Ori Kuper
Re: Real life light streaks - problems with continuity and flickering
on Nov 18, 2014 at 10:05:26 pm

Walter - that sounds good, although i'm not sure i'm a huge fan of the 'creating pixels from scratch' thing. BUT I might try that too!

In the meanwhile I took Richard's advice and been trying the precomp and echo-process multiple times; i got some nice results with 'closing the gaps', at least per a still frame. Attached here.



Since I'm using a laptop system, that by today's graphic standards would be considered 'very weak', my questions now are:

1. What would be using more resources/power for rendering (preview AND final product); the time remapping process you mentioned above, or the multiple precomps with the echo on each (as i show here)?

2. If I wanted to get a desktop system that is capable of such job(s), and on our era's footage (4-6K) - what do i need to make sure to have in it? I know it's a huge can of worms, never ending, maybe not for this forum, question - but for now lets say 'just for this specific job with AE'..

p.s. tried to re-precomp again and boom my AE crashes. And of course the last few precomps with the echo settings were not saved. Yay for trial and error again from scratch and hence why i need a new system :(


Return to posts index

Chris Wright
Re: Real life light streaks - problems with continuity and flickering
on Nov 18, 2014 at 10:39:49 pm
Last Edited By Chris Wright on Nov 18, 2014 at 11:47:48 pm

you could try timewarp 100% but manual shutter blade blur like 4000 to even out the dots. It's similar to reelsmart motion blur. or cc forcemotion blur.

cc vector blur is designed to blur dots.


Also, depending on flicker, if the above doesn't work, you can timewarp 50%, then precomp that and then right click timestretch 50%. The speed will be the same but it will create intermediate frames to average out the flicker.


Return to posts index

<< PREVIOUS   •   VIEW ALL   •   PRINT   •   NEXT >>
© 2017 CreativeCOW.net All Rights Reserved
[TOP]