-
Real life light streaks – problems with continuity and flickering
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.
-
14 Replies
-
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 | RenderBreak [blog] | Profile [LinkedIn] -
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 🙁 )
-
[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 | RenderBreak [blog] | Profile [LinkedIn] -
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?
-
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 -
Try precomp again and add another echo effect.
-
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? -
[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 | RenderBreak [blog] | Profile [LinkedIn] -
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)? -
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 | RenderBreak [blog] | Profile [LinkedIn]
Reply to this Discussion! Login or Sign Up