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Problem with fade to black of layered clips with white backgrounds

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David Meister
Problem with fade to black of layered clips with white backgrounds
on May 7, 2014 at 8:19:42 am

Hello,

in my timeline I layer a person on a white background over a white page with text on it. In order to make the two fit I crop the clip with the person and match the two whites with the help of color correction. Up to here everything works perfectly.

But if I now fade the whole thing to black the whites immediately start to diverge and it becomes very ugly and visible that sequence consists of two layered clips.

Does anybody have a solution to this? Here's what I tried:

- Fade one clip
- Fade both clip
- Make a compound clip
- Keyframe the opacity instate of the fade transition
- export to quicktime and reimport

Nothing works to my satisfaction. The only thing that worked was exporting each clip seperately as an image sequence, import both into AfterEffects and create the fade there.

But that shouldn't be necessary in a programme that calls itself professional, should it? Or is the user the problem?

Thanks for your help.

David


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Jeremy Garchow
Re: Problem with fade to black of layered clips with white backgrounds
on May 7, 2014 at 12:10:35 pm

Dissolve to a black color solid above all the layers.


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David Meister
Re: Problem with fade to black of layered clips with white backgrounds
on May 7, 2014 at 12:35:17 pm

Thanks for your idea. Unfortunately it doesn't change anything.


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Bret Williams
Re: Problem with fade to black of layered clips with white backgrounds
on May 7, 2014 at 1:22:30 pm

Just a guess, but your whites don't really match. They do to your eyes at a particular luminance level on your monitors, but as that luma comes down during the dissolve, it shows itself.

For example, 95 and 98 ire may look the same on a monitor not calibrated correctly or with the contrast cranked up. But once the luma lowers to something not as blown out, it becomes apparent.

In any case, you'll have to do what Jeremy says and either fade in black above the stack or compound and fade it out.


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David Meister
Re: Problem with fade to black of layered clips with white backgrounds
on May 7, 2014 at 2:42:23 pm

You're probably right in regards to white levels. But I can't seem to find a way to match really match the whites. Here's an export to illustrate what I mean: http://reels.creativecow.net/film/fade-to-black


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Jeremy Garchow
Re: Problem with fade to black of layered clips with white backgrounds
on May 7, 2014 at 4:11:29 pm

Thanks for the screen grab, it helps.

Nick's suggestion is right on. Luma Key to even out the white, then use a slug fade on top.

Jeremy


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Jeremy Garchow
Re: Problem with fade to black of layered clips with white backgrounds
on May 7, 2014 at 1:35:10 pm

Can you post a screen grab of the problem?


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Nikolas Bäurle
Re: Problem with fade to black of layered clips with white backgrounds
on May 7, 2014 at 2:31:42 pm

You need to put everything in a compound and fade the compound. If you dissolve each layer by itself you will have that problem. Same issue in FCP Legacy.

"Always look on the bright side of life" - Monty Python



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David Meister
Re: Problem with fade to black of layered clips with white backgrounds
on May 7, 2014 at 2:43:15 pm

I've tried that with no avail.


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Nick Toth
Re: Problem with fade to black of layered clips with white backgrounds
on May 7, 2014 at 2:49:24 pm

I have always had good luck dealing with this situation by using a luma key. In your case luma key the layer with the person. It doesn't have to be absolutely perfect. It is otherwise very difficult and sometimes impossible to match white shot with a camera to a generated white. Then use a black clip over everything for your fade as others have said.

anickt


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Bret Williams
Re: Problem with fade to black of layered clips with white backgrounds
on May 7, 2014 at 5:49:34 pm

Fwiw a black clip fading in above is the same as fading out a compound. Just usually more convenient.

As a test, what happens if you take the compound, and put a color effect on it and bring the overall luma way down? Do you see the difference in white levels now? With that still applied, or perhaps instead with your play head parked halfway through the dissolve, adjust the whites to match.

Use a waveform. You have been using a waveform to match them I assume. Try matching them at 95%. A white background doesn't need to be stark white unless it's matching a stark white web page or something.

I also like the luma key idea. Although you'd probably still see some of the same issue, but less.

Or, in case it's some weird FCP issue, try a fade to color effect instead of a dissolve.

If all else fails, I think the most aesthetic choice would be a cut. :) Or a push wipe, etc. something that doesn't fade. A white flash or fade to white, then fade to black.

Good luck.


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Petter Stahre
Re: Problem with fade to black of layered clips with white backgrounds
on May 7, 2014 at 7:28:55 pm
Last Edited By Petter Stahre on May 7, 2014 at 7:30:04 pm

I would just like to confirm that I guess I've run into the same problem, but I'm sorry to say I have yet to find a good solution.

A situation similar to what you describe can be repeated in FCPX by doing this:
– Create a clip containing a solid background (generator) 100% white (RGB 255,255,255).
– Make a copy of the clip, crop it or trim it and color it light grey (I used 90% white).
– You should now have a white background with a light grey rectangle somewhere.
– Mark them and make a compound clip (CC).
– Color correct the CC by changing the exposure so that the light grey rectangle disappears – all should seem to be white.
– Now good luck in trying to make a good transition using that CC :)

What I guess is happening is that the color values that FCPX is using internally for calculations can be over 255 (and under 0 I guess). Like a raw-image in Photoshop until you convert it.

So the two whites in the CC in my case becomes something like RGB 255,255,255 and RGB 280,280,280 which all displays as solid whites until you start to do calculations with them, then their actual color value is used – thus the difference during transitions.

Anyone awake? ;)

This is what the CC looks like in FCPX:


This is the CC when I apply an exposure correction (+11% overall):


And this is how the transition looks when I move the playhead:


Even if you create the transition using a separate clip above/under the CC the same happens.

It would be super if FCPX had some kind of limiter / clipping functionality that said all values under or over RGB 0 / 255 for this clip should be calculated as no less than 0 or no more than 255.

At least this is what I guess the problem is about but I would be very glad if I'm wrong and if there is a simple solution to this.


Best,
Petter


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Jeremy Garchow
Re: Problem with fade to black of layered clips with white backgrounds
on May 7, 2014 at 7:36:17 pm

A luma key fixes it.

Here's David's video with a luma key, new white BG, and slug fade:



http://reels.creativecow.net/film/luma


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Petter Stahre
Re: Problem with fade to black of layered clips with white backgrounds
on May 7, 2014 at 7:58:35 pm

Couldn't see the video (it starts/stops within 1 sec) but I think I get what you mean.

Thanks for the information, will try that next time!


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Jeremy Garchow
Re: Problem with fade to black of layered clips with white backgrounds
on May 7, 2014 at 8:01:34 pm

[Petter Stahre] "Couldn't see the video (it starts/stops within 1 sec) but I think I get what you mean."

I took the beginning of your movie, so it's short!

Here's a file of it: 7463_untitledproject.mp4.zip


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Petter Stahre
Re: Problem with fade to black of layered clips with white backgrounds
on May 7, 2014 at 8:25:22 pm

[Jeremy Garchow] "I took the beginning of your movie, so it's short!
"


Ah... not my video, but thank's for the effort.


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Jeremy Garchow
Re: Problem with fade to black of layered clips with white backgrounds
on May 7, 2014 at 8:40:08 pm

Oops, David's video.

Apologies.


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Nick Toth
Re: Problem with fade to black of layered clips with white backgrounds
on May 7, 2014 at 7:40:03 pm

Do the luma key. I've been doing it since the days of video switchers and tube cameras. The same idea carries forward into today's NLE's. Why make it difficult?

Also, you can't apply overall color correction to your white clips. You have to correct one white clip to match the other.

anickt


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Petter Stahre
Re: Problem with fade to black of layered clips with white backgrounds
on May 7, 2014 at 8:21:53 pm

[Nick Toth] "Do the luma key. I've been doing it since the days of video switchers and tube cameras. The same idea carries forward into today's NLE's. Why make it difficult?

And why stop making it easier? ;)
I understand the luma mask concept but think it could be much easier and less time consuming. A simple checkbox for the clip could do the job ("Clip values outside 0-255").

[Nick Toth] Also, you can't apply overall color correction to your white clips. You have to correct one white clip to match the other."

I made the situation up only to show that what seems matched on screen could still have different color values.

In my own case I noticed the problem when I was working with a movie clip and tried to get the over exposed whites become 5% grey. A luma mask would probably have been the solution.

Thanks for your input.


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David Meister
Re: Problem with fade to black of layered clips with white backgrounds
on May 8, 2014 at 9:10:25 am

Thank you all for your help. Luma key and fade with a slug on top works for me.

I agree with Petter, FCP X must have white levels beyond 255. Is there any point in having that? I know that you can go beyond 255 if you work in HDR 32 bits. Can FCP X do that? I know that in AE you can do some fun stuff by animating HDR material... Anyway, that's off thread. Thanks again. David


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