Brighten Dark Faces (part two ...)

johnmeyer wrote on 2/13/2012, 4:18 PM
This same issue was discussed just a few weeks ago:

how to gain lights to this video in post prod

The problem was how to make the faces of dancers on a stage brighter without affecting the rest of the video.

In that thread, I suggested using the Vegas Color Curves tool, and offered an example. However, at the end of that thread, LoTN suggested the following intriguing idea:

"using a duplicated track composited in dodge mode. The upper track is reversed with a curve and get adjusted with secondary CC. Composite level set to 85%."

Well, it turns out someone gave me some dance video captured with an iTouch that was shot against a bright backdrop. So, I've now got almost the same problem. I tried my color curves, but wasn't totally satisfied. As a result, I went back and read what I copied above, and then re-read it a dozen times.

I would like anyone out there that has done this to look at the following and see if I am doing the right thing. Also, if there is a tutorial or anything else on this, I'd like to read it.

I started by duplicating the video track.



I then added a secondary color corrector to the event on the top track and then selected just the color of a person's face. I then adjusted the Secondary CC mask so it was very generous at what was included: I would rather gain a few unwanted areas than leave portions of a person's face dark.

I then added the following color curve. I am hoping that someone can comment on this and tell me if it is the correct thing to be doing. If it is, I rather like this approach because it lets me "bump" only a range of luma values, and only if they meet the criteria set by the secondary color corrector.



To actually get the whole thing to work, I then set the upper track composite mode to "dodge." The strength of the effect can be reduced, if necessary, by reducing the Opacity of the event on the upper track. I suppose this could be further refined by keyframing with a track composite envelope.

Here is the "Before" image, followed by the results using just a simple Color Curves correction. The last image is the result using the technique described above. The detail in the video is lacking because, even though the iTouch takes video at 1280x720, at low light, it is not a great video camera.

Comments or suggestions??


Original


Color Curves


Dodge Composite Technique

Comments

farss wrote on 2/13/2012, 5:28 PM
John,
for what it's worth I've done something similar, use the Secondary CC tool to select based on luma and chroma, futz with the mask softness and then use a curve or just use the gamma adjustment in the Secondary CC FX.

The problem I always run up against is there's only so much you can do and it's quite easy to make things look worse. I've easily enough run into problems with banding / solarization and ugly noise. Quite oftenly after spending a fair slab of time futzing around I go back to the original and reach the conclusion it might be better to just leave it alone.

The Dodge method does look better than the CC method, there's less loss of detail in the face, most noticeable on the middle dancers face so that's a plus. At the same time to my eye the skin looks very plastic but we're only looking at one frame so my perception may change when we see the dancers moving. Also I suspect you're going to have to spend a lot of time keyframing, there appears to be some very bright spots just in front of the dancers and I imagine from time to time they're going to get hit by them and could well suffer from the exact opposite problem of being over exposed.

Bob.
johnmeyer wrote on 2/13/2012, 5:59 PM
Bob,

Thanks for that critique. The "plastic" look is mostly due to the nature of the yucky iThingy video. Once the lack of details are "brought to light" by gaining the shadows, this defect in the video itself becomes more apparent. However, with the settings I used, the center dancer's face is definitely on the edge of being solarized. So, your comments about keyframing are definitely correct. On the other hand, the two dancers on either end look much better than with the straightforward color curves approach.

I'm also having "fun" with this project discovering all the horrors of a really bad CMOS video: jello and wobble distortion everywhere. I'm finding that my purchased version of Mercalli, with the CMOS correction enabled helps to not only stabilize the footage but in some cases (certainly not all) reduce the impact of this nightmarish artifact. Whoever designed the cameras that use CMOS sensors this way should have to go back to school. It is obviously possible to create CMOS cameras that have this artifact mostly suppressed.

Ooops, I just took my own thread OT.

Tech Diver wrote on 2/13/2012, 10:14 PM
John,

I played around with your image from your post using a slighly different approach. First, I duplicated your image on a second track. On the upper track I applied the "Chroma Key" filter and sampled the face of the middle dancer (R=106, G=55, B=35). I kept the low threshold at 0.000 and the high threshold at around 0.390 . Then on the lower track, I applied the "Brightness and Contrast" filter, setting the brightness to 0.15 . I feel this works rather well, but you have to be the final judge. Unfortunately, I do not have a Photobucket or similar account where I can post the results, but you should be able to duplicate my efforts with ease.

Peter
johnmeyer wrote on 2/13/2012, 10:23 PM
Interesting idea of using the Chroma Keyer for the mask generator rather than the Secondary CC. I was able to get it to work, although I didn't feel I had as much control over the mask as what I was able to get with the Secondary CC controls. As a result, I ended up gaining the background walls too much. On the other hand, this was easier.

So, thanks for giving me another "tool" to use.
farss wrote on 2/13/2012, 10:43 PM
Thsi thread is timely :(
I've got to shoot the mother of all backlit scenes in a few days.
Straight into the sun rising over the ocean as the talent goes in / out of the ocean. No I don't have the crew to bring along a 12K that I might be able to borrow so it'll be just a reflector to try to balance the sun against the talent. This will be the opening "money" shot. Wish me luck and how much is a replacment block for an EX1?

Bob.
Marc S wrote on 2/14/2012, 1:34 AM
You may want to try out Magic Bullet Looks. You can add multiple spot exposures.
Grazie wrote on 2/14/2012, 2:35 AM
I too have success using Chroma Keying plus a little Invert. I avoid 2nd Colour Corrector for masking, applied to movement, like the plague. As a camera pans and Scans major aberrations start to twinkle on screen.

OK, this doesn't directly answer your question, but IF having the need to have the faces "correctly" illuminated can't be got over, I really do think you're on a hiding to nothing here, in which case I'd go straight to an impressionist view, and support the narrative that way.

Once on that track, there is much to be done. Oh yes . . .

From what I can make out there is a lot of saturation going on in the background. The Dancers and the movement ARE the thing - faces or not. I went straight to Black and White and started to bring back the Chroma.

I've also had a modicum of success just using our old friend "Levels". But, what ever you do, you wont be happy with it. White Flag time! And maybe making something "other" with it. Looks like Spanish "Flamenco" Dancing? - Go with a contrasty thing, Black and White and you may even want to splash on some Soft Contrast.

And to echo the other post here, we're getting awfully close to MBLs!

What exactly IS your mission here? Are you needing to supply this to a demanding client? Have they asked for the faces to pop?

Anyway, this has been a neat opportunity to flex my Creative Muscles. Thanks for the opportunity John.

Cheers

G

Rory Cooper wrote on 2/14/2012, 5:32 AM
Compositing = lighten would be better than dodge as it would only composite the lumens onto your existing duplicate and you can drop levels for overexposure same as dodge but then you have a problem as soon as you add color curves you would have to dump gamma so it defeats the object same as dodge.

The best bet would still be an old fashioned garbage mask with secondary color corrector as you have maximum control over range of lumens, saturation and hue independently of each other.
farss wrote on 2/14/2012, 6:38 AM
If you had Resolve an oval mask per face linked to trackers would be the go.
Unfortunately from what I read the free version of Resolve limits the number of nodes so the "power window" thing is out.

Grazie has raised a very good set of points, why is anything being done at all?
I do a bit of work for a choreographer and oh boy, you really have to watch your step with the serious full on "arts" people. "No Bob, I do NOT want a dance video, I want a video of MY dance." I actually got her into trouble at one workshop because I "was a professional" and that was not at all in the spirit of things.

Here's one of her works from a while ago that she shot herself. Looks similar. My offer to "fix" it wasn't that well received:



Bob.
JJKizak wrote on 2/14/2012, 6:50 AM
Maybe you have to be more dramatic in your evaluation of their dance video---tell them "it looks like shit".
JJK
johnmeyer wrote on 2/14/2012, 10:55 AM
Fortunately this is not for a demanding client, and they will be very, very happy with the improvements.

In the end, I went back to using a simple Color Curves low-mid luma correction. Like so many other restoration techniques I try, the improvements from the more exotic approaches often introduce artifacts that don't show up in a short test clip, but then pop up here and there under different circumstances. If I had the time to adjust and track every section of this thirty-minute video, I would definitely use one of the masking/luma bump techniques discussed above. However, I don't have the time to watch every frame and look for little "gotchas" that pop up. The color curves correction has no surprises.

Thanks for all the help and suggestions!
PeterDuke wrote on 2/14/2012, 5:03 PM
Does the Shadow/Highlights effect in Adobe Prem Pro, Prem Elements or After Effects do anything useful for you?
johnmeyer wrote on 2/14/2012, 5:21 PM
Does the Shadow/Highlights effect in Adobe Prem Pro, Prem Elements or After Effects do anything useful for you?I don't own any of those products (or any Adobe products, for that matter), so I'm afraid I can't answer that.
farss wrote on 2/14/2012, 5:34 PM
"Maybe you have to be more dramatic in your evaluation of their dance video---tell them "it looks like ****". "

It sure does, no question about that. The dancers might be pathetic as well I wouldn't know. Neither matter because it isn't about any of that. It is about the choreography.

When I've shot for her she fully understands that I want the footage to look as good as it can. I am a crafts person just like the people who dance for her, she respects that and will make quite an effort to assist that outcome. If I went to her and asked her to choreograph a dance routine for a music video the whole relationship and the flow of creativity reverses. If I wanted to make a dance video then I employ a composer, a choreographer, dancers, musicians etc. Then it is MY dance video.

Bob.