View Full Version : CC Correct Sequence? Gamma, Gain Offset
Chris Harding November 3rd, 2013, 09:50 PM Hi Guys
When using the Colour Corrector for exposure control (like a clip that has a bit of backlighting and the subject faces are a little under-exposed) is there a preferred sequence when setting the Gamma/Gain and Offset sliders???
Anyone have an answer? Do you set Gamma first, then adjust Gain and Offset or what is the best way to get the most out of the image?
Chris
Juris Lielpeteris November 3rd, 2013, 11:19 PM The best way is to monitor the process in the Videoscopes, in particular in Waveform monitor. Furthermore, I most often use Color curves instead of CC for similar activities.
Leslie Wand November 4th, 2013, 01:41 AM clc - curves > levels > colour
Richard Jones November 4th, 2013, 03:22 AM +1
Richard
Graham Bernard November 4th, 2013, 05:22 AM Simple, as you wish to raise the Shadows use CCurves and work those Graph Points. Using levels or anything that will have a global effect on your footage, will adjust boost everything!
I've stopped using 2ndColour Corrector about 5 years ago. There are other 3rd party plugs that are admirable. I now use GenArts ColorFast as my GoTo for lifting. It has the ability to shape the mask; keep skin tones safe or/and work with 3 levels of masking - Highlights and/or Midtones and/or Shadows to bring out the best in my exposure-challenged footage.
Colour corrections & grading is a passion with me.
Grazie
Chris Harding November 4th, 2013, 05:44 AM Thanks Guys
It only happens on very rare occasions when I'm fighting fierce backlighting and as already mentioned, levels simply boosts everything which doesn't really help lift stuff in the shade.
OK, with my simple mind and totally ignoring the colour wheels I can lift Gamma to get the level I want BUT I can also lift gain and get the same result and tweak either with offset. Vegas help doesn't tell you what effect each slider has on the image so if I have an image with a really blown out background but the faces of the subjects in the deep shade are still a little under-exposed, what is the best way to lift the underexposed part of the image ? This weekend my camera was already running at an EV of 2 stops over but the background was really really a killer so the faces in the shot are a bit crappy.
Thanks for all the suggestions ..the correct way to fix the problem (as minor as it is) would have been to crank the iris even more than two stops and let the background just totally blow out!!
Chris
Graham Bernard November 4th, 2013, 07:09 AM Thanks for all the suggestions ..the correct way to fix the problem (as minor as it is) would have been to crank the iris even more than two stops and let the background just totally blow out!! Well, yes. I've learnt to try and seek and eek out that sweet-spot of illumination versus blow-out. But that's our job - yeah? But sometimes, depending on the situ, you have to take your pragmatic view.
As a nod to working with what's there, I also use a matt box a rotated ND Grad filter. I can also use a reflector to illuminate the subject.
Grazie
Edward Troxel November 4th, 2013, 08:35 AM You might also want to take a look at the ColorFast plugin from NewBlue. It will let you control the darks, mids and highlights separately.
Seth Bloombaum November 4th, 2013, 10:53 AM ...so if I have an image with a really blown out background but the faces of the subjects in the deep shade are still a little under-exposed, what is the best way to lift the underexposed part of the image ?...
As mentioned above, color curves would typically be a first filter in this. Make sure you're modifying RGB (default), then add some points and draw the bottom of an S in the lower left area of the graph.
Waveform monitor will help inform you as to exactly what is going on with the various filter controls you're working with.
Chris Harding November 5th, 2013, 08:05 AM Thanks guys
I have this footage as best as I can get it but it is a pain when you get heavy back lighting in the background.
I see that Grazie uses reflectors to illuminate the subject..sheesh I never thought of that ! Is it effective without reflecting too much of the light behind the subject onto the front.
Peter Rush on the wedding forum has the same problem on an upcoming shoot with large bright windows behind the couple .... I did mention to him that Grazie talked about reflectors too here ... I would much rather reduce the problem before the shoot so post edit work is not so tricky!
Chris
Graham Bernard November 5th, 2013, 10:00 AM Chris? Hand over a still and I'll have a go.
G
Leslie Wand November 5th, 2013, 04:39 PM i always carry a couple of z96 led's and stands. amazing what they'll do to counter bright back light...
Chris Harding November 6th, 2013, 06:18 AM Hi Grazie
Here is a screen grab to play with ... as you can see the background is fairly blown out already and skins tones have gone crazy. What I normally do is add an Invert plugin followed by the CC and then another invert so I get my footage back to positive again. However I still tend to have to play via the scopes with gamma, gain and offset but never quite know if I should push gamma quite high and then add a little gain and adjust level with the offset or only push gamma a tiny bit and then add a fair amount of gain and correct with offset???
Thanks again guys for all the advice
Chris
Edward Troxel November 6th, 2013, 09:02 AM ColorFast can definitely correct this very quickly and easily. Sony Color Curves can also easily bring up the lows.
Graham Bernard November 6th, 2013, 12:24 PM Here's my take on it. The BG isn't doing much for the story anyway. So, I've gone for blowing the BG and concentrated on the foreground using ColorFast+Levels+Bump Map+Soft Contrast. Using a nice white background - some detail, but not the blokes with the rucksacks! - is this:-
Edward Troxel November 6th, 2013, 12:37 PM I did this with ColorFast:
Didn't want to "brighten" it too much but you can definitely see the faces now. Of course, you could easily go further and I actually lowered the brightness on the blown out background too.
Juris Lielpeteris November 6th, 2013, 12:46 PM The same with Sony Color curves:
Chris Harding November 6th, 2013, 07:18 PM Thanks Guys
ColourFast seems like a worthwhile plugin to get !
Chris
Graham Bernard November 7th, 2013, 12:14 PM Hi Chris, check out David McKnight's FAB NewBlue ColorFast Tutorial. Pure VooDoo.......
Video Tutorial: NewBlueFX ColorFast - YouTube
Chris Harding November 8th, 2013, 12:24 AM Thanks
Very informative but quite pricey at $129 just for a plugin I thought?
I'll have to give the trial version a run and then compare it with using Vegas only which still does a great job..it's only one ot two at most that give me the problem!!
Chris
Graham Bernard November 8th, 2013, 01:29 AM Very informative but quite pricey at $129 just for a plugin I thoughtWould you have paid $86.59? I did. How? I've signed up with New Blue and have them get me their news on OFFERS! I did this in Feb this year.
My Edit Day-Rate dictates I need swift results. I saw the ColorFast demo; had already signed up with NB, along with a mass of other 3rd party pluggers, to get in front of the offer train so when the CF offer came out - CardTime!
Plugs? It's what Vegas Pro has evolved into becoming capable of using. It wasn't always the case! Nu-uh . . . . . Consequently, not to take/make use of its 21st Century abilities is fighting with one hand tied behind your back all the time. However, I do understand. If you can get close to getting a result with Vegas then leave well alone and have more lenient delivery times go for it.
The "other" advantage of/with using 3rd Party plugs is a creative one: While I am thinking of the next scene or flow or movement, CF or any well constructed Plug will get me to it or have delivered what I want so I don't loose my train of thought or urgency with the main job of the editing process - hopefully making/creating engaging videos.
Cheers
Grazie
Graham Bernard November 8th, 2013, 02:32 AM Chris, do look at the following NB Tutorials for something along the lines of your needs explained in Colorfast.
ColorFast: Secondary Correction - YouTube
Justin Molush November 13th, 2013, 01:00 PM Just as a side-note, if you have access to AE, that can be used as a very advanced color correction tool as well. Check the attached image for a quick shot on my end done with native tools in a few minutes (Exposure, Levels, Curves, and Hue adjustment since the grooms face got very red after the initial curves boost).
Curves Shadow Boost -> Exposure Highlight Recovery -> Localized Subject Curves + Levels + Hue/Desat -> General Curves overall
The same procedure could be applied without running mattes as well, but you would have harsher background clipping as you wouldnt have that localized adjustment and the focus would be getting the front subjects up to par.
Juris Lielpeteris November 14th, 2013, 02:18 PM Justin, very nice result, but hard to build.
There Vegas + AAV ColorLab (http://aav6cc.blogspot.com/) (freeware):
Richard Jones November 15th, 2013, 04:54 AM Juris,
Would you like to explain how you did this please. I've had mixed results with AAV ColourLab and certainly nothing as good as this. Thank you.
Richard
Chris Harding November 15th, 2013, 06:53 AM Hi Richard
The one secret is to invert the image so it looks negative ..the CC works far better with the image inverted.
What you do is add a Sony Invert and push the slider to max ..then add you CC or AAV Plugin and finally add a second Sony Invert pushed to maximum so the image is inverted a second time and is correct.
In that order the CC is being applied to the inverted image where it does a lot better and then the corrected image (but still inverted) is then inverted back again to normal.
I found that trick on a lady called Eugenia's Vegas site!
Chris
Juris Lielpeteris November 15th, 2013, 10:49 AM Hi, Richard!
There is project of Vegas Pro 12
Image from here http://www.dvinfo.net/forum/what-happens-vegas/519770-cc-correct-sequence-gamma-gain-offset.html#post1819522
Richard Jones November 16th, 2013, 05:42 AM Hi Chris and thank you. I'll give that a go although, for me, the Vegas adjustments can often be applied straight without inversion but this looks a useful trick to have in the bag.
My real problems come with the AAV Plug In which I seem to have more difficulty with. Which link are you referring to on this page Juris? I don't seem to be able to open your zip file either as Vegas Pro 12 can't find it..
Thank you.
Richard.
Juris Lielpeteris November 16th, 2013, 08:28 AM The first piture by Chris Harding, attachment in #13, named backlight.jpg.
David Johns November 23rd, 2013, 12:27 PM I couldn't resist having a go, more out of curiosity than of any claim to be good at it...
Both attempts done in Vegas Pro 12 using its built-in colour curves etc
First one is Colour Corrector + Colour Curves (twice) plus a mask
Second one is just plain ol' Vegas Fill Light
Graham Bernard November 23rd, 2013, 12:38 PM Very nice David.
G
Juris Lielpeteris November 23rd, 2013, 03:53 PM Second one is just plain ol' Vegas Fill Light
Exelent, David!
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