Grading something someone else shot. Personally I would NEVER have shot Slog 2 at night/low light - Hyper Gamma 7 or REC 709 is far more appropriate than this bright highlight handling gamma type...
Looks like this:
So it gets a Slog2 to 709 LUT in source bin which makes it as noisy as VHS and does crazy things to the whites (look at the purple whites under his cap):
So I delete the LUT and just go full manual and the colour casts and crazy noisy colours go:
Bin metadata says capture ganmme equation is "user defined curve 9"; cameraman says its Slog2.
Am I doing anything wrong here guys, workflow wise?
Thanks for any help
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LUTs are a mine field.
I just did a job from Sony cameras that the DP said was SLOG2 (+ one of the variants). There were three camera.
When I AMA linked in MC 8.10, Avid chose a different LUT for each. And none looked that good.
The DP had provided a Sony LUT that he liked. So I loaded that LUT into Avid (dig through the doc on how to) and assigned this to all 3 cameras. Much better - they all matched now. Was the color perfect? Not really.
Moral? Avid's LUTs may not be the best / most up to date. Check the camera makers support.
My experience has been the best camera / Avid LUT combo I have gotten is Arri Alexa / Amira. That is generally very nice.
In my experience, shooting any form of LOG really means you are headed for a supervised color correction session. A LUT gets you in the neighborhood.
Plus LUTs, by their nature, can and will permanetly clip some levels. You can work around this by getting rid of the Source assigned LUT and putting a color correction on the clip and then adding a LUT. This is pretty common.
But the real color correction systems (Baselight and Resolve for example) have moved to what can be called Color Transforms. They provide the basics of a LUT but have no level clipping. As a result they most likely will need more correction afterwards.
All that said, many colorist prefer to balance LOG material with no LUT, just working with the scene. That requires skill.
My 2 cents.
Jef
_____________________________________________
Jef Huey
Senior Editor
Thanks Jef. I too have concluded that grading with no source LUT is beyond better - I had to strip it all off and start again - have far better results now. Symphony's auto balance tools for contrast and then colour get you in teh ballpark and then I fix gamma and white balance and then black balance. What a PITA for bread and butter stuff! ;)
I dont understand why it fails though - the LUT is meant to equal but opposite the Slog gamm and colourspace and make it normal and ballpark OK. But it doesnt - it hammers it to death and creates all sorts of colour casts and issues. I wonder why?
DIESELE: I dont understand why it fails though - the LUT is meant to equal but opposite the Slog gamm and colourspace and make it normal and ballpark OK. But it doesnt - it hammers it to death and creates all sorts of colour casts and issues. I wonder why?
In my experience, that means you just do not have the correct LUT. See my comment about Avid provided SLOG LUT vs. DP / Sony provided LUT.
M
jef:In my experience, that means you just do not have the correct LUT.
I agree. And finding the correct LUT in this case can be very difficult.
When the camera (was it FS7?) is in CineEI mode the output is well defined. But when the camera is in custom mode a lot of settings can be ajusted. The gamma/log curve can be set to s-log2 but that does not tell anything about the color. I think there are seveni color matrix presets to chose from - each requiring a different LUT. It’s even possible to tweak the color matrix settings in the camera - in that case a custom LUT would be needed.
In my opinion it’s not really a shortcoming in Media Composer. Have you asked the camera man if he has a LUT that matches his actual camera settings?
Kåre Nejmann
Danish Broadcasting Corporation - DRAarhus, Denmark
How do you verify what LUT you need then Jef - I even asked the cameraman and he said Slog2, as written on the drive...
The bin gamma metadata said "user defined curve 9" which implies that he has tweaked the Slog? Or shouldnt I expect that metadata through and to state Slog2? I know i get my HyperGamma metadata through no problem in the bins for what I shoot. Confusing stuff!
DIESELE: How do you verify what LUT you need then Jef - I even asked the cameraman and he said Slog2, as written on the drive... The bin gamma metadata said "user defined curve 9" which implies that he has tweaked the Slog? Or shouldnt I expect that metadata through and to state Slog2? I know i get my HyperGamma metadata through no problem in the bins for what I shoot. Confusing stuff!
I wish I knew.
Luckily in my case the DP was very specific in which settings he used and with the LUT he provided. As Kåre Nejmann above noted, you are really at th mercy of the DP when so many settings are available.
As an accredited TV cameraman I just dont get why you would supply weird custom stuff for bread and butter TV! You'd become known as the cameraman that supplies difficult material that costs money to grade and cant be done in Avid easily! I doubt this cameraperson would have tweaked deep in-camera settings as they shot Slog2 at night...under... Enough said.
Can anyone say a positive about Slog for midrange TV stuff now please ;)
Out of curiousity, have you tried applying the SLOG2 LUT in the free Resolve and seeing what it looks like there?
And have you taken a look at the following?
https://pro.sony/s3/cms-static-content/uploadfile/99/1237494271399.pdf
DIESELE:How do you verify what LUT you need then Jef - I even asked the cameraman and he said Slog2, as written on the drive...
I just read elsewhere ... Use the Sony Cataylst software to inspect the camera files. It may give you the info you need.
Just recently, some blackmagic ursa luts that i downloaded were looking horrible.
I opened up resolve and I liked the built in luts they have.
You can import blackmagics luts into Media Composer
Go to the proejct settings in resolve and you can open your luts folder to see where they're at.
i trust the creators of resolve when it comes to LUTs. But obviously, luts are never perfect, they just get you closer to where you want to be if you choose the right one.
Try it out, i look forward to hear if it helped.
Hello,you need to realize that the Luts are only auxiliary gears for quick sorting. If the material I supply to the Baseligt colorist, it requires a raw log without Luts. Lut do not use and create a custom correction.Log materials should be used if full color corrections are included in the postproduction process (Beselight, DaVici Resolve ...)
MC is not a suitable LOG material coloring tool.
V.
Symphony is very good at Color Correction.
Even if you don't use LUTs you can control Shadows Midtones and Highlights and the Contrast and Saturation etc of those values perfectly.
LUTs and CC are not magical things, they are based on the shot material, the footage.
At my GH5 (using Log in it gives you a DR of 12 stops) I start with Panasonic Vlog to 709 LUT and go on from there.
But what's important is to shoot with correct f/stop and most of all for LUT correction, right WB.
And of course the DR of the camera itself.
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Sinfono - I agree George.
Further research indicates that you should not really use a LUT prior to grading in Avid - (you probably keep it tighter - well you do when you also edit and grade what you expose... :-) ) as using one may well clip the whites or crush the blacks and you can no longer recover these AFTER the LUT. Plus my Slog2 to 709 LUT destroyed many of the images - especially if exposure wasnt very well handled on many shots like I had (not my shoot)...
What worked for me - and thanks to all for their tips - was remove LUT, then auto contrast to set peak white and black. Then auto colour and then dial it in manually by eye from there. Results were OK if fiddly as I had to do many black balances and many other tweaks that I hever have to do using Hyper Gamma 4 (which has almost the same dynamic range as Slog) - not a slog fan really LOL!
Interestingly the shots all looked OK in Sony Catalyst Browser with the Sony LUT - Avids one just didnt work for me.
Of course this will be the case if there is no right exposure.
LUT is a Color Correction preset itself so it's logical if those values are not kept by using a shooting LUT (on camera) of the same editing LUT, you are in trouble.
In this case I would also manually Color Correct.
But for me then there is no point of using a LUT because you are not applying the LUT.
Also I have seen that in V-Log or other Logs (keeping the camera image as seen by the sensor without any in camera modification) it's better not using Auto modes in Symphony but to work manually.
While in other cases Auto works fine in Log one should not use it and for the WB is better using the picker.
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