Cineform and Colorimetry

[Alex Raskin]

I'm shooting Cineform RAW (SI2K cam).

At the beginning of each scene, I shoot the Test Chart

The idea is to have a solid reference for both colors, and white/gray/black points so to adjust the video in post to match the reference chart (if we want natural look without effects, that is).

What are the practical steps to do so, though?

Is there a way to do this in FirstLight?

I'd love to create a LUT that can then be applied to all video clips from this same scene so they all would be color-corrected uniformly as they should. How?

[David Newman]

Possible. Most just eye match, and leave the LUT for creative. You can use the LUT for matching, but the tool to help with this is part of the upcoming V5.0. If you follow me on twitter I released a beta of GenLook.exe tool about a 10-days ago. Look for "This week in cool hacks:"

David Newman (David_Newman) on Twitter

[Jay Bloomfield]

Whoa! That's pretty useful. I can't wait for Neo 5 to see what other "goodies" you have in store for us.

You might want to consider including another command line option to automatically register the LUT with FL.

[Alex Raskin]

Originally Posted by David Newman

If you follow me on twitter...

I'm trying. But Phil Bloom's rapid-fire tweets block the view sometimes ;)

[David Newman]

Jay,

No need. Double click on the .look files and they automatically register.

[Jay Bloomfield]

I know that, but I'm lazy. ;-)

[Alex Raskin]

+1 on auto-registering .look files, please.

Naturally one would think that if a .look is created and saved, then system would see it... but now it's not so - an extra step is involved in locating each .new look file in Explorer and double-clicking on each to register.

Looks like auto-registration would be natural, and would improve workflow.

[Jay Bloomfield]

It seems like you could do it with a Windows BAT file. Just pass the BAT file command line arguments to GenLook.exe in the first line of the BAT file and then have the next line be LookInstaller and the output .look file name argument (or just the .look file itself, since it's associated with LookInstaller.exe). Or something like that.

usage: GenLooknLoad <fileA.bmp|dpx> <fileB.bmp|dpx> <fileout.look> [-sLUT_Size]

c:\...\GenLook %1 %2 %3 %4
<error handling for bad, missing args>
%3 <or c:\...\LookInstaller %3>

[Henry Olonga]

Hi guys - I find this genlook.exe very interesting.

Here is a thought so - say I want to give my footage the look of my Sigma SD14 foveon camera. It has a very specific look. Can I say get a colour chart scan it - then shoot that on the sigma and then using genlook extract a look from the differences between the two - is that my understanding?

By the way - how do we use genlook.exe - is it integrated into firstlight?I am not a computer wiz so I haven't a clue - double clicking on it does nothing apart from bring up a DOS window for a split second.

Jay - is that all done in a DOS window ?

[David Newman]

Henry,

Sorry you have to use a shell (command prompt) to run this utility. However it doesn't do quite what you are suggesting as it requires pixel for pixel alignment to model how colors map from one look to another. So it doesn't match cameras, rather it is for creative look design in any tool you are comfortable with.

[Henry Olonga]

Thanks David,
Okay - say I shoot a chart with it and then have a flat image. And then I boost saturation and add contrast to that image - would that work in getting a LUT?

So if I have image A and I have image B. Could you give me the command prompt to extract a lut out of this program?Excuse my illiteracy

[David Newman]

Firstly, what you describe is the sort of thing FirstLight does fine without LUTs. This GenLook tool is designed for creating different image looks that FL doesn't directly support within it base controls (like color keyed secondaries.)

Technique 1

1) Save your source to DPX or BMP.
2) Color corrected in whatever tool and save to final destination DPX or BMP (same as source.)
3) WindowsKey+R, type "CMD" to bring up a shell.
4) at the prompt>: genlook your_path_to/source.dpx your_path_to/destination.dpx newlook.look
e.g.
> GenLook v:\myclips\frame50.bmp v:\myclips\frame50tweaked.bmp v:\LUT\MySepia.look
5) Double click on v:\LUT\MySepia.look


Technique 2 (can be better quality and more accurate )

1) Save your source to DPX or BMP.
2) WindowsKey+R, type "CMD" to bring up a shell.
3) at the prompt: genlook your_path_to/source.dpx your_path_to/genmap.dpx
e.g.
> GenLook v:\myclips\frame50.dpx v:\myclips\genmap.dpx
Note: genmap.dpx is the output.
4) Color correct (frame50.dpx) in whatever tool to prefer.
5) replace to source with genmap.dpx but using the same correction parameters, save this as dest.dpx.
6) WindowsKey+R type "CMD"
7) at the prompt: genlook your_path_to/source.dpx your_path_to/dest.dpx newlook.look
e.g.
> GenLook v:\myclips\genmap.dpx v:\myclips\dest.dpx v:\LUT\newlook.look
8) Double click on newlook.look

[Henry Olonga]

Thank you David - much appreciated.By the way - you are an Aussie right?All your videos make it sound like you are.Best wishes. Henry

[David Newman]

Yep, an Aussie, but many Americans think I from your neck of the woods. I have planned to do a video on using GenLook also. Need a list of all the video to do.

[Henry Olonga]

Hey David - it works!!!! This opens up a few possibilities I must say. So now I have speedgrade and this technique to create looks.

By the way - my better half is from Adelaide.I have to say I am blown away at your company's innovation and dedication.Keep it up guys!!!