[Tig] need info on creating a lut from scratch , from a linear image

[TSassoon at aol.com]

In a message dated 9/8/06 5:41:40 AM, patrice at hybride.com writes:

> what are the specification to have a linear image re-map to log and that 
> the person that is doing the printing is going to have all the range of the 
> image
> 


Easy way with commonly available software: in Adobe After Effects 7, import 
footage, make comp from it, apply Effect->Utility->Cineon Converter, and change 
the transform popup to "Linear to Log" (default is log to lin). Also go File->
Scripts->DemoPalette.jsx, and click on Cineon Adjust. That will make a 
non-rendering linear print density preview. Adjust the white point particularly of 
the Cineon Converter effect on the image layer, and be sure that the gamma 
transform is the same as monitor gamma (or that it looks good to you, whichever). 
Render out to Cineon files preferably, using the Full Range preset. Cineon 
files (not DPX) will reduce confusion with the film recorder. Oh, and BTW, make 
sure it's rendering at 16bpc at least.

It's not a bad idea to set the output ("10-bit white point") white point 
above the 685 90% white level so that the highlights burn in nicely, maybe to 730 
or so. Especially for burn-in text, so it doesn't go muddy on a dark print.


Tim Sassoon
SFD vfx & creative post
Santa Monica, CA