Finally all render/compositing jobs are done and I have now the full 1080p footage ready.
I still do have the intermediate multilayer renderpasses for each shot, in case there is the need to revisit some compositing tasks. The storage demand is quite huge for these (a single frame typically has ~140MB) , but it already saved me a lot of time and trouble. I guess I will only delete them once the movie is eventually released 🙂
The compositing pass creates the final frames which are delivered as OpenEXR files. Here we typically have 23 MB per frame.
I did some intense testing and exploring on how to best tackle the color grading workflow. As I now did a very close look to the whole color behaviour, I noticed that initially I had wrongly calibrated my monitor and had done the primary color grading in the compositing on a display with a gamma setting of 2.4. That means, that on a correctly calibrated display, the movie displays too bright and flat.
My initial idea was to apply the appropriate gamma correction in blender, but as already mentioned in my previous post, I decided to try out DaVinci Resolve Lite. The new problem that this did create, was that I had to switch to Windows to work with this software. That in itself wouldn’t be a big problem, but I soon found out that the display driver under Windows acts quite differently to the one under Linux. In fact I didn’t manage, to get the same color dynamic under both OSes. I got the gamma setting ok, but for the white and black point I had absolutely no chance to get it to work correctly under Windows. The solution would be of course do buy a real hardware calibration tool, but that is not an option right now and I have to find an other way.
This different behaviour made me a bit uneasy and I did numerous tests on both platforms to learn how these differences show in the final color grading. That was when I learned that my monitor has a gamma drift over time. When freshly turned on, I need a correction of 1.20 and after 4-5 hrs I am down to 1.05.
What I do now, is to constantly check the actual gamma value ( using the cool test images at http://www.lagom.nl/lcd-test/) and apply a correction if necessary. Its a bit tedious, but with this I get relatively reproducible results.
What got me a bit frustrated were the tests I did on my 40″ FulHD TV. It provides a load of settings, none of which seems to have anything to do with a gamma 2.2 setting … Most settings have blown out highlights or oversharpening. The 100Hz feature destroys completely the movie feeling. I really wonder how this movie will look like on the various displays when eventually released. This is something that is completely out of my control.
Anyway, for all those interested, I have a 2 shot sequence in 1080p for you to download and look at. I would really be interested how this sequence looks like on your individual display. With a correct gamma 2.2 display, you should see a relatively dark movie with stark contrast, but there is no completely black area. You should still be able to see features even in the darkest spots. But these dark spots should really be dark and not misty white washed. Please have a look and tell me how your viewing experience is and what display settings you have.