[Toby Tomkins]

That’s a fair point, you could use redlogfilm LUTs, look at AntlerPost LUTs.

[Toby Tomkins]

Try this Francesco: https://www.motionfx.gr/generic-lut.html

[Toby Tomkins]

We’re both saying some of the same things Mike, and I totally agree about the film matrix option.

Francesco, experiment until you find something you like. Like I said before, there’s no right or wrong way to process your log files when going to Rec709, if it looks good to you, it works (-;

Mike, I’m sorry if I offended you, I’m only sharing what I’ve read.

Sadly you can’t ‘correctly’ use the arri lut builder with ‘film matrix on’ material, so this whole discussion is a bit of a moot point actually. Arri expects you to have your own pipeline for film material and your own LogC to Rec709 LUT. So you will need to find a generic Cineon to Rec709 LUT after all.

[Toby Tomkins]

The matrix is applied during recording, to emulate film, so the alexa logc rushes are comparable to film scans. It lets you use traditional film print LUTs and mix the alexa material with arrilaser film scans. As such, if using an alexa LUT for actual film scans, you would be better off using a LUT based around the matrix setting being on.

[Toby Tomkins]

I think you want film matrix on (or configure the lut in the arri lut builder as if film matrix was on during recording of an Alexa log image)…Think of it like this, if you want to have an Alexa log image similar to a film scan, you would record with film matrix on, as specified on the arri website;

“Log C (film matrix on) applies a color matrix that makes the resulting image resemble a film negative scanned on an ARRISCAN. While this option somewhat reduces the color gamut in contrast to Log C (film matrix off), it provides an easy and fast way for colorists who are used to scanned negative, thus speeding up color grading. It is also a great option when combining ALEXA images with film originated images. The same caveats as for Log C (film matrix off) also apply.”

Also from what I understand LogC is the same as cineon, here’s a brief history I found;

“LogC stands for Cineon Log and is not an ARRI invention it is a Kodak invention created to be able to capture film scans across a wide dynamic range.

https://en.wikipedia.org/wiki/Cineon (https://en.wikipedia.org/wiki/Cineon)

And

“Arri adopted the use of the Cineon specification as a means of encoding image data in a log format for the ARRISCAN film scanner. This was implemented to properly allow the digital representation of the dynamic range that film delivers in a 10 bit logarithmic file format where each stop of exposure is mapped in equal intervals of digital code values, thereby creating a digital negative. The Cineon Format was developed by Kodak in the mid 90’s for use in the Cineon Fim Scanner. ARRI adopted it for use in the ARRILaser ARRIScanner, D20/D21, and the Alexa.

Therefore the name LogC is essentially an abbreviation of Logarithm and Cineon referring to the way ARRI has chosen to implement it’s log encoding of image data in the Cineon Format Specification and the corresponding characteristic curve. Just like SLog is Log encoding based on Sony’s implementation of log in order to optimize their camera’s output; and LogF is Log encoding based on the Filmstream format for the same reason. They are all characteristic curves developed to take advantage of the technology inherent in the camera systems that they come from. You can think of it in the same way that different film stocks offer different characteristic curves and therefore offer more or less dynamic range and tonality then other film stocks.

Truth is there’s no perfect way to ‘linearise’ your files (FYI that term can mean many things), technically you could go to a scene referred colour spaces and then use an ODT for a given colourspace, but you’d still need an RRT which is subjective in itself. Experiment with curves (make them smooth!) and different LUTs and find what works best for this project. There is no one size fits all. You were ‘limited’ with film print LUTs before, where you had to grade in front of that LUT (so you could stay in log to deliver log files for the film print), but now if you’re delivering in rec709, you’re not finishing in log, so do what you want as long as it looks good.

From the sounds of it you’re in need of a colourist with their own suite. There’s plenty out there. Make a friend. Collaborate.

Toby

[Toby Tomkins]

Try using an Alexa log c (important: film matrix ON) to rec709 LUT and grade before it (either load the LUT as the final node in a chain or load it as a node in track mode). This should get you nice results. LogC is the same as cineon log which is probably what your scans are.

I’m shooting my own tests on 10 35mm film stocks and 4 digital cinema cameras (Alexa, red, f65, c500). Off the back of that I’m creating various LUTs, some of which you might find useful. Let me know if you’re interested and I’ll keep you posted.

Toby

[Toby Tomkins]

Select all the clips in the timeline in theChris is cooking a meal. Peeps coming over here. Color page and drag a saved memory to the timeline.

[Toby Tomkins]

4gb 680 is the best I believe.

[Toby Tomkins]

Thank you Rafael, I have emailed you.

FYI Scott the download links on the apple links you sent haven’t worked for a while )-:

Thanks guys,

[Toby Tomkins]

Also the same monitor?

What OS’s are on the macs?