Color grading the F35

mlysbakken

mlysbakken

Well-known member
Hi,
There's quite a lot of information about LUT's, IDT's and ACES in the main thread, but for those who don't feel like sifting through 180+ pages, I thought I'd make a separate thread.

LUT's:
The most relevant info for most of us is probably regarding LUT's. There has been presented at least three different solutions:
1) An "s-log to rec.709" LUT, made by macgregor. This is based on the s-log whitepaper, so it's technically accurate, but it doesn't automatically apply the most "filmic" look. https://dl.dropbox.com/u/13362047/slog macgregor_12.cube
2) An "s-log to cineon" ICT as input transform, with a "cineon to desired filmstock" LUT on the other end, again made by macgregor. https://dl.dropboxusercontent.com/u/13362047/F35 slog to cineon.zip
3) A direct "s-log to film print" LUT. The fastest way of getting good results, but it isn't for free.

Color space:
The color space you interpret your footage in has a huge impact on the results and limitations of your grade. Currently there is no s-gamut support in any application I know, but macgregor experienced a huge improvement by going from the default sRGB interpretation to AdobeRGB. However, this is not an option in DaVinci Resolve. Perhaps somehow we could make a new color profile for s-gamut. If not, there's one last solution to get the most out of the image:

ACES:
Now here's my personal contribution to the ongoing exploration: the Sony F35 IDT for grading in ACES. https://www.dropbox.com/s/rfg680j7d0mfdw7/ACES_ODT_IDT.zip
The IDT is used to convert the log/raw of a specific camera into a common 16 bit color space where no data is lost. Afterwards an ODT is used to bring it back to the color space of the desired viewing medium. The result is much better gradations and richer colors. In short: more control. However, I've heard there are some limitations to IDT implementation in Resolve Lite. I haven't had the time to test it yet, though.

If you're keen to test out F35 grading in ACES in an NLE, there's support for it in Sony Vegas, as explained here: http://dspcdn.sonycreativesoftware.com/whitepapers/vegaspro12_s-log_and_aces_workflow.pdf
Macgregor has also showcased some F35 footage graded in Vegas here: http://www.dvxuser.com/V6/showthread.php?293726-Slog-color-management-in-Vegas-12
 
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Thanks for breaking this thread out. And thanks for finding the IDT- been wanting that but didn't know who to ask.

I tried getting the F35 IDT into Resolve 10 Lite last night. Sadly, no luck. :(

Before I upgrade to the full version of Resolve I'd like to hear if somebody with the full version is able to get the IDT/ODTs imported.
 
We could perhaps contact Blackmagic and ask them to add support for it. Seeing as the lite version already has alexa and red built in, it makes no sense from a business standpoint to limit F35 support.
 
Over the last 8 months I've come to the conclusion (right or wrong) that there's no single best method for grading the sLog footage from the F35. It all depends on what you want to accomplish, what look you're after, etc.. Lately I've been feeling a bit hemmed in by the three or four cineon-to-filmstock output LUTS, so I've been skipping using any input/output LUTS in the Resolve project settings and just using the final node in the grade to apply a LUT. The film look LUTs that ship with Resolve are decent, but lately I've found that my go-to choice is the Arri Alexa LogC to Rec709 3d LUT. It has a nice tonality to the blacks. It does tend to push the exposure & saturation a bit hot, though, so I put serial nodes in the grade to correct for those. My basic F35 sLog grade has the main slog node, a white balance adjustment node, an exposure adjustment node, a saturation adjustment node and a LUT node. If I need to pull secondaries I insert a node before the LUT node to do those operations.

Here's an example using one of my many silly low-light tests:

sLog from the camera...
slog.JPG

Grade node flow...
nodes.JPG

Graded result (using the Arri LUT with node mods for WB, exp & sat)...
graded.JPG

But, as mentioned, there are many ways to skin this cat. This is just one way of doing it. I'm sure that a high end pro colorist or pixel peeper could rattle off a grocery list of issues with this approach (and I'd gladly learn from them if they did), but for the stuff I'm doing it works for me. YMMV.

-k

ps: you don't need to use a separate node for each operation. I just do that so I can keep track of what I'm doing more easily.
 
Do you guys think it'd be possible to get the Filmconvert people to make a profile for the F35? I love what that plugin does to other cameras, and I'd love to have it available for the F35...
 
Give the Filmconvert BMC log profile a go, with a few very slight tweaks I got some delightful results on SLOG from the F3.
 
I've been messing a bit with the Filmconvert demo plug in. Not bad. It's a bit hot on the noise- but thankfully that can be dialed back. For some looks it's just what the doctor ordered. The minute I need it for a real shipping video I'll probably buy it.
 
I've tried many times and many emails to film convert about a F35 profile, and they say they will get to it eventually but I wouldn't hold my breath.

if you want to use a suitable profile (in PP)
just stick the lumetri plugin first, choose Macs slog to cineon LUT (makes it cineon log)
then film convert second and then choose arri Alexa log as profile. (Alexa is in cineon log)
Bam!
 
In Resolve, same thing:
input 3D LUT macs slog to cineon
on node select ofx filmvonvert
choose arri Alexa log c
Bam!
 
Has anyone tested out the DCDM REF PJ color space setting (as opposed to s-gamut)? Apparently it's compliant with the DCI standard.
 
If anyones interested, I'd like to share my experiences with grading F35 Slog footage, namely film print emulation. I'm no expert, but I want to share what I've learnt and maybe it can help others and others can help me with what they've learnt.
I'll try keep it as brief, yet as informing as possible.
I am technical enough to understand what I'm doing, but in no way an expert with all the technical jargon to explain fully, but I'll do my best to summarize.

Film print emulation is what most of us want, and why not? thats what movies and good music videos have.
For ages movies were shot on film, processed, edited, then to be shown in theatres, they had to be put back on positive film stock (kodak, fujifilm), which had "characteristics" that we've all grown to love, and see as the "movie look"

Film emulation print LUTs are "look up tables" that are developed to mimic various film stock characteristics (kodak, fujifilm), that are applied to footage through various applications that support LUTs (Resolve, speedgrade, etc etc)
This is done to preview what the film would look like once printed to film stock, but you can certainly use the LUT to "bake" in the print stock look.
Movies are done this way often, weather shot digital or on actual film.

Understand that applying a film LUT is not as simple as whacking it on. The film print LUTs are expecting film neg density, a gamma if you like, which was named "Cineon" back in the day. So the film LUTs are expecting "Cineon" gamma curve, not Slog/Panalog, Clog etc.

To get "Cineon" gamma curve from Slog, one has to engineer an appropriate conversion that is mathematically correct (it is described in the sony slog white papers)
Mac did this for us (and its actually also LUT itself!)
This Slog to Cineon conversion must happen first, then slog will be converted in "cineon" space, ready for Film print LUTs.

Film print LUTs not only curve your tonal range into film like curves, but also shift your colour range into film like ranges, which would be very hard and time consuming to do manually without the LUTs.

Firstly, if you keen on this, get yourself these LUTs:

1) "s-log to cineon" made by macgregor. https://dl.dropboxusercontent.com/u/... to cineon.zip free!
2) "Osiris LUTs" http://vision-color.com/osiris/ sorry but not free.
3) Kodak and Fujifilm LUTs: http://juanmelara.com.au/downloads/log2hd_cube_luts.zip

In Resolve, put LUTs in: /Library/Application Support/Blackmagic Design/DaVinci Resolve/LUT

Modes of quick good film looks:

1) LUTs
2) Film convert plugin (for most NLE's and grading software)

Filmconvert also uses built in LUTs to choose from, but the difference between LUTs and Filmconvert, is that Filmconvert is a one stop convenient solution that is a plugin for most NLE'sand grading packages, and it has more options like adding film grain etc.
But Filmconvert needs a camera profile for any given camera, that is to convert the gamma response of each camera sensor to cineon space (much like the slog to cineon LUT i was on about) and if your camera hasn't been profiled by Filmconvert you pretty much stuffed (like no F35 profile)

But a work around if u wanna use filmconvert, is to apply Macs Slog to Cineon LUT first in order of plugins, then apply filmconvert. In film convert camera profiles choose "Arri Alexa LogC" (which is in fact cineon space) Then choose your desired film print lut.

To get LUTs applied in various NLE's before the film convert plugin, use a plugin that can load luts. e.g:

In Premeire Pro apply the "Lumetri" plugin (which loads LUTs) select Macs Slog to Cineon
In FCP i think "LUT buddy" will do.
Then apply filmconvert with "Alexa" as camera profile, then choose film print of choose within filmconvert.

Now the other method of film looks is with just film print LUTs.
Example here is with Resolve, but same idea will work with other grading packages:

In project settings go to look up tables, choose the following:

3D input: Slog to Cineon
3D output: desired film print LUT
Then in the "Colour" window, balance your exposure with offset slider, and move the "offset" color wheel to balance Colour.

or for another look:

3D input: slog to cineon
3D output: Arri Alexa to rec709
Then add your film luts on the last node of your work (best on last node or else clipping can occur very easily)

Resolve has quite a few built in film stock LUTs from kodak and fujifilm to choose from.

If you don't use/have resolve, there are film stock LUTs here: http://juanmelara.com.au/downloads/log2hd_cube_luts.zip

Using LUTs doesn't magically "grade" your footage. You still have to balance your shots and tweak them. The LUTs sit at the input and output, and you grade in between.

Hope this makes any sense.

Example done in Resolve
3D input: Slog to Cineon
node 1: Balanced exposure, colour balance
final node: M31 Log LUT
3D output Ari alexa to rec709 LUT:
Untitled_1_87_1.jpg
[/URL] image[/IMG]



 
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I couldn't be more grateful for a community of people who compress hundreds of their own hours into pages in these forums. Thanks for the walk-through Jusgorilla and to everyone sharing their methods, one of my biggest learning curves with the f35 has been understanding the F35 log and how to properly handle it.
 
Been playing with what Jusgorilla has shown us all, and it works pretty well. What LUT you choose between the Input Cineon and Output Arri LUT will be key....

Does anyone have experience with the F35 footage going very warm when you add some LUTs? As there is no clear white balance adjustment in Resolve, i find it hard to back off some of the colors sometimes. I have for sure become a lazy grader after working with Red files for the last 2yrs, as it was a 2second process to balance your color if needs be.
 
TheWakePlace.com said:
Been playing with what Jusgorilla has shown us all, and it works pretty well. What LUT you choose between the Input Cineon and Output Arri LUT will be key....

Does anyone have experience with the F35 footage going very warm when you add some LUTs? As there is no clear white balance adjustment in Resolve, i find it hard to back off some of the colors sometimes. I have for sure become a lazy grader after working with Red files for the last 2yrs, as it was a 2second process to balance your color if needs be.
Click to expand...

The colour window section must be set to "Log", not "Primaries", then play with "offset" wheel and you can balance the colours easily (usually a pull towards blue gets it right)
Screen Shot 2014-02-21 at 8.41.06 PM.jpg

Hope this helps
 
ummm yea... i've graded 21 features in the last 24 months, so i prolly qualify as a pro colorist... four of those films were shot on Slog, one on F3's, three on F55's

loads of experience with film DI, so i well know what Cineon is and what film stock emulation luts are

i do have some quibles with the details presented, but the theory's advanced make sense to me

1) any LUT or transform that is looking for a cineon LOG input needs an adjutment layer/node before it.. a decade ago i had a scanner op adjusting the film scans shot by shot before they entered the gradeing suite... the current equlivent is to adjut the RAW data to meet the expected input values for the next transform -or- to adjust the media before the LOG-> LIN transform

2) any "filmstock emulation" or "filmprint emulation" is usualy a pretty bad joke.. the only exception is a LUT supplied by a lab that is callibrated to their current lab spec's, and let me say one more time "current" as is i have done DI's where the lab has updated the viewer LUT three times as their chemistry changed..

3) Film print has a very diffrent target from 709 in terms of both color and density, you really need to know what the LUT is transforming to, and what it's expecting to transform from... say from Cineon to be displayed on a monitor set to D65/25Fl... now you can't get above around 80% peak whites as the LUT is throtling your screen down to the deniesty values of a film print, and shifts it all to yellowish as the white point shifts to about D54

4) you cannot see a filmprint emulation accuratly on anything short of an OLED, Dolby or callibrated projector set to P3 anyway

5) the workflow i have used on the Slog shows is
For video delivery;
- set monitor to 709 / broadcast legal
- adjustment layer (or node in some systems) for density and white ballance
- Slog -> 709 LUT ( from Sony, not some of the rather destructive and to my eyes ugly home brews)
- what ever else it takes to look great and match across the scenes

For film out / DCP
- set monitor to P3 / full range
- grade in LOG until it looks great and matchs across the scenes
- re-set mon to 709, add a P3 to 709 LUT to the timeline and do a trim pass

F6) filmprints are warmer/desaturated in the highlights and colder in the shadows, so most "film emulation" LUT's do much the same as you doing the same thing in your grade, i have maybe 100+ "look" LUT's in my libary and never use any of them, i can just get there faster without the constraints
 
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Grug said:
Give the Filmconvert BMC log profile a go, with a few very slight tweaks I got some delightful results on SLOG from the F3.
Click to expand...

Great to know.

Question for the users of Filmconvert... Are any of you using the plugin in Resolve and how well is it working and how well is it working on both Windows and Mac? The plugin format is relatively new and I suspect there may be issues.
 
Andrew Stone said:
Question for the users of Filmconvert... Are any of you using the plugin in Resolve and how well is it working and how well is it working on both Windows and Mac? The plugin format is relatively new and I suspect there may be issues.
Click to expand...

I've messed with the FilmConvert plug in Resolve. I'm on a PC. It works OK. I just don't much like what it does. It feels very heavy handed to me by default. Like everything is turned up to 11 on the dial. Of course it has sliders to pull that stuff back, but then that's 4 more values I gotta twiddle. But once you've got it dialed in it looks OK if you're after a certain look. It seems stable enough. Hasn't crashed me out or anything.
 
Dermot, thanks a lot for the info! Do you happen to have that slog->709 LUT from Sony? Would you care to dropbox it?
 
Andrew Stone said:
Great to know.

Question for the users of Filmconvert... Are any of you using the plugin in Resolve and how well is it working and how well is it working on both Windows and Mac? The plugin format is relatively new and I suspect there may be issues.
Click to expand...

I'm using the Resolve-based OFX plugin, running Mavericks on Mac; it's been flawless so far, zero issues. In fact I'm finding Resolve 10.1 a substantially more stable build on the whole than any previous versions of it I've used (I had substantial issues with the original v10.0)
 
I am finding the same thing on Windows as far as the performance of Resolve 10.1. I have, however, been a bit gun shy about the OFX stuff after hearing a lot of moaning about it over the past couple of months.
 
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