GH5 to Alexa Conversion

[Sage]

38 minutes ago, DaveAltizer said:

@Sage I'm loving all the work you're doing on all this. I really respect you for that. 

Thanks Dave, I really appreciate that! No less than perfect will do.

 

Side note in conjunction with the OLPF update (motion): All-I, 2K or 4K is optimal

[Wild Ranger]

Hi everybody. I just want to share a frame of a mini test i did.

I used the Daylight LUT and converted to Arri LOG-C. The Skintones are incredible!

Damn I'm looking good! 

[Sage]

1 hour ago, Wild Ranger said:

Hi everybody. I just want to share a frame of a mini test i did.

I used the Daylight LUT and converted to Arri LOG-C. The Skintones are incredible!

Damn I'm looking good! 

I like it! Did you use Arri's Rec 709?

[Wild Ranger]

1 hour ago, Sage said:

I like it! Did you use Arri's Rec 709?

I tried different methods, in this used Filmconvert for Arri Log-C

[Sage]

10 minutes ago, Wild Ranger said:

I tried different methods, in this used Filmconvert for Arri Log-C

Be sure to incorporate Arri's 709 RGB primaries; that's a critical step. This brings up skintone, especially relative to blue, all things equal. Main/Soft incorporate this, as well as a nicer starting point than standard Arri 709

Here is a breakdown on Arri 709:

http://bjorkvisuals.com/articles/demystifing-arri-alexas-rec709-lut

And you can dial in a post-production variation of the Rec 709 Lut to your taste here:

https://www.arri.com/camera/alexa/tools/lut_generator/

 

[JeremyDulac]

Here are a couple quick stills from some current work - shooting Vlog. First still is just with Gha with some grain, second with a film print lut and the gamma converted to Cineon. Loving this GHa lut!!

[Sage]

Its looking slick! Is there a little bit of olpf texture in there?

I always liked the way foliage and blue sits in with skintone with Alexa

[JeremyDulac]

27 minutes ago, Sage said:

Its looking slick! Is there a little bit of olpf texture in there?

I always liked the way foliage and blue sits in with skintone with Alexa

Hey thanks! Yep, i used your olpf suggestion, loving the effect. I agree, that blue green separation along the skyline is fantastic. 

[Sage]

1 hour ago, JeremyDulac said:

Hey thanks! Yep, i used your olpf suggestion, loving the effect. I agree, that blue green separation along the skyline is fantastic. 

Human + Skyline, one of my favorites with this color science

(120fps, 8-bit no less)

[JeremyDulac]

A Couple more. First with just GHa and second with my film look. Superb highlight roll off!!

Side note - My god does the contrast get messed up with direct photo uploads!! Color looks SO faded compared to the actual stills. I gotta get a flickr account lol.

 

 

[Sage]

I was wondering how that one would look with V2; its quite stunning as the sun hits the scene!

Did you try .png? Curious if the colorspace will be handled differently for uploads

I am a big fan of the natural color handling of plain GHa, but the contrast in the film look with the sun is great. And my god, skintones

 

Btw, I took a little step towards something big this week, I know you'll love it.

[JeremyDulac]

Png does seem to help a lot with these posts.

Your skintones are second to none with your lut. No one else is doing what you are with the subtractive nature of GHa. The smoothness and gradation of color is totally amazing!

Always look forward to your updates!

 

[Sage]

1 hour ago, JeremyDulac said:

Png does seem to help a lot with these posts.

Your skintones are second to none with your lut. No one else is doing what you are with the subtractive nature of GHa. The smoothness and gradation of color is totally amazing!

Always look forward to your updates!

I think that's my favorite still you've posted. Totally sick (in a good way)

And thank you very much! I might bring the Emotive Color component to Alexa users, as many crews likely don't get the best from LogC

[mercer]

So, sorry I don’t mean to be rude or anything but as good as all of these samples are... which they are, they look great! But I don’t really see Alexa color. I see really good Panasonic color with refined tonal gradations and highlight roll off, but I don’t get the Alexa reference or comparison.

Btw, @Wild Ranger I recently saw your short film Record on YouTube and I really have to say what a great piece of work that was. That short alone could keep people in the GH5s camp instead of buying a P4K. Great images, great story and excellent directorial choices!!!

It’s definitely one of the best low budget short films I’ve seen in a while. 

[Sage]

Thanks Mercer,

I think that's the greatest thing that keeps people from immediately buying up all the GH5(s) left on the shelves. If this is real, then why is it still possible to find a GH5? Why isn't the film industry going crazy en-masse? It simply seems incredulous that a precision conversion from GH5 VLog to Alexa LogC could even be possible (before I had the idea of how to go about it last year, this is exactly how I felt, despite pondering the idea for many, many years)

With V2, I endeavored to prove the value of the thing beyond a doubt, by supplying raw footage directly from the cameras. I intend to keep supplying more raw side-by-sides as I have the moments to shoot them. The need for this was especially driven home months ago by a conversation I had with you in another thread, when I only had V1 (based on a single measurement). This is one of the main factors that drove me to get the Arri, because I would be able to really perfect the conversion, and shoot endless side-by-sides.

The raw side-by-sides allow everyone to prove for themselves, that it is not merely Alexa-like, but indeed a precision match. There is a sense that the Alexa, by virtue of its sticker shock, has something unattainable going on. But it is, in fact, quantifiable (a continuous fluid colorspace, with predictable sensor response to a given light)

Alexa + GH5 Daylight

Alexa + GH5 Tungsten

Alexa + GH5 Tungsten Skintone

Alexa + GH5 Tungsten OLPF

I'm going to share these as LogC stills, which you don't need GHa to be able to see. (though the raw footage part is what I'm most proud of)

*There is an issue with far red cutoff under Tungsten. I intend to address that eventually, when I've got some time

[mercer]

And I appreciate the work you’ve put into it. And I don’t mean to sound like a grumpy dick on a forum... Grr.

I’m a self professed bad colorist. So obviously take my opinion with a grain of salt. But a lot of the images, although really nice seem to be missing some of the magic that an Alexa offers?

I wonder if it may be a good idea to take specific high end color grades from popular films and try to emulate those looks?

For instance, when I think Alexa, I think The Revenant, or I think of The Witch.

Btw, I remember that conversation and I appreciate the samples, but with life being as hectic as it is lately, I’ve been on my phone more than my computer, and I cannot download the images.

Anyway, nice work and carry on. I enjoy seeing what you guys are coming up with. 

[Sage]

Here are the goods - as they are Log, they are best looked at in Vectorscope/Waveform, or with matched boosted saturation & contrast to verify that they are the real deal

GH5 VLog

GHa LogC

Alexa LogC

GH5 VLog

GHa LogC

Alexa LogC

GH5 VLog

GHa LogC

Alexa LogC

GH5 VLog

GHa LogC (With OLPF Sim)

Alexa LogC

[Sage]

1 hour ago, mercer said:

I’m a self professed bad colorist. So obviously take my opinion with a grain of salt. But a lot of the images, although really nice seem to be missing some of the magic that an Alexa offers?

I wonder if it may be a good idea to take specific high end color grades from popular films and try to emulate those looks?

For instance, when I think Alexa, I think The Revenant, or I think of The Witch.

What I'm able to do is precisely match the LogC format, and add a rich neutral starting point (EC). Its true though, that there is a lot that goes into the magic of a cinematic image. I've seen some visually terrible Alexa films shared on forums; those were funny and eye-opening, because they reveal that the Alexa can only do so much for a production. I think its likely they effectively had no color backend, which the EC component addresses. Though all the factors come together to make a great image -

The great DP, who

- Uses great organic lenses

- Frames well (with motion)

- Lights beautifully

Costume and Set Designers (with a budget), who

- Coordinate the color palette in concert with the story atmosphere, and the colorist's intention

And a great Colorist, who

- Carefully balances (with restraint and good taste) all shots with each other

- In service of a singular atmospheric concept for the scene

I do think these are very attainable. And when a production is in motion, its really pretty cool what will result as they all come together.

[Sage]

Here's my emulation of the Witch frame;

I just tried to match the Vectorscope, the Waveform was mostly there (just a little gamma drop)

I dropped saturation to 16 (from the node default of 50), and on the second node mostly adjusted midtones toward greenish cyan. Then I eyeballed the white of the highlights, and a touch of warmth to the shadows

The Witch Vectorscope

Original Vectorscope:

New Vectorscope:

[mercer]

Great reply. I look forward to seeing how this progresses. The color is definitely better than stock Panny color, so right off the bat you’ve made the GH5 more attractive.