GH5 to Alexa Conversion

[hypp]

@Sage What's your background? You obviously seem to know a lot about color and the science behind it. How did you learn all of this? 

[Sage]

13 minutes ago, hypp said:

@Sage What's your background? You obviously seem to know a lot about color and the science behind it. How did you learn all of this? 

I went to film school, and have since been making commercials for a fixed index annuity company that air on a lot of Tv channels

Where I really, really learned though - I am an obsessive, slightly autistic person, who is obsessed with making movies, and exactly replicating the aesthetic of those movies that astound me

Programming is entirely self taught. I began in grade school, making games on the calculator (Ti-83) for the other kids to play. I called the effort 'Sage Games', after an rpg game I drew on paper called... "Sage-Ru 26"

My goal is to make a movie that really speaks to me personally, and the idea of doing that thrills me. Its the one constant

[mirekti]

What would be a good source of LUTs for LogC in case I wanted to play around?

 

[thebrothersthre3]

Film school seems pretty overrated. Lots of good info and of course in the end you just have to put in the work. 

and then there is me who is color blind ?

[Sage]

11 hours ago, mirekti said:

What would be a good source of LUTs for LogC in case I wanted to play around?

There are the official Arri issued photometric display luts, that are the minimum starting point for a grade to interpret LogC correctly (and used for dailies):

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

There is VCImpulz, which has good LogC support, Linny, and those behind closed doors at Technicolor etc.

10 hours ago, thebrothersthre3 said:

Film school seems pretty overrated. Lots of good info and of course in the end you just have to put in the work. 

and then there is me who is color blind ?

Yes, I think so. Better to go and make a film (or three) right out of the gate, with whatever resources you've got.

My coworker is color blind, and I'm always talking to him about what I'm working on with Emotive Color hehe

[Flyingsheep]

What are your recommended profile settings when shooting in HLG for the HLG to V-Log L transformation? Heavily considering picking up ghA soon, thanks

[Sage]

21 hours ago, Flyingsheep said:

What are your recommended profile settings when shooting in HLG for the HLG to V-Log L transformation? Heavily considering picking up ghA soon, thanks

That one is easy to set - its a more locked off profile like VLog. I would just recommend Sharpness and NR to be set to -5 for optimal texture. Be sure to check out the PDF (which is attached, as its now only 1.5MB)

GHa Documentation V3.pdf

Another from Ryan, great shots throughout (v2 Soft):

ASHLAND

[hypp]

On 10/27/2018 at 12:12 AM, Sage said:

I went to film school, and have since been making commercials for a fixed index annuity company that air on a lot of Tv channels

Where I really, really learned though - I am an obsessive, slightly autistic person, who is obsessed with making movies, and exactly replicating the aesthetic of those movies that astound me

Programming is entirely self taught. I began in grade school, making games on the calculator (Ti-83) for the other kids to play. I called the effort 'Sage Games', after an rpg game I drew on paper called... "Sage-Ru 26"

My goal is to make a movie that really speaks to me personally, and the idea of doing that thrills me. Its the one constant

That's great, I'd like to learn more about color correction. Do you know of any good free resources for a semi-beginner (I do know how to do basic corrections in Resolve) wanting to become a better, more advanced colorist, preferably in Resolve? 

[Flyingsheep]

1 hour ago, Sage said:

That one is easy to set - its a more locked off profile like VLog. I would just recommend Sharpness and NR to be set to -5 for optimal texture. Be sure to check out the PDF (which is attached, as its now only 1.5MB)

GHa Documentation V3.pdf

Cool, and saturation at -5 as well?

[FreshGiant]

Sage, I bought the LUT and I have been blown away. I want to thank you so much. It really unlocks the GH5. I think it would be great if you can do more video tutorials as well on the best uses. 

Also, without having to do all the work of making a new GH5s lut, could you just do a lut that matches the GH5 to the GH5s V-LOG (GH5 looks a bit more green to me) the way you do a C-LOG conversion?

[Sage]

1 hour ago, FreshGiant said:

Sage, I bought the LUT and I have been blown away. I want to thank you so much. It really unlocks the GH5. I think it would be great if you can do more video tutorials as well on the best uses. 

Also, without having to do all the work of making a new GH5s lut, could you just do a lut that matches the GH5 to the GH5s V-LOG (GH5 looks a bit more green to me) the way you do a C-LOG conversion?

 

Thank you! I'd certainly like to do that, now that V3 is out

That's a way to do it, ironically its just as tricky (cam to cam, vs profile to profile)

@hypp Others could probably better speak to the resources out there. I highly recommend shooting films and diving in headfirst, its a great bootcamp (the method to my madness)

I'd especially like to emphasize luminance placement, which has perhaps the single biggest effect on image perception. Conform to cinema standard luminance, and things really start to click. Read through the second half of page 2 of the Pdf, and study these waveforms

GHa Documentation V3.pdf

Supplemental Waveforms (PDF).zip

[hypp]

@Sage I just read the documentation and looked at the waveforms but there are some things that really confuses me due to my lack of knowledge. What's the difference between exposure (set by lift, gamma, gain) and luminance? I learned to set exposure by the color wheels (lift, gamma, and gain) and I can't seem to understand what to do with the luminance when you have a shot without a person. Do you only set the black and highlight value and disregard the skin tone value or do you replace it with something else? My reason for this confusion is because in my head I translate the black level (set by lift), skin tone or mid tones (set by gamma) and highlight (set by gain) which is most likely wrong. 

 

Quote

When using the luma curve, it should retain a single, smooth, contiguous arc over the majority of its run, such that elements in the scene conform to these ranges without contortion.

 Could you give an example of how that could look like and how it's not supposed to look like? 

[Maverick530]

I just got around to downloading the files today from the email, but I think I'm missing some stuff, I don't see LogC, Main, Linear or any of that stuff. 

 

Edit: Nevermind, I found it in another download

[Sage]

16 hours ago, hypp said:

@Sage I just read the documentation and looked at the waveforms but there are some things that really confuses me due to my lack of knowledge. What's the difference between exposure (set by lift, gamma, gain) and luminance? I learned to set exposure by the color wheels (lift, gamma, and gain) and I can't seem to understand what to do with the luminance when you have a shot without a person. Do you only set the black and highlight value and disregard the skin tone value or do you replace it with something else? My reason for this confusion is because in my head I translate the black level (set by lift), skin tone or mid tones (set by gamma) and highlight (set by gain) which is most likely wrong.

 Could you give an example of how that could look like and how it's not supposed to look like? 

Exposure, as used in the Pdf, refers to the luminance shift which occurs in camera (f-stop, shutter). This is a fixed shift that affects the entire image, most similar to the Offset control in post. Luminance is used to refer to the brightness of things in post, which can be altered by any controls as you see fit.

With cinema standard luminance, the aim is the big picture. Exact IRE targets give boundaries and get things started. The principle underlying those targets is that certain scene types and lighting environments hit a consistent brightness throughout a film. Hence, a tree, ocean or sky will place in context with whether it is night, dusk or midday sun etc. The different environments shown in the waveforms will help give a sense for how to place a scene type in your film (Summarized as: Consistency within ranges)

No need to stress over placing each individual scene element though - they are all optically tied together, through the scene gamma. That's what I'm referring to in the note on the luma curve. It should be a smooth arc, as shown on the second DaVinci page (away from home for a couple days). Once black is set with that bottom point, its simply a matter of placing the middle and top points (with the Resolve curve, which moves ideally). A problematic curve would involve extra points, that create dips and rises in that gamma (wrangling the data, so to speak)

22 hours ago, Flyingsheep said:

Cool, and saturation at -5 as well?

Saturation at default* (wider gamut)

[deathly_twig]

Some shots taken this evening. Not much grading other than V3 and some minor tweaks. These were wrapped in prores, as I used the Ninja V, so they aren't optimal. But I am really loving V3! So beautiful.

[Sage]

5 hours ago, deathly_twig said:

Some shots taken this evening. Not much grading other than V3 and some minor tweaks. These were wrapped in prores, as I used the Ninja V, so they aren't optimal. But I am really loving V3! So beautiful.

Those look fantastic. And as long as you're in anything but Premiere, ProRes is perfectly fine.

Can you send me a raw DPX of that last still?

[Lambo]

12 minutes ago, Sage said:

Those look fantastic. And as long as you're in anything but Premiere, ProRes is perfectly fine.

Can you send me a raw DPX of that last still?

What is the issue with Prores and Premiere?

[Sage]

2 hours ago, Lambo said:

What is the issue with Prores and Premiere?

Premiere distorts the color space of ProRes - most noticeably saturated red. It also hides the correct levels flagging of VLog (this is correctable with the PRE).

I will do a PRE to fix Premiere ProRes exactly, eventually

[deathly_twig]

2 hours ago, Sage said:

Premiere distorts the color space of ProRes - most noticeably saturated red. It also hides the correct levels flagging of VLog (this is correctable with the PRE).

I will do a PRE to fix Premiere ProRes exactly, eventually

I did use Premiere, unfortunately. So it's not the best it could be due to that! Will send over the DPX asap!

[deathly_twig]

So I just got my Mavic 2 Pro today, and decided to try the GHA conversion on it, in 10 bit mode of course, to see what would happen. I used the Cine-D pre, and then Linear. I still have to dial in my Mavic settings a bit more, but the lut seemed to work! Obviously not perfectly, but not bad. Now to get some better footage and more practice with this drone!