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GH5 to Alexa Conversion


Sage
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11 hours ago, Sage said:

Apologies, I was away for a bit. An update - first, my dad is out of the hospital and recovering from surgery.  We are ostensibly through the worst of it.

Second, I ended up rewriting the complete engine. All legacy code has been replaced, in order to make extreme saturation projection more accurate, as well as make some improvements along the way (for example, the engine now features a 1D function at core)

Third, I've completed the S1/S1H/S5 conversion, as of yesterday.

It is the most recent LogC (SUP 11.1.1)

Fortunately the S series seems to have a better internal codec. The GH5 was uniquely problematic with its red/green macroblock splitting. To test gradient motion, film a white wall in darkness. Then, move a spotlight back and forth to see If there is banding revealed as the spotlight falls into darkness. Better codecs will handle this smoothly, while more compressed codecs may have some visible bands moving in the gradient. This is the kind of thing that can crop up in lens flares, or panning across gradients.

Thank you very much for the explanation! Happy that your dad is recovering! But I have noticed that in underexposed situation and in warmer lights the yellow hue with p4kalex shifts to green. Thus I wasn't able to use the lut in those kinds of situations. Is it simply caused the the p4k colorscience or is this common with all v4 color? Since when using the v3 ghalex all the brown and yellow hues have very nice colors to them. Thank you very much! 

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1 hour ago, Sage said:

@jack jin Is it the Daylight conversion? This is common when Daylight is applied to tungsten lighting

@TomTheDP Sure, that's possible; I am at a crossroads, wherein there are some experimental ideas I've wanted to mess around with for years. Now with the engine complete, I feel more free to explore them

Ohhhhhh, so that's why? If I use tungsten version of the lut does the yellow hues and brown hues stays consistent in warmer lights and underexposed situations? Thank you for answering my questions!

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On 10/16/2020 at 2:47 PM, Sage said:

@jack jin That's the ticket; one might also opt to use day balanced bulbs or CTB gels indoors

Will the S1 power grades work for EVA1 and Varicam?

Also is it possible to make these transforms into LUTs? Can't you export a power grade as .cube?

Would it be possible to do a more accurate "film look" this way? I don't understand why FilmConvert doesn't really look that good to me, but the Brim does a pretty good job to my eyes and Arri originally had a special Log C setting meant to emulate film scans. It was problematic and they discontinued it, but the colors were a perfect math to 5219 I think. Log C now has its own look, a bit more like reversal than color negative imo.

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4 hours ago, HockeyFan12 said:

Will the S1 power grades work for EVA1 and Varicam?

Also is it possible to make these transforms into LUTs? Can't you export a power grade as .cube?

Would it be possible to do a more accurate "film look" this way? I don't understand why FilmConvert doesn't really look that good to me, but the Brim does a pretty good job to my eyes and Arri originally had a special Log C setting meant to emulate film scans. It was problematic and they discontinued it, but the colors were a perfect math to 5219 I think. Log C now has its own look, a bit more like reversal than color negative imo.

Have you tried filmconvert nitrate? The cineon log conversion has spot on colors and contrast, it's their normal emulation laced with their heavy print film colors that looks crap. 

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50 minutes ago, jack jin said:

Have you tried filmconvert nitrate? The cineon log conversion has spot on colors and contrast, it's their normal emulation laced with their heavy print film colors that looks crap. 

Interesting... where do you from the cineon conversion? Is there a good cineon to rec709 LUT? The normal emulation looks like magic bullet to me, yeah.

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@HockeyFan12 Indeed, it likely would work fairly well with the Eva and Varicam, though it wasn't made for their sensors. Hence, it won't quite match its accuracy with the S1.

One could export them, though interpolated cubes would be preferable (interpolation is most accurate).

One may use LogC intended film conversions, indeed. LogC is often better supported (they've kept a consistent image for more or less 10 years, remarkable among cameras)

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1 hour ago, HockeyFan12 said:

*where do you go from the cineon conversion

Three nodes, third node you input the status m density rgb matrix shown here:

into davinci resolve, set the saturation to 60. On the second node you first put in filmconvert nitrate, select camera profile (must be log for cineon to show up), and then put print film emulation to 0, then you go into the white balance tab to adjust the white balance until it looks neutral, these matrix mess with the white balance so the image might look very magenta and warm, this is where you fix it. I like to use the classic rgb matrix, it gives me the best skintones. Going back to the third node, I just simply manually adjust the gamma/curve to my liking, by setting the black level and then applying a slight s curve to the footage, or I use CST to conform the gamma from cineon log to rec709 with luminance mapping turned on.

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30 minutes ago, jack jin said:

Three nodes, third node you input the status m density rgb matrix shown here:

into davinci resolve, set the saturation to 60. On the second node you first put in filmconvert nitrate, select camera profile (must be log for cineon to show up), and then put print film emulation to 0, then you go into the white balance tab to adjust the white balance until it looks neutral, these matrix mess with the white balance so the image might look very magenta and warm, this is where you fix it. I like to use the classic rgb matrix, it gives me the best skintones. Going back to the third node, I just simply manually adjust the gamma/curve to my liking, by setting the black level and then applying a slight s curve to the footage, or I use CST to conform the gamma from cineon log to rec709 with luminance mapping turned on.

Interesting. That particular workflow is a bit over my head, but the cineon conversion reminds me of the cinny LUT here:

https://www.thebrim.pictures/sucomo.html

Seems really useful.

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34 minutes ago, HockeyFan12 said:

Interesting. That particular workflow is a bit over my head, but the cineon conversion reminds me of the cinny LUT here:

https://www.thebrim.pictures/sucomo.html

Seems really useful.

The linny lut is not strictly accurate, because you don't know what display prep they based the original emulation on.  It's a emulation of a scan of a print of a negative. There is so many variables that could change the colors drastically within their pipeline. What if the color timing was off during the printing process? Did they print the negative optically or through laser? Did the negative or print went through Digital Intermediate before the print or scan? What was the machine that scanned the print? Where as the filmconvert nitrate is just simply a conversion to the filmstock's cineon colors. Not to mention the linny lut is ridiclously expensive, with only one stock, where as filmconvert nitrate got 19 stocks, with options for grain emulation for 1/5th the price. And the cinny lut only includes one stock, which filmconvert has, while costing 395 bucks for one lut. It's absolute insanity how much they think they can charge for their luts.

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8 minutes ago, jack jin said:

The linny lut is not strictly accurate, because you don't know what display prep they based the original emulation on.  It's a emulation of a scan of a print of a negative. There is so many variables that could change the colors drastically within their pipeline. What if the color timing was off during the printing process? Did they print the negative optically or through laser? Did the negative or print went through Digital Intermediate before the print or scan? What was the machine that scanned the print? Where as the filmconvert nitrate is just simply a conversion to the filmstock's cineon colors. Not to mention the linny lut is ridiclously expensive, with only one stock, where as filmconvert nitrate got 19 stocks, with options for grain emulation for 1/5th the price. And the cinny lut only includes one stock, which filmconvert has, while costing 395 bucks for one lut. It's absolute insanity how much they think they can charge for their luts.

Yeah, it's not cheap. Arri also had a similar mode on the Alexa that they discontinued, it was used when the Alexa was to be intercut with film.

Anyway, thanks for the info on the cineon mode. Very cool.

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4 hours ago, HockeyFan12 said:

Interesting. That particular workflow is a bit over my head, but the cineon conversion reminds me of the cinny LUT here:

Please don’t post that kind of horrible scam here. Juan Melara already proved it, but unfortunately he has taken the video down. He used to give away a better version of the “Linny LUT” for free.

https://*banned URL*/2018/01/lut-smash-showdown-colorist-reverse-engineers-607-linny-lut-free

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On 10/19/2020 at 2:34 PM, Simon Young said:

Please don’t post that kind of horrible scam here. Juan Melara already proved it, but unfortunately he has taken the video down. He used to give away a better version of the “Linny LUT” for free.

https://*banned URL*/2018/01/lut-smash-showdown-colorist-reverse-engineers-607-linny-lut-free

That link is banned, and also not useful because it links to the original source, which has since been taken down.

Luckily, the internet never forgets:

https://web.archive.org/web/20180407123236if_/http://juanmelara.com.au/blog/re-creating-the-600-brim-linny-lut-in-resolve
https://static1.squarespace.com/static/580ef820e4fcb54017eba692/t/5a560498ec212d5f4a972d25/1515589920801/The_Brim_Linny_Rebuild.zip
https://web.archive.org/web/20190227062207/http://juanmelara.com.au/s/The_Brim_Linny_Rebuild.zip

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On 10/18/2020 at 11:08 PM, HockeyFan12 said:

Arri also had a similar mode on the Alexa that they discontinued, it was used when the Alexa was to be intercut with film.

I found the Arri film matrix numbers, and used the Matrix drx printer code to inject them into DaVinci. I'm not sure what to make of it.. it is a lot more saturated for sure. Here are the numbers and the lut/powergrade:

1.271103    -0.284279   0.013176

-0.127165   1.436429   -0.309264

-0.129927  -0.510286  1.640214

Arri Film Matrix Download

On 10/19/2020 at 7:46 AM, Hicham said:

Glad to hear that your Dad is recovering !

And cool to hear that the S series conversion is finished. When do you plan to release this new S Series Lut Pack ?

It lives! The Sony a7s III conversion is now complete as well.

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1 hour ago, Sage said:

 

It lives! The Sony a7s III conversion is now complete as well.

Very excited about your S1 LUTs. I've been using the GH5 luts on my S1 so far and seems to work great.

Are the GH5 and S1 luts very different? Do you have any samples of the Lut on the S1 or S1H? I looked on the Emotive Color site and couldn't find any. Thanks for your work and for being a presence on here.

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16 hours ago, Sage said:

I found the Arri film matrix numbers, and used the Matrix drx printer code to inject them into DaVinci. I'm not sure what to make of it.. it is a lot more saturated for sure. Here are the numbers and the lut/powergrade:

1.271103    -0.284279   0.013176

-0.127165   1.436429   -0.309264

-0.129927  -0.510286  1.640214

Arri Film Matrix Download

 

It lives! The Sony a7s III conversion is now complete as well.

Thanks... weird...

Well it certainly is green. 

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