GH5 to Alexa Conversion

[DanielVranic]

10 hours ago, John Roque said:

@Sage eagerly waiting for the XT3 version! I converted the flog to vlog first then added GHA. Is this the correct process? What do you guys think!?

HMMMM. looks very good. Wondering if I should just do that.

[thebrothersthre3]

The question is it better than just doing Flog to Arrilog 

[DanielVranic]

17 minutes ago, thebrothersthre3 said:

The question is it better than just doing Flog to Arrilog 

Thats what I do right now. I think i explained it in a different thread - but i usually convert from FLog to 709 using curves and a CST, and then go from 709 to LogC and back to 709. That gives me my highlight roll-off and looks pretty.

But if this LUT can do both? and give me nice new colors? sign me up. 

[Sage]

I want to make true XT3 support a reality this year. I would recommend hanging in there

Even now, I am still working on the 5

[mercer]

Just curious... why work on cameras that are known to already have good color?

For instance, Blackmagic Film and LogC have similar properties with the biggest difference being in the midtone portion of the curve but both react “similarly” to each other’s LUTS.

Fuji already has good color, so why bother with an Alex version?

Panasonic makes sense... especially their 8 bit versions. Sony seems like another obvious option for your LUT process.

[Sage]

Sure; it depends on what you'd like. Fuji and BMD have very good, usable color. I personally will use P4K with GH5; I hope to have EC to do a production this summer.

8 bit is tricky; I'd prefer to only support 10 bit cameras, though I will try to find a way that will give viable production level results with 8-bit. I think Log is not really in the cards there.

 

Bit of really cool news; last weekend, the director of a film starring Josh Hartnett wrote to me to say that they were using the GH5 with EC as a pick-up cam alongside Alexa Minis and XTs.

He said that a senior Star Wars colorist was doing the grade, and said that 'everybody was very impressed' with it. I was pretty thrilled with that

[John Roque]

5 hours ago, DanielVranic said:

Thats what I do right now. I think i explained it in a different thread - but i usually convert from FLog to 709 using curves and a CST, and then go from 709 to LogC and back to 709. That gives me my highlight roll-off and looks pretty.

But if this LUT can do both? and give me nice new colors? sign me up. 

I have tried converting to Ari log from flog also and I don’t which I like better. There are differences but I’m just trying to see how close to the original process I can get until the official Xt3 version comes out. At the end of the day, I guess it’s whatever looks good to your preferences. Thanks guys. 

[androidlad]

X-H1 F-Log -> F-log/F-Gamut to V-log/V-Gamut LUT from LUTCalc -> GHa Daylight:

[thebrothersthre3]

39 minutes ago, Sage said:

Sure; it depends on what you'd like. Fuji and BMD have very good, usable color. I personally will use P4K with GH5; I hope to have EC to do a production this summer.

8 bit is tricky; I'd prefer to only support 10 bit cameras, though I will try to find a way that will give viable production level results with 8-bit. I think Log is not really in the cards there.

 

Bit of really cool news; last weekend, the director of a film starring Josh Hartnett wrote to me to say that they were using the GH5 with EC as a pick-up cam alongside Alexa Minis and XTs.

He said that a senior Star Wars colorist was doing the grade, and said that 'everybody was very impressed' with it. I was pretty thrilled with that

dang dude nice work! If you do one for the XT3 I'll definitely consider it. If it matches well with the GH5 it would be a great way to use both cameras without worrying about color matching. 

[RCV]

21 hours ago, John Roque said:

@Sage eagerly waiting for the XT3 version! I converted the flog to vlog first then added GHA. Is this the correct process? What do you guys think!?

looks pretty good

5 hours ago, androidlad said:

X-H1 F-Log -> F-log/F-Gamut to V-log/V-Gamut LUT from LUTCalc -> GHa Daylight:

great skintone

5 hours ago, Sage said:

Sure; it depends on what you'd like. Fuji and BMD have very good, usable color. I personally will use P4K with GH5; I hope to have EC to do a production this summer.

8 bit is tricky; I'd prefer to only support 10 bit cameras, though I will try to find a way that will give viable production level results with 8-bit. I think Log is not really in the cards there.

 

Bit of really cool news; last weekend, the director of a film starring Josh Hartnett wrote to me to say that they were using the GH5 with EC as a pick-up cam alongside Alexa Minis and XTs.

He said that a senior Star Wars colorist was doing the grade, and said that 'everybody was very impressed' with it. I was pretty thrilled with that

Sage you made it!!

[DanielVranic]

On 3/29/2019 at 6:12 PM, John Roque said:

I have tried converting to Ari log from flog also and I don’t which I like better. There are differences but I’m just trying to see how close to the original process I can get until the official Xt3 version comes out. At the end of the day, I guess it’s whatever looks good to your preferences. Thanks guys. 

I actually did the F-Log -> F-log/F-Gamut to V-log/V-Gamut LUT from LUTCalc -> GHa Daylight on my XT3 footage and it is beautiful!!!

[hypp]

@Sage Someone released an Arri Alexa lut for Sony slog2/3 cameras a while ago. You're obviously very experienced so would you mind sharing if you think it looks relatively close to the real Arri Alexa even though it's not an Alexa conversion?

 

[Sage]

There were some things that looked more right to me, like the boxing scene. I think that's a nod in the right direction to a LogC+709. Yellows, greens, and clipping for example didn't quite do it for me, but I am on a terrible blue tft laptop screen, which is all I have access to at the moment

[DanielVranic]

On 4/1/2019 at 9:45 PM, Sage said:

There were some things that looked more right to me, like the boxing scene. I think that's a nod in the right direction to a LogC+709. Yellows, greens, and clipping for example didn't quite do it for me, but I am on a terrible blue tft laptop screen, which is all I have access to at the moment

Hey Sage, I have a question. To make the best use of the LUT, do you prefer footage be overexposed and brought down? 

[Sage]

6 hours ago, DanielVranic said:

Hey Sage, I have a question. To make the best use of the LUT, do you prefer footage be overexposed and brought down? 

Overexposed slightly, so to speak (skintone at ~50-55 IRE for VLog). The goal is moderate exposure, rather than setting it just below clipping (or too low). When cinema luminance is placed in post, you should generally find that the image needs to get darker. Be sure to download and review the supplemental waveforms, page 3 of the Pdf, and the waveform guide; this is most helpful in getting a feel for where everything should place at the end.

[DanielVranic]

4 minutes ago, Sage said:

Overexposed slightly, so to speak (skintone at ~50-55 IRE for VLog). The goal is moderate exposure, rather than setting it just below clipping (or too low). When cinema luminance is placed in post, you should generally find that the image needs to get darker. Be sure to download and review the supplemental waveforms, page 3 of the Pdf, and the waveform guide; this is most helpful in getting a feel for where everything should place at the end.

ah shit, well I should probably have read those! 

So far I love it, i built the FLog-VLog LUT in LUTCalc and for about 80% of shots it works perfectly. But in shots where there is a huge gap from high to low its blows out the highs and crushes the lows. Whereas if I did a manual grade with curves it would be still OK. I totally understand it was never made for the XT3, but just trying to find a way to avoid that for now.

[hypp]

@Sage What's the difference between using this lut and using color space transform in Davinci Resolve V-Log to LogC and then rec. 709? 

[Sage]

They're very similar. That's the concept behind GHa; convert VLog to LogC, and follow that with Arri's 709 primaries. Cst uses the manufacturer's published specs for the gamut and gamma allotment of color spaces, and then does a transform between them. GHa is measured through the lens, and uses the EC component to apply the 709 primaries (for the EC variations)

On 4/3/2019 at 3:39 PM, DanielVranic said:

ah shit, well I should probably have read those! 

So far I love it, i built the FLog-VLog LUT in LUTCalc and for about 80% of shots it works perfectly. But in shots where there is a huge gap from high to low its blows out the highs and crushes the lows. Whereas if I did a manual grade with curves it would be still OK. I totally understand it was never made for the XT3, but just trying to find a way to avoid that for now.

Apply a hue-locked curve ahead of the conversion, to adjust the black and white points (with the conversion already applied). This will allow access to the entirety of the range

[DanielVranic]

15 hours ago, Sage said:

They're very similar. That's the concept behind GHa; convert VLog to LogC, and follow that with Arri's 709 primaries. Cst uses the manufacturer's published specs for the gamut and gamma allotment of color spaces, and then does a transform between them. GHa is measured through the lens, and uses the EC component to apply the 709 primaries (for the EC variations)

Apply a hue-locked curve ahead of the conversion, to adjust the black and white points (with the conversion already applied). This will allow access to the entirety of the range

Thanks for the tip. I have found that I am enjoying a 5-node workflow for this.

1. WB Corrections/Balances
2. Flog/FGammut-VLog/VGammut
3. Adjustment node, using the LGG wheels, (i do not know how to due a hue-locked curve, will look into it)
4. GHa/GHa Linear (depending on which look i am feeling)
5. Saturation/Balance adjust

That workflow has worked excellent for me so far! I need to look into those hue-locked curves though!

[Sage]

7 hours ago, DanielVranic said:

Thanks for the tip. I have found that I am enjoying a 5-node workflow for this.

1. WB Corrections/Balances
2. Flog/FGammut-VLog/VGammut
3. Adjustment node, using the LGG wheels, (i do not know how to due a hue-locked curve, will look into it)
4. GHa/GHa Linear (depending on which look i am feeling)
5. Saturation/Balance adjust

That workflow has worked excellent for me so far! I need to look into those hue-locked curves though!

That checks out; the hue locked curve is detailed in the Resolve section ('hue' layer mixer), and the 'Advanced' section of Premiere