How to create SLog3 full data range “test chart”?

I need to create test file(s) that will:

1. Use SGamut3.cine color space and SLog3 gamma
2. Have 10 step gray scale and color bars
3. Use full (extended) data range from 0 to 1023 (from -7IRE to 109IRE) and is exported as such

How can I do that, please?

Maybe this DCTL can help you partially setting that up.
https://procolor.ist/exposure-dctl/

The color bars you could take from the generator in Resolve although I'm not sure which colors you desire to have in that space and to what purpose.

1 and 3 are at odds. In 10 bit notation the lowest value on the S-log3 curve is ~100.

You could use the 10 step generator and offset in primaries to create a 10 step with values ranging from 99-1019, which is the maximum value of 10 bit on the wire.

A color space transform could be used to convert bars into Slog/Sgamut3.

https://pro.sony/s3/cms-static-content/ ... 271406.pdf

Good Luck

Maybe this DCTL can help you partially setting that up.
https://procolor.ist/exposure-dctl/

That DCTL is a godsend, thank you! How do I set project up and export it so file contains and is marked full range, please?

The color bars you could take from the generator in Resolve although I'm not sure which colors you desire to have in that space and to what purpose.

I'm just trying to have number of bars with various solid colors so I can have rough visual indicator are there any changes to colors when I later re-import that file into different project (trying to test am I doing things correctly).

1 and 3 are at odds. In 10 bit notation the lowest value on the S-log3 curve is ~100.

Please allow me to rephrase that: I want to end up with file that is marked full range, from 0-1023, and data in it follows curve that is exactly like it is in that PDF you linked to, from 100-ish to 1023.

A color space transform could be used to convert bars into Slog/Sgamut3.

How exactly would you do that, please? Use this for color management or something else?

Capture.JPG (31.6 KiB) Viewed 722 times

I still don't fully understand your goal but if you want basic color bars in a different colorspace you don't need to set up any color management. Just grab the generator color bars, put it in a compound clip so it can be seen on the color page and convert it from Rec.709/Gamma 2.4 to SG3.cine/SLog3. If you want to verify if it is the same data why do you want it to be SG3.cine/SLog3 though? If the value of the patches themselves don't matter? The only way to roundtrip that data back to the original Rec.709/Gamma2.4 it came from can only be done via the inverse of the same transform you used. Meaning if you used DaVinci tone mapping on the first conversion it needs to be used again on the second going back.

... if you want basic color bars in a different colorspace you don't need to set up any color management. Just grab the generator color bars, put it in a compound clip so it can be seen on the color page and convert it from Rec.709/Gamma 2.4 to SG3.cine/SLog3.

Would these be correct settings for that, please?

Capture.JPG (31.6 KiB) Viewed 698 times

I meant with a Color Space Transform effect on the color page or on the edit page.

Keep it simple smarty.

The only adjustment you need to make in the master settings is to enable superwhite/sub black in the monitoring so that the scopes are correct. Leave everything else default.

Use offset to raise the 10-step to 109IRE.

Use a CST to convert the bars to S-Log3.

Export with superwhite/sub black enabled.

This is the roundtripped file, it's identical to the timeline original.

Good Luck

Slog Ref.png (486.02 KiB) Viewed 584 times

Export with superwhite/sub black enabled.

This is the roundtripped file, it's identical to the timeline original.

I trust you exported that file as VIDEO + superwhites / sub blacks enabled, not as FULL, correct? If former than do you still get identical file after roundtrip or you get 100+ area clipped, like I do?

I meant with a Color Space Transform effect on the color page or on the edit page.

So placing test chart generator on timeline in YRGB project with SGamut3.Cine+SLog3 as timeline and output will not automatically convert that chart to SGamut3.Cine+SLog3 on export?