6 new J-Log Luts available from JVC [Archive]

Duncan Craig

April 27th, 2017, 09:56 AM

The description in the YouTube video says:

New basic lut is more natural than old lut.
Here is a link of new basic luts and documents.
http://www3.jvckenwood.com/pro/video/...
These include BT709,BT2020 and BT2100_HLG.

J-Log1 exposure is very easy.

Turn on 1D-Lut for LCD and VF.
Spot Meter.Turn to manual mode in menu. Adjust a 18gray is 18% indication. a 90% white is 90% indicate. Very simple to understand.

Histgram: According to menu, a bottom red line on histgram is 0Stop(18%) on default set. So adjust a scean average exposure to a red bottom line. Very nice fnction.

Zebra: According to J-Log1 grapf, 18% gray is 35.9%, 90% white is 66.5%.

GOOGLE TRANSLATION OF THE JVC PAGE:

Page 1
GY-LS 300 CH NEW 3D-LUT FILE for J-Log 1 This manual is a manual about the 3D-LUT file for J-Log 1 of GY-LS 300CH newly developed. Regarding how to apply this 3D-LUT file, please refer to the 3D-LUT FILE for GY-LS 300 CH J-Log 1 Please refer to "How to apply."
Page 2
1. About the newly developed 3D-LUT for GY-LS 300 CH We have newly developed 3D-LUT for J-Log 1 of GY-LS 300 CH with more natural color tone. By using this LUT, you can convert the images taken with J-Log 1 to more natural BASIC LOOK. . For 3D-LUT obtained by converting this natural BASIC LOOK into three kinds of color spaces as below I told you. ① J-Log 1 to Rec 709 Basic A natural color can be obtained in the color space of ITU - R BT. 709. ② J-Log 1 to Rec 2020 Basic Natural color can be obtained in ITU-R BT.2020 color space. ③ J-Log 1 to Rec 2100 HLG Basic (HDR Hybrid Log Gamma) A natural color can be obtained in the HDR color space of Hybrid Log Gamma of ITU - R BT. As a 3D-LUT to provide, for each of these three color spaces for each nonlinear video editing software There are 6 types in total, two for Day Light and Tungsten, and for display (. Cub), these three We prepared three kinds for allround which can be used for both DayLight and Tungsten for color space. For these 3D-LUTs, refer to Table 1 on the last page. As for the application method of this new 3D-LUT, it is possible to use from Please refer to "How to apply 3D-LUT FILE for GY-LS 300 J J-Log 1".
Page 3
2. On color space conversion of newly developed 3D-LUT This time, we will explain three color space conversion newly developed. ① J-Log 1 to Rec 709 Basic Convert J-Log 1 to Rec 709 color space. It becomes a natural coloration on the monitor of the Rec 709 standard. The gamma is higher than the gamma of the Rec 709 standard by a maximum In order to express the dynamic range of J-Log 1 of 800%, the high luminance part has a gentle characteristic. ② J-Log 1 to Rec 2020 Basic Convert J-Log 1 to Rec 2020 color space. Please watch it on the monitor of Rec2020 mode. As shown in Figure 1, the color gamut of J-Log 1 has a wide color gamut with a cover ratio of Rec 2020 of 80.3%, and the book By converting to Rec2020 with LUT, it is possible to reproduce the color of wide color gamut which Rec 709 can not obtain. For example, the color reproduction of short-wavelength light-emitting objects such as colored lamps is improved, and in the range of Rec 709 The body can obtain the same natural color tone as J-Log 1 to Rec 709 Basic of ①. Fig. 1 J-Log 1 color gamut (Gamut when J-Log 1 of red line is GY-LS 300 CH) On the monitor of the Rec 2020 standard, the gamma is maximally higher than the gamma of the Rec 709 standard by the dynamics of J-Log 1 To make it possible to express 800% of the clarity, the high luminance part has a gentle characteristic. When converting to Rec 2020 using this LUT, the camera side shoots with 4 K or Cinema 4 K (C 4 K) Grading in near editing software etc is handled with high precision floating point and final writing is over 10 bits It is recommended to do it in format.
Page 4
③ J-Log 1 to Rec 2100 HLG Basic (HDR Hybrid Log Gamma) J-Log 1 is converted to HLG (Hybrid Log Gamma) color space among Rec 2100 of HDR standard . Since the color gamut standard of Rec 2100 is the same as Rec 2020, color conversion in this LUT is the same as Convert J-Log 1 to a wide color gamut of Rec 2020 with a covering ratio of 80.3%. If converted to HLG with this LUT, Rec 709 A wide color gamut can be realized which could not be obtained with. Also, since the tone becomes the characteristic of HLG, the HDR effect of HLG You will get fruit. In order to obtain the HDR effect using this LUT, always be sure to monitor the HLG mode compatible monitor Please watch it with. The gamma characteristic of J-Log 1 and the characteristic of HLG are the same as the input maximum range of the HLG standard "Input 12 2: HLG 12) "when the" input 2.4 (Fig. 2: HLG 2.4) "part is set to 100% white reflectance, it approximates the HLG characteristic . As described above, J-Log 1 has characteristics very similar to those of the HLG standard, so this LUT can not correct gamma correctly This is done only in the section, and it has become the specification which suppressed image quality degradation of gamma conversion as much as possible. Figure 2 J-Log 1 and HLG characteristics When converting to HLG HDR using this LUT, the camera side shoots with 4K or Cinema 4K (C4K), and non Grading in linear editing software etc. is handled with high precision floating point and final writing is over 10 bits It is recommended to do it in format.