Kine LOG explained by Dan Hudgins

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  • #697

    Arooj Azam

    KineLOG is a set of curves that vary with the ISO curve setting in the camera.

    Their ISO menus are confusing, there should be two menus, one for ISO curve, the other for analog gain boost, 1x to 64x.

    Anyway, the 3D-LUT in each shot folder changes when the ISO curve changes, so if you change the ISO curve when shooting, the same 3D-LUT cannot be applied to all footage and get ISO normalization so that 18% gray comes out to about 470/1023.

    KineLOG is Cineon ™ so works with film scan input, like LOG DPX.

    Arri lowered the 18% gray point from 470/1023 to 400/1023 which makes the ISO shift, like from 500 to 800, so Arri LOG-C is not the same as Kodak Cineon ™ standard.

    I made a KineLOGC look group that can be added through a USB drive in the cameras side port. That is only 800 ISO curve now but can work at higher ISO with the analog gain 1x to 64x added. That is a close match to ARRI LOG-C, at least as far as luma, I tested it with the ARRI 3D-LUT generator on their web site and it seems to work OK, with some saturation added after conversion to Rec.709 by the ARRI 3D-LUT *.cube file (Arri makes different cube files for each ISO in their camera, but their 800 table seems to be close enough to use with the KineMINI 2K camera I tested with).

    I also made a new look group KineLOGF which is a revised version of KineLOG with some adjustments to the shadow end to be closer to a film scan.

    Anyway, yes if you convert the footage through the shot folder 3D-LUT you get something close to Cineon Film Scan LOG, 90 points per stop, black level at 95/1023, 90% about 685/1023, super white varies with the camera ISO setting ranging between 685/1023 at 80 curve to 1023/1023 with ISO 1280 with 2560 curves. So if you want the full log range you need to set ISO 1280 KineLOG curve. Past ISO 1280 a shoulder curve is applied so there is no clipping and you hold more stops in the highlights.

    For night shots, setting ISO 1280 curve and analog gain 1x to 4x works best maybe, that gives you EI 1280 to 5120. If you shoot with more analog gain you need to lock the camera down as de-noise works better if the camera is not moving, just the subject.

    Under 60Hz lighting you can set the shutter to 288 degrees for 24fps without flicker if there is little motion or the motion is in the distance and the camera is locked down to get less noise, like shooting at EI 20480 in very low light (that’s about the limit, but doubling the shutter adds another stop without extra gain.)

    Test things to see what works, if you go to H.264 release formats, you need clean footage, so some de-noise is normal for working with raw cameras as they don’t de-noise internally in the same way as H.264 recording cameras. You can also grade from the linear 12 bit data without the 3D-LUT or Cineform, which is what I do with my software, just read the data from the DNG and ignore the header values.

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