Visceral Psyche Films has released Leeming LUT One for the JVC GY-LS300 video camera. It is available for download here:
Leeming LUT One is well-known in the Panasonic GH4 community as one of the best solutions for achieving consistent, high-quality images utilizing the camera's maximum dynamic range. This LUT is calibrated for use with the LS300's J-Log1 profile to give your image the best starting point for further grading and esthetic refinement. In addition, Leeming LUT One may be used to match LS300 footage with the GH4 and other supported cameras.
To develop this LUT, I worked with Paul Leeming on testing and evaluating a wide range of LS300 footage, taken in both natural and artifical lighting conditions. The results of this collaboration satisfy all of my requirements for a standarized post-production workflow that makes full use of the dynamic range of the LS300's J-Log1 profile. It is provided in a format compatible with a wide variety of editing and grading tools and can be flexibly integrated into virtually any type of post-production workflow.
You mean that it can be bough for 15 EUR at certain URL.
Can you explain why someone need to buy LUT?
What exact camera settings are fixed at J-Log1 to allow any meaningful LUT usage?
LUT is developed to bring the camera's recorded image to a standard, Rec709 baseline image that retains all the dynamic range while fixing any colour errors and minimising noise. This LUT is also designed to make the image feel as filmic as possible within the Rec709 parameters. In other words, the intent is not only to make a proper Rec709 output, but have it feel closer to celluloid film than a harsh video output
I also have issue with this marketing statements.
The downloadable LUT package provided by JVC for the LS300 fails to provide a high quality conversion of J-Log1 footage into REC 709 color space. The results JVC's LUT produces are so over-saturated that I found it useless as a starting point for further grading of J-Log1 footage. Leeming LUT One provides a standardized J-Log1 post-production solution that I have personally evaluated to meet my own requirements. The costs of production and distribution of this LUT are the sole responsibility of Visceral Psyche Films. I participated in this collaboration with no expectation of financial compensation or sharing of those costs or proceeds.
In J-Log1 mode, all LS300 camera process controls are preset to standardized settings, leaving only exposure and white balance as user adjustments. All automated exposure features are disabled, requiring fully manual exposure settings. A built-in 1D display LUT can be enabled to provide an approximation of REC 709 color values on the viewfinder and LCD screen, but this LUT is not available for post-production processing of the footage. As with log profiles on other cameras, J-Log1 footage is not intended for direct viewing on a REC 709 display such as an HDTV, it requires color-correction with either a standardized LUT or custom grading. Leeming LUT One is the best solution I have found for this purpose.
The downloadable LUT package provided by JVC for the LS300 fails to provide a high quality conversion of J-Log1 footage into REC 709 color space. The results JVC's LUT produces are so over-saturated that I found it useless as a starting point for further grading of J-Log1 footage.
It means that you can show measurements of color difference using standard charts between build in LUT / rec 709 ideal and yours?
@Vitaliy_Kiselev No, that would require proprietary technical documentation of the sensor colorimetry and J-Log1 tone curve used in the LS300, which JVC has not disclosed.
What we can do is to shoot footage of industry-standard color charts (e.g. X-rite) and calibrate those images to Rec 709 standards. That is what enables us to match both LS300 and GH4 footage independently of manufacturer specifications.
No, that would require proprietary technical documentation of the sensor colorimetry and J-Log1 tone curve used in the LS300, which JVC has not disclosed.
This one I do not get, I asked for final image measurements and comparison.
What we can do is to shoot footage of industry-standard color charts (e.g. X-rite) and calibrate those images to Rec 709 standards. That is what enables us to match both LS300 and GH4 footage independently of manufacturer specifications
Cool, this is close to that I ask.
Can we see color difference measurements between standard JVC LUT, ideal image (math), and your LUT usage result. All on standard chart.
@belfryman Not sure what you mean by "pulling it down under 75". The LS300 Leeming LUT is designed to be used first in the chain of grading modifications, as a generic color correction from J-Log1 to Rec 709. It is provided in .cube format, compatible with a wide variety of editors and color correction software.
For Adobe After Effects users, a quick way to evaluate the Leeming LUT is to use the built-in effect: Utility/Apply Color LUT. Here are a pair of frame grabs of a shot, in original J-Log1 format, and with the LS300 Leeming LUT applied: Note how both the highly saturated hues of the color chart and the natural shades of the sunlit landscape are rendered with accurate color values.
@LPowell sorry, I mean following the JVC instruction to set the exposure below 700mV before applying their LUT, that's made all the difference for me, I was just applying the JVC LUT which just meant horrible blown out footage. When I follow the actual instructions it comes out pretty close to this LUT to my, very unscientific eyes! But very nice to have the combination and have it pegged throughout to the right kind of level.
My experience with J-Log1 exposure is reflected in the instructions that accompany the LS300 Leeming LUT. I use the histogram to gauge the best ETTR balance of highlights versus shadows, and the zebra (set at 100%) to show which highlights fall in the superwhite exposure range (100-108%). I abandoned the camera's spot meter after finding its percentage readings (up to "800%" in J-Log1 mode) provided no reliable indication of where highlights begin to blow out.
While the J-Log1 gamma curve is not as extreme (i.e. retains moderate contrast levels) as the log profiles in other cameras, it is quite flat throughout most of the IRE scale. This makes the Leeming LUT work consistently across a wide range of exposure levels. The J-Log1 curve does appear to roll off a bit in the superwhite region, so for the finest highlight detail, I'd recommend exposing below the zebra threshold.
@belfryman Make sure your video editor properly recovers highlights in the superwhite (100-108%) range. LS300 footage is interpreted as Rec 709 studio swing video (i.e. 8-bit 16-235), even though J-Log1 records highlight details beyond 100% white. In Adobe After Effects, I often reduce luma gain to 91% in order to recover the superwhite highlights.
@LPowell Success! I don't know what was going on with the 100% clipping but I am now getting footage that isn't clipped at 100% now. I finally sussed out the histogram, cos not needed to set it myself before, used the zebras to set the histogram to. Now I think I have something where I know pretty much what's going on exposure wise. It's a bit difficult to tread the line between the 100 and 108 without risking blowing out because the histogram is so small on the LCD and I bought a 2nd hand zacuto evf pro which has no histogram at all, so I'm going to pretty much leave the 100-108 as error margin territory, and work off the zebras on the zacuto which are matching well with the on camera. I think I may now be safe to shoot j-log and just pop on your lut and good to go. I hope!
@LPowell This will probably be stating the obvious, but I just got the clipping at 100% again after, unfortunately, exposing to the right and burnt out a load of stuff. I was shooting 1080 422, I think this is where I'm getting the problem even though I'm shooting j-log, it clips at 100%, in 4K it has been doing the expected not clipping to 108%. I'll have to find time to test this but hadn't seen the 100% clipping for a while and just moved back to shooting 1080 for the colour space.
JVC log seems to have an extra gear
@DrDave That was a clueless test of what happens when you misuse a video camera, but it did show how bulletproof the LS300 is. In Jlog-1 mode, it defaults to ISO 800, but can be set as low as ISO 400, so 3200 isn't that bad. In practice, ISO 1600 is the max I'd recommend, assuming you're prepared to use NeatVideo on it. But with GH2 and GH4, ISO 800 is all you can reasonably expect.
I was impressed. Thinking seriously about this cam
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