GH4 Leeming LUT One – the best LUT for the Panasonic GH4

Thomas Smet said:
In theory yes you are absolutely right. Starting with any image processing with a raw signal will always be the best. In practice however that isn't always true when it comes to noise reduction. Cameras have very limited processing power and they need to de-bayer, scale and process the image 60 times per second. In the case of the GH5 that is 60 times per second at an over 4k resolution. That is a massive amount of processing power that even a top quad core computer can struggle with. The NR done in camera is nowhere near as sophisticated as that in a program like Neatvideo. Neatvideo is painfully slow for a good reason and that is how much time it can take to deal with noise reduction. NR is one of the most intensive tasks you can do in image processing. Neatvideo is also designed to compensate for some of that image compression on high noise material.

The engineers at Panasonic are some amazing people but they can only use the processing power available to them and speed and stability are an absolute must.

Just like anything else we do the answer is really it depends. It can depend on a lot of factors and having used Neatvideo a lot myself over the past few years I can tell you it does a really good job on -5 NR material. Of course if you shoot ISO12,800 and have a ton of noise use are kind of screwed either way. The in camera NR is going to create such odd blotchy artifacts I would honestly take my chances with Neatvideo making sense of the H264 macro blocking.

In the case of realistic ISO levels 200-1600 the macro blocking damage at -5NR will not be enough to harm what Neatvideo can do. If one is shooting at insane ISO levels then maybe, maybe in camera might do better but I think it is important for each person to test it out. Any NR is a massive alteration and damage to the original video. Which one is better is not the right question here and it has more to do with which one looks less weird to each person.
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Exactly this. Well said Thomas :)
 
Compatibility. So that the GH4-GH5's limited dynamic range would match (fit inside) the same curve used with Varicams.

Practical benefit of this choice ... almost none. Using Varicam LUT's looks terrible (completely different color science.)

Practical weakness of this choice ... almost 30% of the available bandwidth is wasted. Less of an issue with 10-bit, but a severe crippling of 8-bit.
 
What Joe said :)

I wish Panasonic would create a log profile in camera which uses the full 10 bits of signal range, without regard to matching the full Varicam log, or transposing it into the full bit space to better utilise the values.

Anyway, at least in 10 bit it works well :)

Cheers,

Paul :)
 
visceralpsyche said:
I wish Panasonic would create a log profile in camera which uses the full 10 bits of signal range, without regard to matching the full Varicam log, or transposing it into the full bit space to better utilise the values.
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But this makes the LOG profile specific to the camera you are using, as the LOG curve would be different for each camera's dynamic range.

The GH5 has a dynamic-range of 12+ F-stops. The GH6 might have a dynamic-range of 13+ F-stops. The GH7 might have a dynamic-range of 14+ F-stops.

This means that each camera would have to have it's own LOG curve.

The current V-Log L curve is a sub-set of the Varicam LOG 16 F-stop curve, so any camera with 16 F-stops or less of dynamic-range works within the Varicam LOG curve.
 
TheDingo said:
But this makes the LOG profile specific to the camera you are using, as the LOG curve would be different for each camera's dynamic range.

The GH5 has a dynamic-range of 12+ F-stops. The GH6 might have a dynamic-range of 13+ F-stops. The GH7 might have a dynamic-range of 14+ F-stops.

This means that each camera would have to have it's own LOG curve.
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That's already the case, in reality, there is no industry standard for LOG curves. Every manufacturer and camera requires LUT's crafted specifically for the proprietary LOG profiles used in that model. Since the main purpose of these distinctions in LOG profiles is to promote the advertised DR claims of the manufacturers who market them, this practice is not likely to change.

If future GH models are produced with increased DR, it would mean they have lower noise in the shadow region, allowing additional stops of detail to be discriminated in the near-black end of the scale. The V-log L profile would be incapable of accomodating that improvement, as its additional range extends beyond the 80 IRE limit of the GH4-5, and has no room for additional stops of shadow range. A new, incompatible LOG curve would be required for that purpose.
 
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TheDingo said:
But this makes the LOG profile specific to the camera you are using, as the LOG curve would be different for each camera's dynamic range.

The GH5 has a dynamic-range of 12+ F-stops. The GH6 might have a dynamic-range of 13+ F-stops. The GH7 might have a dynamic-range of 14+ F-stops.

This means that each camera would have to have it's own LOG curve.

The current V-Log L curve is a sub-set of the Varicam LOG 16 F-stop curve, so any camera with 16 F-stops or less of dynamic-range works within the Varicam LOG curve.
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1. So what? :-) Seriously, so what? Who cares if you have one more LUT if it means unlocking the full capability of your camera instead of chopping it off at the knees. The GH-series is popular enough that every notable tool supports it. (For example, FilmConvert had a profile out almost at launch.)
2. The Varicam gamma curve works...but color transforms baked into the LUT are not compatible at all. The different cams have very different color science, and the Varicam LUT is visibly off for both the GH4 and GH5. (Just load a color chart and look for yourself.)
 
Yea, the Varicam-compatibility excuse is really lame. If tons of shooters like Luke Neumann, Paul Leeming, Daniel Peters, etc, can all manage to make and sell LUTs all by themselves, Panasonic can most certainly afford to make a bespoke LUT for each camera.
 
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