@joonas_t

I guess if the problem appears in specific conditions (sky gradients, for instance), one can get way working on these clips only, because many scenes won't show this limitation, hence no need for a particular/special/time consuming work?

@RKM

Isn't a LUT in camera in called "Photo Styles" ? (or am I misinterpreting your point)

@labalbi The autor of the video worte this:

"As I'm currently in Bangalore (India) I decided to make a very quick V-LOG L test to check out the possibilities of the new picture profile. Especially as I'm going to Agra this weekend to see and shoot the Taj Mahal.

This is a very rough shoot early in the morning (around 5am) with low availability of light and a lot of fog. The first shots are definitely underexposed and you see a lot of noise. My experience so far: You definitely need to overexpose by 1-2 stops to reduce noise. Highlight might blow out but the roll off looks ok.

Gear: Panasonic GH4 Sigma 18-35 1.8 Panasonic 35-100 2.8 Metabones Speedbooster

Camera Settings: Picture profile: V-LOG L Sharpness: 0 NR: 0 ISO: 400/800

Color Correction/Grade: Lumetri: Basic LUT: ALEXA_Default_LOGC2Rec709, Creativ: James Miller LUTs "Leeds" (set to 45%)" Timo Hurtig

Any other questions make to the author of the video on vimeo.

@joonas_t

Noise in the shadows or banding is bad data, but macro blocking might be just bad interpretation.

Noise is not "bad data", it is real. Concealing the noise with macro blocking is not merely "bad interpretation", it is irreversible data loss. A 12-stop dynamic range is of little value when the bottom four stops are crushed into oblivion.

V Log L as with Slog 3 works better under 10-bit. Period. But thats not to say as @shian correctly states you can still make an 8-bit image look good.. Whether its V log or not. Remind yourself this is a very cheap camera which does a lot of things really well.

Its been an exhausting few weeks producing two films and doing an ambassador shot at IBC. Its not easy, its hard work and you can't please everybody all of the time, that Ive learned. Im absolutely shattered after taking my daughter on a 12 hour drop off trip to university, she's doing Filmmaking and Im very proud of her. Family comes first. V Log stuff is currently at the back of my mind.

Although many have pointed to 8 bit internal being the issue, the real issue is Panasonic only using around 2/3rds of that range in some feeble attempt to match Varicam response. If the entire 0-255 range was used, many of these problems would be alleviated.

Using only 3/4 of the available code values amounts to throwing out half a bit. Sure, it's dumb, but it's not the cause of all the problems. If Panasonic shifted the middle grey value up to make full use of the V-Log curve, banding in the shadows would be improved. But banding in the midtones and highlights wouldn't be any better. You still have the problem that the V-Log curve is too steep and the gamut is too large. V-Log packs too many stops into a given range of code values. The color space is simply not optimized for 8-bit encoding and the dynamic range of the GH4.

Panasonic made some rather bizarre decisions. They wanted to capitalize on the cachet of V-Log and camera logs in general, while not diluting the Varicam brand. So they called it V-Log L ("Lite"), to distinguish it from V-Log. But they wanted to make it fully compatible with V-Log. So it's exactly the same: same curve, same gamut, same middle grey level. Panasonic missed a grand opportunity to create a V-Log L that was actually lighter and better optimized for the cameras it would be used on.

Canon deserves a lot of credit for its C100/C300 Canon Log, which is very well optimized for those cameras and for 8-bit encoding. Sony has also done alright with S-Log 2 on cameras like the a7S and a7R II. S-Log 2 is not optimized for 8 bits, but it's a lot more efficient encoding than V-Log. And on those Sony cameras you can select the gamut independently from the gamma, which helps a lot.

It is my contention that the GH4 Standard photo style is already well matched to the GH4's dynamic range and 8-bit encoding. It's just not a great color space to do color correction in. But that problem is solvable: transform from Standard into some log or log-like space for working.

My hypothesis is that anything you can do with V-Log L you can do better with Standard, if you expose correctly and do the right transformations. I guess I just need to get my hands on a GH4 to do the proper testing.

Any GH4 owners in the south SF bay area?

And by the way... macro blocking is only located in monochromatic areas, so to fix it you can just re-create the hue channel alltogether with a solid or a gradient colour layer and put it to hue blending mode. Just mask out areas that you don't what to re-create. Here is an example of macro blocking correction in after effects with the screenshot @aaronchicago provided.

Sometimes with a bit of luck you might be able to recreate the luminance channel too (luminance blending mode) and animate it to fit the clip to fix banding issues.

@joonas_t

Noise is not real, at least I don't see it in real life, so it must be bad data from the sensor...

While you may not have seen it with your naked eyes, noise is an inherent aspect of the quantum mechanical nature of both light and the image sensors we use to capture it. All sensors have a property called "quantum efficiency", which indicates the percentage of captured photons that produce measureable charge in the image sensor's circuitry. This percentage is purely statistical - in an individual image, there is no way to distinguish genuine detail from random quantum fluctuations. Noise exists at consistent levels throughout an image, but as the intensity of light diminishes in shadow areas, genuine details recede while the noise remains constant. If you want to capture the sensor's broadest dynamic range, it's important to preserve as much shadow detail as practical, so that you have accurate data to use with noise management tools in post.

sorry, updated the link

https://www.flickr.com/gp/76276262@N04/3X2a0U

Thanks @shain.

I am also wondering if and to what standard people are calibrating their monitors too? I found in the past this led to banding in skin tones from my GH2. After a re-calibration the banding was gone. For better or worse I use the Dell Premiere color U2410 monitors (wide gamut, I think) calibrated with an X-rite Eye Pro, to the rec. 709 standard. I believe this is the best way to view my footage for HD production, but, am no expert. They were all ebay purchases, but, do match after calibration.

Is it safe to say that V-Log Saturation and Noise Reduction should be left at 0?

@GoodAlwaysWins,

I think you mean "Sharpness" and "Noise Reduction"