Saturday, September 19, 2015

How I color correct my Vlog shots

With this blogpost I am sure I am not adding any original views to the community of videographers out there, especially the pro's among them, but I'm simply sharing my own experience with GH4 shooting Vlog footage.

I am using FCP as my NLE of preference. In every new set of shots, that I usually shoot in one session, I am trying to fix a representative shot first, and then create a preset based on those fixes that I subsequently apply to the remaining shots. This approach usually provides me with satisfactory results; nevertheless, I tend to go over all the remaining shots once more, observe their look-'n-feel that the preset generated, and review their waveforms, and, if necessary, I do some further fine-tuning. I believe this is exactly what most of you out there are doing as well

As the first shot is concerned, I work in non-aggressive iterative steps. The pictures attached hereunder show the sequence of my approach. Since the release of the Vlog-L profile on the GH4, I shoot in that style with +2 stops overexposure. As you can witness in the first screen-capture hereunder, this GH4 profile generates a highly washed out image that has the advantage that its luma waveform is spread between 25% and 75%. 

I first push the shadows to make the luma wave touch the zero line. Subsequently, to my personal taste, I push midtones down as well. Next, I push highlights to touch the 100% line at the top of the luma diagram. Doing this pulls the shadows and midtones higher as well. Therefore, during a second iteration cycle, I am repeating the process by fine-tuning the three exposure components to ensure the final waveform covers the best part of the entire spectrum from 0 to 100% and the resulting image shows the proper tonality and contrast, and above all it is pleasing to the eye. Of course, I don't just do that mechanically only based on waveform shapes, otherwise even computers could learn to do that automatically. At each stage I observe the output frame to get convinced that the result is aesthetically pleasing. 

Eventually, if the white balance of the clip happened to not be to my liking I do correct that in the Color tab of the Color Board, and that after fixing luminosity and contrast in the Exposure tab. In the example below, as can be seen in the RGB parade waveform, the color balance looks acceptable, and didn't need adaptation. Only the Saturation I pushed globally a little bit for reasons of personal taste. 

A sphere look-'n-feel (colorisation) I finally apply using one of many available 'looks' plugin and if necessary some fine-tuning of its parameters, again to my personal taste. In the example shown here, I used mLut by MotionVFX and applied their "metal suit" preset. I could have used anything else for that matter. The result is shown in the last picture in this series.

This has been a simple cycle, quick and dirty, suitable to us, gifted amateurs, who can't afford doing expert colorisation and log corrections with Pro gear like Da Vinci Resolve, regardless whether it's been made available for free by its owners BlackMagic.

Shot in its original state. On the left the Luma and RGB Parade waveforms, on the right the color board for tuning and fine tuning. 
First step pushing down the shadows to touch the zero line.

Doing the same with the midtones to my liking.

Pushing up the highlights, that pulls shadows and midtones higher as well.

Push shadows down again to touch zero.

Same for midtones to my liking.

As highlights moved down too, push them back up again.

As exposure got fixed, do color corrections next. In my case only the global saturation was pushed. The RGB parade shows all three RGB waveforms in balance; no corrections added.

Eventually, a purchased plugin look applied. In this case it was the metal suit look of MotionVFX's mLUT plugin.

Wednesday, September 16, 2015

To err is human, or how Panasonic screwed up the (Vlog) firmware update 2.3 for the Lumix GH4.

From the moment Panasonic's Lumix DMC- GH4 was announced,  first prosumer camera ever to shoot 4K video, it became a legend. More than a year later quite a few good products from competitors emerged to challenge the GH4 with similar and better specs. For instance, Sony managed to pack its sLog2 cinematic profile used by pros in its latest bridge camera, also shooting 4K and offering at the same time up to 1000 fps slow mo! Phenomenal experience! They've been able to achieve such high slow-mo rates by attaching a storage layer back-to-back to the sensor, shortening data travel paths from sensor pixels to storage, achieving extremely short frame storage turnaround; they thus managed to reach spectacular fps rates at HD resolution, unseen for a camera at this price range... Anyways, enough said about Sony... we are discussing the GH4 here. But lets have a good laugh first...

In its initial implementation the GH4 offered various user photo styles of which the so called Cinelike-D was the closest possible to standard log profiles used by the pro's, but not entirely. Beginning of this year they eventually demoed and promised to come up with a firmware update to implement a genuine log profile, the vLog-L that would allegedly offer cinematic quality. A little later they released the 2.2 firmware update that unfortunately, the goodness it offered aside (like the possibility to shoot anamorphic video), it provided no log profile yet. Eventually this option was made available a few days ago (September 2015) on their most recent firmware update release 2.3, but with a caveat. The firmware itself was indeed freely available, but to unlock the vLog-L feature you had to follow a short procedure a part of which was to pay them 99 US dollars! The GH4 fan crowd cursed promptly the Panasonic folks for their greedy attitude. While other suppliers offered log functionality for free, Panasonic chose to earn some easy dough in the process.

By googling around I got to download their GH4_V23.bin update file, not from their support page mind you, but from a mirror site, somewhere out there... In fact Panasonic's download page mentioned something like their servers were under maintenance! You see, 
I made up my mind to install the 2.3 firmware on my GH4 body after all, but I wasn't sure I wanted to pay them 99 bucks to unlock the V-Log. 

Anyways, the firmware update went smooth, and I was soon the happy owner of a GH4 on version 2.3. I even generated the serial number file that I had to send them, that after paying the infamous 99 bucks, they'd have to ship to me a personalised key-file to activate my particular camera. Only then could I in theory select the V-Log setting on the Photo Style option of my camera menu.

As I was strolling around in the GH4 user group on Facebook, my eye caught a posting of someone claiming there was a hack that could render the VLog-L profile accessible without having to pay the 99 bucks. Curious as I am, I followed the links and found out how insane, pardon my French, generous I meant, Panasonic really is. This is how it worked.

If you operate the camera from a smartphone using Panasonic's Image app, besides the remote record function you can also remotely select a shedload camera settings directly on the app. Here's where things went wrong for Panasonic, folks. It appears that when you select the Photo Style settings on the smartphone app, you will also "see" and be able to successfully select the VLog-L option !!! Without a camera activation necessary. Also, once you do set VLog as the Photo Style of choice, it remains permanent on the camera, even if you power it down. In other words, you don't have to operate the camera remotely with your smartphone anymore to achieve a cinematic VLog look. Once selected, it stays selected. 

Pay attention... the "hack" is only valid for the 2.3 version of the firmware and the current version of their iMage app (1.9.5). I reckon they'll be correcting their gaffe in future firmware and app updates, so be careful. If you don't wanna risk accidental loss of this workaround (that's what it is, it's not a "hack" actually), configure your smartphone not to automatically update its apps; you can thus enjoy Vlog on your GH4 for ever, until you decide to get rid of the camera altogether. Naturally, if you change the Photo Style to something else on the camera's own Menu, then you'll have to repeat the remote procedure again to re-establish VLog. Unless you save the style into the Cust setting by pressing the DISP button on the camera, and recall the custom setting each time you want to re-establish Vlog.

The pictures below show captures of the remote app screens about how to select the VLog setting on the smartphone app. In this case this was an iPhone 6 on V 9.1. Click for larger view.

From left to right, Connect smartphone to camera and tap Remote operation, select Q.Menu next, then Photo Style and subsequently select V-Log L. Then save the setting on the camera in Cust.

Finally, here's a shot showing the VLog L look-'n-feel on a test footage and how it was improved to something else on Final Cut Pro via colour correction and subsequent expansion of its luma histogram.

UPDATE: Jeez, they've been lightning fast in pushing a new update (2.4) this time to correct the issue. They really need the 99 bucks, poor sods. I also believe they did their best to make vanish the GH4_V23.bin file from the entire net. You definitely can't find it anymore on their sites, but I believe various mirror sites like Softpedia that initially carried the item (this is where my own download came from) are also disappearing one by one. Some were probably shut down because of the excessive traffic they recently generated. I just checked Softpedia again, and if you select the manual download it still does it... not for long I suppose, as the automatic download re-routes the link to a Panasonic textual statement in... Japanese.

UPDATE 2: A sample short edit of my own test footage in slow-mo 96fps and VLog-L shot on my GH4 and corrected in FCP.