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.
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.