A Beginner’s Guide to V-Log on the Panasonic GH4
Back when it was released in April of last year, Panasonic’s GH4 seemed poised to lead the charge of the 4K mirrorless cameras. Since then, though, the Sony A7S and Sony A7SII have taken over much of that market, offering full-frame sensors, exceptional low-light performance, and higher dynamic range at a similar price point. With the release of V-log for the GH4, Panasonic must be hoping to regain some of those video customers looking for an affordable 4K option that offers flexibility in post. This update is a huge step toward making the GH4 a more attractive option for filmmakers who are already familiar with log profiles, but those of you who haven’t worked with log before may be left wondering what the big deal is. Hopefully, this brief introduction to V-log will help you decide if the GH4 or log profiles, in general, are a good fit for you.
Why Shoot Log?
If you’d like detailed information on Log imaging, News Shooter has a great article that includes a history of the format and an explanation of how Log profiles can differ from camera to camera. For the purposes of this post, though, we’ll boil it down to this: V-log, and Log color spaces in general, are formulas that determine how your camera records color. The Panasonic GH4 has a few picture profiles (other formulas) to choose from, but all of them are meant to be edited and viewed with little to no color correction. V-log, on the other hand, is a low-contrast, low-saturation color space meant to maximize the dynamic range of your recorded image and offer more flexibility for post-production color correction, the downside being that color correction takes time, money, and expertise. Depending on the type of work you do, these may not be resources you can spare, in which case the standard profiles on the GH4 should be just fine. If you’re able to fit a few extra steps in your production schedule, though, V-Log can offer you a much greater degree of control over the final look of your image.
My rental for this test included the camera body, an Atomos Ninja Assassin, and a set of Veydra’s great little Micro 4/3 Mini Primes. You could easily lose some items from that kit to make the package a little more affordable, the phenomenal but expensive Arri follow-focus for instance, but the external recorder is essential. While the Panasonic GH4 will record V-Log 4K internally, you’re limited to 8-bit 4:2:0 color depth. It’s certainly possible to grade that footage if you need to, but if color correction is a priority—and if you’re paying a premium for access to V-Log then it must be—it’s worth the extra cost of an external recorder to utilize the GH4’s ability to output 10-bit 4:2:2 over HDMI. This being a post for beginners, an in-depth explanation of bit depth and chroma sampling is a little more than I have room for here. B&H has a really informative page if you want a more technical explanation of what these specs mean, but, put simply, 10-bit 4:2:2 gives you more color information to work with than 8-bit 4:2:0. This additional information wouldn’t necessarily be something you’d need if you weren’t planning on grading your footage, but if you are then the more data the better.
The awesome and accommodating Memphis Zoo was kind enough to let me shoot some footage in an environment that was a little more dynamic than the focus charts in the Lensrentals offices, and I ended up pleasantly surprised at how much I enjoyed working with the Panasonic GH4. I normally shy away from shooting video with DSLR-type cameras because of the workarounds needed to make them production-ready: XLR adapters, battery solutions, external recorders, etc. The advantage of those cameras, especially with mirrorless ones like the GH4, is that they’re small. I was able to set up, break down, and move around pretty quickly on my own even with the Ninja Assassin attached, certainly a lot quicker than I could have with, say, an FS7. The Atomos Ninja Assassin itself, far from being a cumbersome hindrance like some external recorders can be, was a huge help. The full 1080p screen, waveforms, focus assist, LUT support, and myriad other features make the Assassin one of the best monitors we carry. The fact that it’s a recorder too just feels like a bonus.
The only sticking point I found was that V-Log footage from the Panasonic GH4 can be a little noisy in the shadows, even at native ISO. You could mitigate the problem by exposing a little higher and then bringing your darks down in post. Noise reduction, too, is an option, one that would work especially well if you’re shooting in 4K and finishing in 1080. If you’re planning on doing a lot of low-light shooting, though, you should probably consider a different camera. The Sony A7S, with a full-frame sensor and 3200 native ISO, would be a better choice. Overall, I was really happy with the footage I got from the GH4, but that’s not really a surprise. The verdict has been in on this camera for a while, and I’m not offering any new information by telling you it’s a great low-cost solution for quality 4K. V-Log is what’s new here, and the advantages it offers can be unclear unless you know how to work with it.
The specific processes you’ll go through to grade V-Log will depend on what software you’re using. My editing program of choice is Adobe Premiere Pro CC, so I’m focusing on that here, but I’ll try to keep it as general as possible for those of you who use Final Cut or some other system. In most cases your first step will be to decide on a LUT, or “look up table.” A LUT is essentially a set of mathematical values that translate the colors in your Log footage to a different set of colors. LUTs can be useful for many different purposes, including correcting calibration issues in monitors and converting between industry standard color spaces. If you’re a beginner shooting on a GH4, though, it’s likely that you’re going to be using LUTs as a creative rather than a technical tool. For this purpose, it’s helpful to think of LUTs as “looks,” the differences in which will cause your Log footage to be translated in different ways once they are applied.
“Film looks” are a great example of this type of LUT. They’re meant to be applied to Log footage in order to emulate different film stocks, which is a great way for a beginner to understand the potential creative possibilities of working with LUTs without having to get too in-depth color correcting. The best, easiest to use example of these for the GH4 are James Miller’s Deluts for GH4. I bought my own copy of the set to write this article, so I can say without influence that they look great and are really easy to implement and tweak. The general workflow I’m going to cover here should apply to just about any 3D LUT, though, so if you have a different one you prefer feel free to use it.
My personal workflow for a quick turnaround on edits that don’t need in-depth color correction relies entirely on Premiere CC which, as of a few major updates ago, has LUT support and basic color correction tools built right in. This means, for jobs where I only need to make basic changes, I can keep everything confined to Premiere, saving time and allowing me to stay pretty flexible in the order in which things get done. For more demanding jobs, though, you’ll want to take your final cut to a dedicated color correction program such as Adobe Speedgrade or my personal favorite, Davinci Resolve. Again, though, this post is about basic grading in Premiere, so we’ll stick with that for now.
Once all your footage is in the timeline and cut, you can begin applying LUTs in the “Color” workspace of Premiere. If your Premiere is set to the default settings it should be the middle workspace button in the top center of the Premiere window.
From there you can apply the LUT one of two ways. The first is by navigating to the “Input LUT” dropdown menu of the “Lumetri Color” panel and selecting it from there. The way I prefer, though, is to add the LUT as a “Look” in the “Creative” sub-section. This allows you to control the intensity (essentially opacity) of the LUT you’ve applied.
Once the LUT is applied it’s a simple matter of using your scopes and the sliders in the “Basic Correction” sub-section to develop the look you want. Again, you’ll only want to keep everything in Premiere this way for basic correction, but it’s surprisingly versatile if you expose correctly in camera and get to know how the program works.
In the vast majority of cases, you’ll want to stick to one LUT throughout your project and make adjustments after it has been applied. For this project, though, I used different LUTs for every shot to give you an idea of the range of looks you can achieve. Here’s the test video with file names indicating which LUT from the Deluts set was used to grade each shot. Let me know what you think, and if you have any questions feel free to comment.
Author: Ryan Hill
My name is Ryan and I am a video tech here at Lensrentals.com. In my free time, I mostly shoot documentary stuff, about food a lot of the time, as an excuse to go eat free food. If you need my qualifications, I have a B.A. in Cinema and Photography from Southern Illinois University in beautiful downtown Carbondale, Illinois.