A color managed workflow ensures correct exposure and consistent color when color grading FiLMiC Pro LogV2 by using the X-Rite ColorChecker Passport Video.
FiLMiC LogV2 was released in December 2018. My testing started a couple of months before it became public. These tests have centred around one goal. That goal is to find or develop a new workflow to correct imaging inconsistencies introduced by the dynamic tone mapping active in the iPhone XS, iPhone XS Max and iPhone XR. You can read more about dynamic tone mapping and how FiLMiC LogV2 works in my post What is FiLMiC LogV2?
FiLMiC LogV2 itself does a lot to bring more consistency to Apple’s latest devices. It locks settings down as much as Apple allows, but some of the dynamic image processing continues to cause issues. Hopefully Apple may allow third party app developers to moderate these features, or perhaps even disable them.
Color Grading FiLMiC LogV2
This article assumes you’re running FiLMiC Pro on an iPhone XS, iPhone XS Max or iPhone XR. However, other smartphones, whether iOS or Android may also benefit from employing this workflow.
The first, and most important step in the color grading process is color correction and shot matching. This is the process of correcting exposure, levels and white balance on each shot in a sequence individually. The purpose is to achieve a technically balanced and matched starting point for further grading.
A lut can never do this. This is because a lut is a passive transform that requires a particular input to produce the expected output. If the input is not consistent, or not balanced, the output will be inconsistent and unbalanced too.
Additionally, the challenge of color correcting FiLMiC LogV2 video from the latest generation iPhones is that even the inconsistencies are not consistent. Different lighting conditions and contrast ratios result in levels being mapped differently.
With so many variables affecting how the image is recorded, the only way to correct these variables is to use a fixed reference in every shot.
A Color Managed Workflow for FiLMiC LogV2
Color management while shooting and color correcting video is nothing new. It’s a critical part of every high-end production and post production color pipeline. Precision color reference charts have been used to ensure color consistency since the very beginning of digital video. Especially for cinema and cinema-style production.
Using such an approach when shooting with a smartphone however is quite unusual. I get more than the occasional funny look from bystanders when I’m flashing my color chart everywhere.
The X-Rite Colorchecker Passport Video provides a point of reference for white, black, grey, and the primary, and secondary colors. The reflected values from the color chips on the chart are recorded and can be aligned precisely on your scopes. Armed with a chart and the scopes in your color grading software, you can correct each shot perfectly.
This technique is easy, repeatable, and virtually guarantees perfectly balanced, matched color. It works as long as your scene or subject and the chart are exposed and shot properly.
FiLMiC LogV2 Color Managed Workflow Video Tutorial Part One
Part one shows you how to use the X-Rite ColorChecker Video Passport chart while shooting.
FiLMiC LogV2 Color Managed Workflow Video Tutorial Part Two
Part two shows you how to use the X-Rite ColorChecker Video Passport chart while color correcting.
FiLMiC LogV2 Tips
These are the most important things to remember from the tutorial videos.
Shooting FiLMiC LogV2:
Color grading FiLMiC LogV2:
Following these points will ensure that each shot is correctly balanced into a Rec.709 color space. Further creative color grading can be performed on subsequent nodes.
Challenging Lighting Conditions
There are many lighting conditions when the chart won’t help you. In some cases it’s impossible to light the chart properly. This can happen if there is no white light source, or mixed color temperature light sources.
If the light illuminating the chart isn’t a full spectrum white light source, the color chips won’t reflect the correct values. As a result, the recorded values won’t read correctly on your vectorscope.
Some scenarios are below.
Unfortunately, without a consistent reference in shot, you’re back to manual correction by eye in these situations. The scopes will help, but not provide any absolute reference.
However, there are things you can do in all of the above situations to remove variables that cause inconsistencies. This makes manual color correction without the chart an easier task.
Use a White Balance Preset
Instead of using the white target on the X-Rite ColorChecker Video Passport to set and lock white balance use a white balance preset. If you lock your white balance to daylight (5000K – 5600K), cooler light sources will appear closer to neutral white, and tungsten or warm color light sources will appear quite yellow. If you want a cooler tone, you can use a tungsten preset (2000K – 3200K) and warmer light sources will appear white, and cooler light sources will appear very blue.
In the case of motion picture film stocks for example, different film emulsions are balanced for either daylight color temperatures or tungsten color temperatures. There is no white balance adjustment in camera beyond the choice of film stock. The advantage of using a fixed preset color temperature is you can be sure it’s not changing. Once you correct exposure and levels, you can be sure that any color correction should be fairly consistent because white balance was fixed.
Lock Your ISO
Locking your ISO is a universal rule regardless of lighting conditions. Lock your ISO at a level that gives you an acceptable exposure without too much video noise. I get acceptable results up to ISO 100 with the iPhone XS Max and iPhone XR. Generally the rule is to keep ISO as low as possible.
When ISO and color temperature values are fixed, you only have Apple’s dynamic tone mapping to contend with when correcting and shot matching. This brings me to my final point below.
Shoot the Chart
As long as there is at least some consistent light, you can still shoot the chart. Not to use in post as an absolute reference, but to compare the values of the various chips as they appear from one shot to another. This may help you to manually correct the unavoidable exposure shifts that happen outside of your control due to Apple’s dynamic tone mapping.
A color managed workflow from shoot to post production may seem time consuming. However, with practice it becomes second nature and virtually guarantees near perfect primary color correction and color matched sequences.
It’s worth investing in the X-Rite ColorChecker Passport Video chart. Practice shooting and color correcting a wide variety of shots until it becomes a natural part of your production and post workflow.