Ryan E. Walters, Cinematographer

Cinematic Excellence at 24 Frames a Second

The Power Of Camera Filtration

As a cinematographer, one of my responsibilities is to craft the image to reinforce the story I am helping to tell. While lighting, framing, and camera movement are often the first tools that come to mind, an often over looked tool at our disposal is camera filtration. Unfortunately, with the rise of the digital age, and the power of our grading software, filtration at the camera level is not as popular as it once was. While I can appreciate the fear that some directors and productions have of baking in a look, here is why I think in camera filtration can be a powerful tool, and why you should be considering it for your production.

A Very Rough / Crude Diagram ... ;)

Why Camera Filtration Is Better Than Post Filtration
There are two fundamental reasons (and one side benefit) why camera filtration is better than post filtration. The first fundamental reason is demonstrated by my non-technically accurate diagram above. The numbers I have used are completely arbitrary, and are only there to communicate the big idea (so don't get hung up on them). The concept that I am demonstrating with this diagram is that an element of "organicness" and nuance is lost at each stage of the process.

In Stage 01, the "real world," the image is at its most organic, full of rich detail and nuance. The possibilities are endless. The first thing that comes into contact and shapes the feeling of that image is the camera filtration, Stage 02. The careful selection and use of filters can reinforce the underlying tone of a scene. Because these filters are physical in nature, they react with the infinite amount of "data" that is coming at it in the form of light, shadow and color. It then passes this "data" onto the next part of the optical path, the lens, Stage 03.

Recorded in ProRes 422 HQ via the Ninja 2

The characteristics of the lens take the "data" given to it from the filters, and again shape it according to its own unique personality. This image, one that has gone through two "layers" of molding, is then projected onto the camera's sensor, Stage 04. The camera sensor gathers all of this "data" and passes it onto the A/D Converter, where the infinite number of values are baked into a finite number of values in the form of a digital file, Stage 05. Raw or not, this file no longer has the same amount of values of light, shadow, and color that existed on set in front of the camera. By definition they are limited.

I have had the opportunity over the years to work with some talented colorists who have done an amazing job at grading my footage, breathing new life into it. But no matter how talented they are, they are working within the limitations of the footage that is given to them- within limited possibilities. They can, and often do, mimic many camera filters well. However, they will never be able to completely replicate what happens between the interplay of light, shadow, and color before it gets recorded by the camera. Furthermore, by using camera filtration, you open yourself up to the possibilities of finding the happy accident. These same happy accidents do not occur the same way in the clinical environment of the grading suite. Below is an example of a shot I made when I was playing around with heavy ND, a polarizer, & Coral filters on the Red One MX with no IR filtration. It is a look that I like, and wouldn't have thought of trying to create in the grading suite.

Red One MX + Red Pro Zoom + 2 Coral (Schneider) + 1.5ND (Formatt) + Polarizer (Schneider) [w/o IR filtration]

The second fundamental reason why I see camera filtration as better than post filtration is clarity and specificity of vision. The more clear and specific the vision, the more powerful the story. So if a specific look is called for in a production, why not support that vision and look by creating it in camera? As the effect is created in camera, you can get real time feedback on the success of the look, and do everything you can to reinforce what you are saying with that image (i.e. set dressing, wardrobe, etc.).

If, on the other hand, you want to play it safe, and leave all options open until the grade, you are essentially saying that you do not know what it is that you want to say. That will result in a weaker story, and weaker images. For example, what if in post, after much deliberation, you descide that you want the grade to reflect a rich, warm, almost monochromatic look, but the shots contain a lot of vibrant cool tones in them? While you can pull back the saturation, selectively adjust the offending colors, and then slap a warm grade on it, that image will not be as strong as one that was originally designed, set dressed, and filtered that way.

Blackstar Warrior - Grade By Darren Griffiths
[Red One M + Cooke S2/S3 & Red Pro Primes w/ 1/4 Coral & 1/8 Classic Soft]

As much as I think that camera filtration is better than post filtration, I do not see it as an either or mentality; it is a both/and. This leads me to the side benefit of in camera filtration: more time for creating and shaping the image in post. As I said before, a talented colorist can breathe new life into an image. If they are given an image that is strong to begin with, they can take it even further, making the image stronger, therein further reinforcing the story being told. This in turn helps to keep the budget down, and to produce results quicker than if they had to spend that same time fixing the image before even getting to the manipulation stage (and this is a crucial point for Indy productions that have limited funds and time in the first place...).

Ok, great, in camera filtration is preferred, but where do I start? The first place to start is with experimentation. You are never going to know how something works until you see it and test it for yourself (which is an importent step of preproduction). Go to your local rental shop and try out whatever peaks your fancy. If you want to see some examples of filters in action, you can check out this Filter Comparison Video I did, or you can watch the three hour Filter Expo put on by AbelCine.

Tiffen Red Enhancer / Clean / Tiffen Green Enhancer (Filters Provided via Shawn Nelson)

Here are some ideas to get you started:
- Low-Contrast: Reduce the contrast of the image. Could be used for exposure control, or to help reinforce the pastel nature of a scene.

- Fog Filters: Reduce the contrast of the image by allowing the highlight to bloom. When combined with a touch of overexposure, it creates a very ethereal look.

- Coral Filters: Warm up an image. Use a #5 to get the sepia look, and add Fog #3 and a Chocolate filter to get an old aged/faded look.

- Polarizer: In addition to enhancing the color of the sky, if you set your white balance to tungsten, use the polarizer at full strength, and a touch of ND, you can get a day for night look. (It really helps if you have lights on in the scene (car, house, lamps ...).

- Diffusion: A great way to remove wrinkles and other blemishes. One of my favorites is the Hollywood Blackmagic, but there are many others, such as Classic Soft, Promist, etc.

- Attenuators: These filters are a great way to control the exposure of the sky to the foreground if you are going handheld, as the transition is gradual and hard to notice.

- ND Grads: Great way to control exposure, however, you'll want to avoid lots of movement, as it is easy to reveal the transition.

Enhancers: Enhance the color of one color channel, as in the example above.

- Coral Filters + Classic Soft: Mix and match to replicate the look of older Cooke S2/S3 lenses. (On Blackstar Warrior, I used a 1/4 Coral + 1/8 Classic Soft to get a close match when my second set of lenses had to be a set of Red Pro Primes.)

Do you use filters or prefer to create your look in post? What are some of the filters you use and why?

Until Next Time - Get Out There And Shoot!
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