Notes on Cinematography: DSLRs, Color, and Light.

by andrewcagle

I enjoy documentary film in large part because of the stories. I also love the social sciences, current events, and topics of faith. Much of the time I write about these things as a way to share my thoughts and views on various subjects. I also enjoy filmmaking because of the art and science it holds. It’s a craft. For someone who is a sponge for knowledge, there is much to learn and explore in the world of digital storytelling. For a change of pace, I am offering some notes on capturing images on DSLR cameras.

Directors hire cinematographers for their eyes. They search for someone who can capture the images needed to best tell their story. There is a lot of art and personal preference in photography. There is also a lot of science. This is compounded even more by the advent and takeover of digital technology. Here are some notes, preference, techniques, and advice from someone who has spent the past couple of years practicing cinematography on DSLR cameras.

When it comes to the most useful and unused tool in cinematography, filters are it. Filters are a great way to add control to the image you are capturing. For a long time, I didn’t use filters or think much about it. Coincidentally, I haven’t observed many younger filmmakers making use of them either. The convenient thing about SLR lenses is that filters are abundant and affordable (compared to matte box and cinematic options). UV, ND, and polarizing filters should be a staple in any filmmakers toolkit in order to deal with regular adjustments needed for any location. For South Sudan, these allow me to work through having to shoot in the harsh African sun, dust and haze during dry season, and unwanted reflection and glare. Options like warming and cooling filters can help stylize your shots or correct the temperature of a scene to fit the story.

Much of of good cinematography is about properly lighting a scene. Here in Africa I use natural light 90% of the time. I also prefer it. I carry a small battery powered LED light and a white umbrella. When possible, I use it to front light my subject during an interview (this can be very useful with dark skin tones). Normally I just work with the location and angle of the sun in the sky to get the best lighting. Essentially when working on a small crew or alone, especially in the field, there can be little control over lighting. Even so, filters are an important tool on well lit sets in order to stylize and achieve a look, soften skin tones, or control exposure or glare.

Over the past two years as DSLRs and shortcut color correction/grading software like Magic Bullet Looks have made a rise, there is a growing trend of shooting flat while filming. The reasoning behind this is to give greater dynamic range and latitude in post-production for color grading. I have tried this technique and am not an advocate. I’ll explain why. I always follow the practice of getting as close to the final image as possible during initial capture. Proper color correction and grading can do wonders to improve and finish your film, but shooting flat or slightly overexposed means you have to rely more heavily on software and computers to achieve the desired final image. In the case of DSLRs, shooting flat does not actually offer any true flexibility in post, nor does it achieve a greater dynamic range. The only way to do this is shoot at the highest bit rate possible for the least compressed image.

One aspect of DSLRs commonly overlooked is the format and color depth. Digital formats still lack the amount of color depth and light data in comparison to film. So far, the only camera that has proved to compete with film is the Arri Alexa. Cameras like the Canon 7D (which I use) record in a 4:2:2 YCbCr chroma  subsampling ratio without the option of a full, uncompressed 4:4:4 RGB sample. There is also a great difference in dynamic range between the two cameras. The Alexa captures the same amount of light as film, a full 13.5 stops. The 7D is closer to 7 or 8. The more detail and data that is captured at first, the more flexibility in post. Nick Paton, ASC explains, “the Alexa responds very well where as the 7D footage fails in highlight exposure detail and it’s codec compromises it’s ability to be pulled up in the darker regions.” The 7D still records using an AVCHD codec, and can’t compete with the 2k resolution of higher end cameras. These factors allow DSLR footage very little flexibility in post. It just can’t be manipulated in a way that provides great accuracy for drastic changes to an image while retaining image quality and precision in grading. This all hinges on the ability of the camera to capture the greatest amount of detail in the highlights and shadows.

This is why, for those of use shooting on DSLRs, I advocate an approach during principal photography that works to achieve an initial image out of camera that is closest to the desired end product. If you are working overseas, or shooting in an environment where DSLRs are a wonderful tool, this should be taken into consideration during the production stage.