Why we prioritize codec over dynamic range, and dynamic range over resolution.
When it comes to image capture, be it for video production or photography, one spec is more widely referenced than any other. That spec is resolution. From the way people talk about it, you would think that this spec is extremely important. Flat out, barring a few very specific, purpose-driven niche cases, the resolution of your camera is probably the single least important spec on the entire spec sheet.
I am not saying that resolution does not matter at all, because if you drop the resolution of your camera low enough, think back to the old YouTube days of crappy videos that were only roughly 0.5 megapixels (if you were lucky), that was definitely far from an ideal viewing experience. The blocky nature of the huge pixels translated to a resolution that was so low, it was palpable, in a bad way. But once you exceed 1080P resolutions, the returns on higher resolution start to diminish considerably
What might surprise you to hear is that the world’s most widely used camera on the market for any major film production or TV show has a resolution that is barely higher than standard HD. The Arri Alexa Mini has a resolution that tops out at a meager 2.5K (or 3.6-ish megapixels). In a world where even the cheapest smartphone on the planet touts a 4K resolution (9 megapixels-ish), it seems shocking at first glance that the world’s most widely used cinema camera would come in at such a low resolution.
So what are people really after in a cinema camera? What makes them different from a consumer point-and-shoot camera? Why are all these crazy filmmakers shooting on such low-resolution gear?
The answer is that resolution is not much of a concern. The target specs filmmakers are after that matter a whole lot more are color fidelity, dynamic range, and a high-quality codec. When I am personally shooting a film, the color fidelity is basically just a minimum standard that a camera has to meet. This is ironically a standard that camera manufacturers have been losing ground on in recent years, but that is a story for another article. Most high-end gear is pretty decent in this regard (although the OG Pocket Cam from Black Magic Design and the Sigma FP both excel in this department, above the rest of the pack).
The next spec that is extremely important is what codecs you shoot on. Basically, the more compressed an image, the worse the image is. At low levels of compression, you will never notice the difference between totally uncompressed and slightly compressed, but most cameras today are shooting to incredibly highly compressed codecs that crush the character of the sensor, destroy the organic natural noise of the image, and destroy color information in the shadows. So, at Casperson Productions, I insist on shooting either a raw codec, such as Redcode Raw, Black Magic Raw, or Cinema DNG, or we shoot in ProRes 422. Essentially, we insist on shooting to Hollywood standards. The soul of an image can be utterly destroyed by a bad codec. Resolution means nothing if you compress it to death to get there.
Lastly, and arguably one of the most important specs, is dynamic range. If you ever watch a Hollywood film, you will notice that in the expensive films, the sky is always detailed. You can usually even see details in the brightest parts of an image, all the way down to details inside a light bulb in the scene. This is partially because they very carefully light a film set. But the other thing that makes this possible is that the 2.5K Arri Mini has the world’s best dynamic range, significantly better than any competitor’s product on the market. Arri themselves also have a camera called the Alexa 35, which beats even the Alexa Mini with its insane dynamic range, but no one else even gets close.
The first time I picked up a genuine cinema camera after years in film school, shooting on things like the Canon 5D Mark II, I was shocked to find out how bad you could be and still get an amazing image. When you’re working with true cinema cameras, that dynamic range means you can totally botch the exposure by 2 or 3 stops and, in post, press a few buttons, and bam! Magically the image looks amazing. I have never had this experience with a “consumer” grade camera. There are a very small handful of cameras on the market that give you this kind of “get away with murder” kind of quality.
This translates much more to the final video than resolution ever will and is an especially important spec when shooting a wedding film, as things happen fast! And you have limited control over lighting. (not none, we can bring lights, but its not anywhere near to the control you have on a narrative film set) Between these two things, the more latitude a camera gives you, the more wiggle room, the more reliable your image, and the more consistently you can produce top-notch images for every wedding you shoot. It doesn’t matter that the image is rich, 8K, crisp, and sharp if the shadows look blotchy because the camera had such a low dynamic range, the colors are just sickly looking because the codec fell apart, and the color fidelity of the camera was meh.
Lastly, fun fact, most cinema screens only project in “2K”, which is glorified 1080p HD. It’s a crisp, sharp 2K, but it’s not like shooting 12K, 8K, 6K, or even 4K matters that much compared to other specs, especially when it’s not being shown at any of these higher resolutions.
Do we like having 4K? Yes! But do we at all put it at the top item on our list? Nope, not at all, not even close. It’s icing on the cake, but we’re looking for dynamic range, a high-quality codec, and a sensor that has good color fidelity.