Is Sensor Size Everything?

Sony’s Full Frame A7s sensor.

In the photography world, full frame cameras are king. They give a more shallow depth of field, they are better in low light situations, and, oh, 90% of lenses are made for full frame sensors. But is that always the best for video? Over the nearly century and a half lifespan of cinema, full frame hasn’t existed. At least not in the way that the DSLR revolution has taught this generation to think.

Sure, film has had 70mm, 65mm, and Vistavision for years but they have never been easily acceptable or practical in all film setups over the last 100 years. Now it’s even more difficult to get your hands on that film stock unless you’re Quentin Tarantino or Paul Thomas Anderson. And as hard as digital cameras have tried, they still hadn’t come close enough to the film aesthetic. That was until 2008 and the Canon 5D Mark II entered the world. When Canon put the video function on the MkII, they definitely had no idea the impact it would have.

Film stock sizes and digital sensor sizes.

Flash forward nearly 10 years later and where are we? We are saturated with out of focus, “artistic,” full frame videos on Vimeo. Photographers that have made the jump to videography and only think full frame sensors can work. And of course, you have all the online cinematographers that refuse to use anything but a 5D or an A7s. Don’t get me wrong, full frame is great. It’s wonderful if you don’t have much light to work with or if you need to bokeh the heck out of something. But if you’re following someone down a street and you can’t keep the subject in focus then what are you trying to tell the viewer? Depth of field is a wonderful tool in the storytelling war chest and can help direct the viewer to specific objects or areas of the composition.

Now that I’ve babbled for three paragraphs, here’s my point; sensor size isn’t everything. “That’s the title, get to the point.” the reader said as they rolled their eyes. Okay, here. For the last 70 years, a different size of film has been the leader in Hollywood. This size is Super 35mm. Smaller than full frame but still larger than most consumer cameras. Looking at the work horses of the industry, the Sony F series, Arri’s Alexa, and Red’s Dragon. Each of these companies do have large format sensor cameras but they are either not professional enough(Sony A7s), too expensive(Arri 65mm), or not easy to get(Red Weapon 8K Vistavision.)

Red’s Academy 35 Sensor in their Raven.

So, why for years and years has Super 35 been the leader of the pack? There are a lot of reasons but a major factor is focus. It’s common knowledge in the cinema world that the larger the sensor, the shallower the depth of field. Shallow can be great in a stills environment where there’s not constant motion but that motion in cinematography, can be a headache. Cinematographers will often talk about what cameras and lenses they used on a project and when talking about lenses, they will rarely say they shot 100% of a film at a 1.8F/T stop. Trained cinematographers don’t want the subject to breath and lose focus. Aperture helps this but so does sensor size. It’s a lot easier to keep a subject in focus at a 2.8f on a sensor that isn’t a full frame sensor.

Having started professionally on a Canon 7D and getting caught up in the full frame look, I graduated to a 5D. That honeymoon lasted a couple years. It lasted until I picked up a Red Epic and I never wanted to look back again. I of course still use 5D cameras because you use the tool available to you. But I’m tired and frustrated with the look of full frame when it’s done wrong. And if there’s one thing I hope you take away from this, it’s that you shouldn’t be afraid to use a smaller than full frame sensor. Embrace it. Love it. I do.

Arri’s Super35 Alexa Sensor.