Camera Sensors, Does size matter?

One inch, MFT, APS-C, Super 35mm, Full-frame, Medium format- which one should you get? Which one do you have? What the hell do those letters and numbers mean? Well, to go along with the body blog I just posted, this one is about the main component of a digital camera: the sensor. Every digital camera has a sensor, and each size depends on how big the end camera will end up. You can’t really have a Super 35mm sensor in a point-and-shoot body because it just won’t fit. A lot of other tech needs to fit into the body to go along with the sensor. Each different sensor has a pro and a con along with it’s size… the pro for a smaller sensor is size, weight and cost efficiency. Pro for the larger sensors is better viewing angles, thinner focus distance, and better low light performance.

Let’s get into it shall we? Let’s take good old 35mm.

This is the size of film you would normally use to take analog photos with. The millimeter size of the film is 35, Super 35 was used when 35mm film cameras were modified to use more of the negative than was used in 4:3 aspect ratio film to get a wide screen 16:9 aspect ratio. This transfers over to digital as well. APS-c or crop-sensors are very close in size to Super 35mm digital sensors, with only a small crop in between the two. The Super 35mm is the industry standard, but the “full-frame” is astonishingly wide. It takes where the holes or “perfs” would be and uses that area to calculate its sensor size, keeping a 16:9 aspect ratio.

Next is the crop sensor. Many brands of DSLR have a crop sensor, but none are exactly the same size. Canon’s crop sensor is around 60% smaller than the full frame and only a little smaller than Super 35mm Nikon’s is around 50% smaller than a FF sensor. A crop sensor can only capture a portion of what the full frame can, and what this means is that you’ll need wider lenses or to be further away from the scene you’re shooting to get the same framing. Wider lenses mean a deeper depth of field, and less compressed space. Smaller sensors also need more light to operate to get the same shot a FF sensor does. This point is exacerbated by smaller sensors such as the Micro Four Thirds (MFT) sensors. The MFT sensors further reduce their size so depth of field is greater, and more light is necessary to operate. You can get an adapter such as the Metabones Speed Booster to not only recapture the field of view of a full frame lens on a crop sensor body, but also increase the amount of light by a full stop! That’s fantastic, but the Metabones Speed Booster is $400-$650 depending on which body and lenses you’re adapting to.

Sensor size is a double edged sword though. That buttery smooth background you’re getting from a huge sensor and wide open lenses also means that focus is going to be a bitch and a half. The focus area is going to be razor thin and you’ll probably need a dedicated focus puller. A whole other crew member that will need expensive gear to use, and will probably blow focus at least once per scene.

There is no “right” answer to the question, “which camera is right for you?” It’s all subjective. Do you want to have a light rig, with one lens and a mic that you have to carry around a convention hall all day? Get a smaller sensor. Are you going to film more narrative, soft focus backgrounds, and have a ton of money? Get a big ass sensor and the lenses to go with it, or a small sensor and a Speed Booster. Like I said before, rent your gear before you buy it. It’s really one of the best ways to make sure you’re getting what you need to make your project. Once you know what you need, then you can make a purchase.