The size of a camera's sensor determines how much light it can gather to create an image, at least in part. While it makes sense that a bigger sensor can gain more information than a smaller one, producing better images, there are major perks to a smaller sensor.
The size of the sensor area can vary depending on the camera you are using, with each sensor size or format having a subtly different look that can affect the overall visual tone of your project. While there are loads of different cameras with loads of different formats and sensor sizes, there are five that are most commonly used in film production today and have been standardized by film history.
In Depth Cine breaks down the five most popular formats—Super 16, Super 35, Full Frame, 65mm, and IMAX—and the effects of each sensor size. Understanding which format will help you decide which camera and sensor sizes will best serve your production with ease.
Why Sensor Size Matters
Let's start with sensor size. The smaller the sensor is, the tighter the image it will record. If we take a full-frame lens as an example, with an image circle of roughly 43mm, we will see that a full-frame sensor at 36mm by 24mm will be able to capture the entire image that the lens produces. However, if we utilize a smaller sensor, such as a Super 35, Micro Four Thirds, or Super 16 sensor, they will capture a small area of the image circle, in turn giving you a different field of view.
This affects the feeling of depth and perspective in your image, at least indirectly, as you will have to reposition your camera to achieve similar framing. Due to this, the sensor will affect the range of focal lengths that need to be used on the camera, as a 50mm lens will behave differently on different-sized sensors. Take a look at this guide from Abelcine to learn more!
The five most popular sensor sizes in filmCredit: In Depth Cine
Field of View and Depth of Field
Let's elaborate further. To compensate for the difference between the field of view, smaller formats like Super 16 need a wider angle lens to get an image that sees the same amount of information while a larger format requires a longer lens for that frame.
This is why the depth of field is also (indirectly) affected across formats because of the difference in the field of view. On a larger sensor, creatives will need to utilize longer focal lengths and reposition their cameras, which in turn may create a shallow depth of field, meaning that more of the background will be out of focus and the subject will be further separated from the background. Even though there are many attributes to a "cinematic" image, this effect does allow a more cinematic look as it creates a three-dimensional feel to the image.
The downside of this, however, is that the job of the 1st AC will become more difficult as it is harder to consistently keep the focus sharp. Smaller formats are often more forgiving due to them indirectly creating a deeper depth of field, which keeps more of the image in focus. Back in the days of celluloid, DPs who cut their teeth as ACs preferred working in Super 16, as it was easier to nail your focus.
Super 35 ARRI Mini vs 65mm ARRI 65Credit: manuelluebbers
Grain and Noise
Speaking of celluloid, the grain and resolution of an image are also affected by the size of the format (at least on film). The smaller the film stock is, the more noticeable the grain or noise texture will usually be. Just go and compare Super 16 to IMAX. In turn, the larger the film negative is, the greater the resolution will be, creating a clear and crisp image.
However, when it comes to digital sensors, smaller doesn't always mean more grain (or noise). While larger sensors do have better noise control because of more surface area, cameras are getting so good that it's not the same as back in the film days.
Of course, with digital, you can always add grain in post to create the desired level of texture if you are wanting a specific image. This means that even on full-frame digital cinema cameras, you can mimic the texture and feel of Super 16!
Show Me the Money!
Lastly is the price difference. Obviously, the larger you go, the more expensive it is to shoot on, with smaller formats being extremely budget-friendly.
Let's look at celluloid film as an example. Super 35 film stock is larger, but is also more expensive, not only to purchase but also to process and scan. Super 16, on the other hand, can be a great alternative and is still used to shoot indie features on a budget. Here's a great breakdown from Noam Kroll on his experiences with budgeting for Super 16.
When we look at the digital world, the same price patterns also kind of apply. Larger sensors like full-frame (called large format in the cine world) require more processing power than MFT or Super 16 sensors. This demands more complex electronics and thus raises the price. But as technology gets better, these prices will fluctuate a lot. Just look at the Fujifilm GFX 100s with its larger than full-frame sensor! Getting that kind of tech before Fuji would have been a rental only (if we excluded Hasselblad, since its video options weren't great).
DZO Pictor Zooms for Super 35Credit: DZOfilm
This is also where lenses become a big factor. While you can use full-frame glass to shoot on any sensor smaller than the image circle, those lenses aren't always the cheapest. You're also leaving a lot of image cirlce on the table if you shoot on a smaller sensor. This is why some lenses are built for specific sensor or film format. Most notably, Super 35 and Super 16. Lenses for these formats produce an image circle that perfectly nestles the frame inside it, without any extra.
These lense are most often cheaper to produce, are lighter, and may have better image quality than their bigger brothers. This won't even affect your focal length, since a 50mm is a 50mm, as the old saying goes.
Super 16 film is the smallest regularly used format in film production. The film’s smaller size of 12.5x7.4mm makes this a cheap option because less physical film stock is required. Due to its accessibility, Super 16 was often used in the past to capture lower-budget productions.
Since digital cameras have overtaken film, the Super 16 is mainly chosen for its optical characteristics rather than its price point. Its grittier image quality produces beautiful film grain and is often used today to evoke a rougher sense of nostalgia with the deeper depth of field it indirectly produces, which keeps more of the image in focus.
Some digital cameras like the original Blackmagic Pocket Cinema Camera have a Super 16 sensor, with the newer iterations carrying MFT and Super 35-sized sensors. Cameras like the ARRI Alexa Mini LF, which have bigger sensors, can record in specialized recording modes that sample a Super 16 size area of the sensor.
'Moonrise Kingdom' shot on Super 16Credit: Focus Features
Super 35 has become the most commonly used format today and is based on the 35mm motion picture film size that covers an approximate area of 24.9x18.6mm. While the film stock is the same size as regular photography film, the film is exposed with the reel running vertically instead of horizontally and can capture different amounts of that horizontal space depending on the budget, aspect ratio, and lenses used.
The frame can also be cropped to use less film stock or to extract a widescreen image when used with a spherical lens. Shooting with an anamorphic lens will use the entire area of the negative, optically squeezing the image. This will have to be de-squeezed in a later stage to get to a 2.39:1 aspect ratio.
Many digital cinema camera sensors are modeled on this sensor size, with some minor size variations, like the ARRI Alexa Mini, RED Dragon S35, and the Sony F65. The format is extremely popular for its film grain and simplistic yet gorgeous depth of field, which is probably why this format has the widest selection of cinema lenses available.
'Licorice Pizza'Credit: United Artists Releasing
This size, also known as large format, as we mentioned before, is modeled on still photography film or a 35mm image sensor format, such as the Canon 5D. Full-frame is also around the same size as 8-perf Vista Vision film, which runs the film horizontally like a regular photography film camera. Although digital sensors differ a bit depending on the desired aspect ratio, it is usually about 36x24mm.
Some cameras with this sensor size include the Alexa LF, Sony VENICE, and the Canon C700 FF. This large format is placed in the middle ground between the Super 35 and the 65mm, creating a shallower field depth with a little bit of film grain or reduced noise.
'The Possession of Hannah Grace'Credit: Sony Pictures Releasing
Originally, this format was based on 65mm gauge film, which was 3.5 times as large as the standard 35mm, and measured 52.6x23mm using five vertical perforations with a widescreen aspect ratio of 2.2:1.
The Alexa 65 has a digital sensor that matches 65mm film and is a viable digital version of this format, even though it's rental only at this point in time. Using a 65mm format camera will produce a wider field of view than the 35mm format while maintaining a shallower depth of field and a more compressed rendering of space. This means you can see wider without going wider on your lens!
'The Hateful Eight'Credit: The Weinstein Company
This is the largest motion picture format you can shoot and doesn't really have a digital equivalent. Often reserved for big-budget films or documentaries that look to enhance the movie-watching experience, IMAX film requires specialized cameras to shoot it and someone who knows how to work with the film and cameras.
With an enormous 15 perforations per frame, an IMAX frame covers a 70.4x52.6mm image area. Due to its huge negative size and the specialized cameras required to shoot it, this format is expensive and is out of the budget range for most productions.
'Nope'Credit: Universal Pictures
Food for Thought
Does sensor size matter in the end? Yes, if you are looking to achieve a specific visual and cinematic tone.
But is one sensor size better than another? No! It's just the effects each one provides are different. The format that will work best for you is entirely dependent on what the project needs. Always choose what is going to serve your story rather than achieve a specific visual language that doesn’t work with or for the story.
Knowing what will work best for the project is always great filmmaking knowledge, and can take you far in the industry. Let us know your thoughts in the comments!
Source: In Depth Cine