Every camera has a sensor, and one of the biggest differentiators between cameras is the physical size of the sensor. Which size is best? Are there any sizes you need to avoid?
If you’re a beginner to cinematography you’ll be hard-pressed to wrap your head around all the marketing BS and technical jargon.
Here’s a quick video of the simplest explanation I can think of:
The sensor size
A sensor size is always written as the:
Length of the sensor (in mm) x Height of the sensor (in mm).
The reason it’s in millimeters is because the sensors are small, and the number in millimeters is easier to remember. Nothing fancy.
Is there a standard sensor size?
There isn’t one. The only standard from film that has survived the digital revolution is the Full Frame or 135 format (from photography). The size of this sensor is:
36mm x 24mm
35mm film for photography was (and is) the same size.
This is why I use this size to calculate my crop factors and the 35mm equivalent.
What about cinema?
Cinema has its own standards, but most of them have changed numerous times over the years, and are hard to track down and understand.
The only surviving ‘standard’ (in quotes because it’s still open to interpretation) is:
Super 35. The length is 24.89mm, in 3-perf.
What about the height?
It can vary depending on the aspect ratio. Cinema (DCP) has two ‘popular’ aspect ratios:
- Flat: 1.85:1
- Scope: 2.39:1
Depending on this the height can change.
However, modern cinema cameras don’t strictly stick to the 24.89mm sensor size. E.g., the Arri Alexa 35 is a Super 35mm cinema camera, and it has a sensor size of 27.99 mm x 19.22 mm.
Here’s a table of some cameras and their horizontal sensor sizes:
| Camera | Horizontal sensor size in mm |
| IMAX film | 69.6 |
| Arri Alexa 65 | 54.12 |
| 65mm film | 52.6 |
| Red V-Raptor XL | 40.96 |
| Arri Alexa LF | 36.7 |
| Full Frame Mirrorless cameras | 36 |
| Sony Venice 2 | 36 |
| Super 35 Film | 24.89 |
| Arri Alexa Mini | 28.25 |
| Canon APS-C (Typical) | 22.2 |
| 35mm Academy Film | 21.95 |
| MFT sensors | 17.3 |
| Super 16 Film | 12.52 |
| Super 8 Film | 5.79 |
I’m overwhelmed! Which is the best?
I know, if you’re a newcomer you’ll have no clue.
Here’s my simple suggestion. You can differentiate sensor sizes using this matrix (this is overly simplified, so please realize it’s only for new filmmakers who aren’t accustomed to the terminology):
| At the same resolution | Better the | Worse the |
| Larger the sensor | Light collecting ability (low light ability), shallow depth of field | Price, lens size and weight |
| Smaller the sensor | Depth of field, smaller lenses | low light performance |
In theory you should be able to recreate the exact same look with large or small sensors given perfect conditions. But it’s never the case. In the real world, you can never match two sensors 100%, and that means:
Each sensor-size and lens combination has its own look. It’s not ‘better’ or ‘worse’, but different.
Aesthetically different.
In short, pick a sensor like you would pick a paint brush…or a toothbrush.
Or ice cream.
Why do people praise large sensor cameras?
Let’s say you go to the market to buy mangoes. There are two boxes, one with small mangoes and next to it another box with bigger mangoes.
Do bigger mangoes always taste better than the smaller mangoes?
You and I know that’s not the case. Small mangoes can taste great too.
But what if it said on the box with the bigger mangoes: Bigger Mangoes Taste Better!
To a person who doesn’t know any better, they’d be fooled. That’s how a newcomer to filmmaking feels. They don’t have any experience to fall back on.
In our mango analogy, you can change parameters make it even more confusing – change the quality of the box, mangoes are of a different color, one bunch of mangoes have a hologram sticker, the bigger size is from an exotic country, and so on.
When many parameters are changed at the same time, it makes it more consuming. Newbie filmmakers? They’re ripe for the taking!
Many camera manufacturers use FUD to confuse their product line.
They might cleverly neglect to add features found in their more expensive camera to the smaller-sensor camera. So, the sensor itself isn’t worse, but a combination of features together.
You have to ask yourself: Why don’t they keep the features the same? If the sensor-size was so obviously important, surely they don’t have to omit their cutting edge technology on any of their cameras. They want you to associate image quality with sensor size, when it isn’t. They hope you won’t notice.
That’s because many of these camera manufacturers are not selling to serious filmmakers, but to the lowest common denominator. I’m not naming any names, but many popular brands twist the truth this way.
Therefore, when you buy big-sensor cameras, you’re not only paying extra for the bigger sensor, but probably also for additional features in the camera.
Bottom line: Don’t equate image quality to sensor size unless every other parameter is similar.
Which sensor should I prefer?
Here’s the best answer to this question: Don’t bother about the sensor!
See what others have done with the cameras you’re interested in. If the work is great, the camera can facilitate that.
A camera with a larger sensor is not going to make you a better cinematographer. It’s not going to make your film any better either.
Wearing the best running sneakers in the world isn’t going to win you an Olympic medal, nor is it going to make you the fastest human. The same applies to cameras:
Point your expensive camera at crap if you want to, but it won’t make crap look expensive.
An expensive camera will surely empty your wallet, but won’t guarantee production values. Then isn’t it better to spend your money on what will guarantee production values? Things like better actors or models, better sets and wardrobe, traveling, extra hands, and so on?
Watch this video to know more about that:
I hope this simple explanation of sensor sizes has helped you understand it on a gut-level. That was all I intended to accomplish.
If you feel it has helped, please let me know in the comments below!
