- Introduction
- History
- The system sizes- who and what size
- camera phones
- Nikon M1
- Micro 4/3
- APS-C
- Canon EF-S – EF-M
- Fuji X, Nikon, Pentax,Sony
- 35mm
- Medium Format
- Large Format
- Conclusions
- No system size is inherently ‘best’
- No One system is likely to ‘rule them all‘ any time soon
Introduction
Different cameras all have different sensor sizes. This page lists and the sizes of different systems and provides some measure of comparison of size, as well as listing the current (March 2018) megapixel counts of each system. This page is not about merits of size nor megapixel, just a pool of data to reference in any discussion.
While smart phones are not a ‘system’, they are also compared, as they are certainly significant.
History
The days of film.
Cameras all produce images on a sensor. At one time the sensor was film, so the camera required the appropriate film size. The first camera makers had to make both film and the cameras. Well known brands include Fuji, Agfa and Kodak. Manufacturers producing only cameras (eg. Canon, Nikon) had to rely on independently produced film being readily available.
To make a new system size, there need to be a new film, new cameras and new lenses. Despite the need for such an ecosystem, there have been a multitude of film sizes. Even under all these constraints, a huge plethora of formats have existed.
The Size Trend – > Smaller.
At one time the main film sizes were ‘large format‘, ‘medium format’ and 35mm. This smaller 35mm is now often referred to somewhat confusingly as ‘full frame’. Large format is now only in restricted usage, with usage by the press dropping as long ago as the 1950s. At the dawn of the digital era, professional photographers used medium format, unless they were photographing for lower resolution newsprint or long range zoom sports photographs, but with the increase of resolution of 35mm photographs with digital print, medium format is also overall becoming more specialised than mainstream, and newer far smaller images such as even those taken with smart phones are in wider and wider usage.
The System Sizes
Phones: 4.07×3.05mm – 12.4mm2
The figures quoted are for ‘normal’ lens of the iPhoneX. The iPhoneX actually has 3 cameras, and these measurement are for the rear telephoto lens, firstly because it is a sound choice and secondly because I could find the specifications.
The iPhone X actually has 3 cameras. The two rear cameras are the ones designed to produce the highest quality photos. It is difficult to find actual specifications, but the 56mm equivalent lens indicates and actual focal length of 6mm. This may not be exact, but yields a ratio of 9.3333 compared to a 35mm camera. Update: I have since another report the length is actually 6.6mm yielding a ration of 8.4848, so I have based calculations on this figure, which suggest an approximately 10% larger sensor than would be the case with 6mm focal length. So it is possible the calculations here are for a sensor 10% larger than the actual, and if I discover this is the page I will adjust, but assume the larger value until that time.
The 35mm sensor has a diagonal of 43.2mm, which divided by 8.4848 suggests an sensor with an 5.09mm diagonal. The ratio of the width to height is 4:3 ..which by Pythagoras theorem gives a diagonal of 5. So width is 5.09 x 4/5 and height is 5.09 x 3/5.
The figures may not actually be precise. Is the focal length actually 6? or even 5.9mm, or 5.95, or 6.05…. or is the 6.6 also slightly out? There is also a suggestion the focal length of the telephoto lens is 52mm and the image is cropped to 56mm…. but that would mean the effective area matches the calculations anyway. I am not certain of the exact precision, but given the iPhone is representing phone cameras in general, the figures are sufficiently representative of a high quality smart phone camera.
Nikon 1: 13.2×8.8mm – 116.2mm2
- Potential pixels at camera phone scale: 108 megapixels
- Actual maximum: 21 Megapixels
The smallest of the genuine ‘systems’ with interchangeable lenses, the Nikon 1 system, is eleven times (9x) larger than the iPhone X sensor. This would suggest 12 x 9 = 108 megapixels would be possible at the density of the iPhone. However, the highest resolution, the J5, has 20.8 megapixels.
First introduced in 2011, there have been no new cameras for this system since 2015 leading, to fears the system is to be abandoned. Despite this, the system has genuine fans.
Micro Four Thirds(m4/3): 17.3mm x13mm – 225mm2
- Potential pixels at camera phone scale: 216 Megapixels
- Potential pixels at Nikon 1 scale: 40 Megapixels
- Actual maximum: 21 Megapixels
Micro four thirds is the only system with the same mount shared between manufacturers (Panasonic and Olympus, plus some smaller participants).
Just over twice the area of the Nikon 1 system, Micro 4/3 cameras currently have a similar maximum resolution of 20 megapixels, rather than the 40 megapixels that would result from the same density as the Nikon 1 or, the over 216 megapixels that would scale up from a smartphone with sensor around 18 times smaller.
Canon M System (APS-C): 22.2mm x 14.8mm – 329mm2
(+Canon APS-C subsystem of Canon 35mm is the same size sensor)
- Potential pixels at camera phone scale: 318 Megapixels
- Potential pixels at Nikon 1 scale: 57 Megapixels
- Potential pixels at M43 scale: 29 Megapixels
- Actual maximum: 24 Megapixels
The Canon APS-C DSLR subsystem uses the same sensor size as the mirrorless Canon M-System, but the DSLR system is a subsystem of a 35mm system, both of which use a slightly smaller sensor than other APS-C systems.
Just under 1.5 times the size of the smaller m43 system, the increase in pixels is small (as is the real size change) but there is more colour depth available.
The M system appears to use the same sensors as the Canon APS-C DSLR cameras, but the M system is a mirrorless system based around what appears to be an APS-C mount, while Canon DSLR APS-C cameras use a mount designed for ‘full frame’ 35mm sensors, and crops the image coming in from the lens.
EF-M and full frame: It appears that EF-M is a APS-C size system, but this may not be true. The Sony E-Mount also launched with only APS-C sensors, but it was later revealed they were a crop of what the mount, and lenses could deliver. The same may be true with EF-M and this may actually be a full frame capable mount.
Fuji X mount APS-C System: 23.6mm x 15.6mm – 368mm2
(Nikon, Sony, and Pentax APS-C subsystems of respective 35mm are the same size sensor, with a variation of up to 0.1mm in width)
- Potential pixels at camera phone scale: 318 Megapixels
- Potential pixels at Nikon 1 scale: 57 Megapixels
- Potential pixels at M43 scale: 29 Megapixels
- Actual maximum: 24 Megapixels
The mirrorless Fuji X mount system is the an actual system designed on the same size as APS-C DSLR subsystems from Sony, Nikon and Pentax. While this mount is smaller than the main systems from Canon and Nikon, Fuji, like Pentax, also has a system with a larger mount than Canon and Nikon.
35mm (135 format) Full Frame: 36mm X 23.9 – 24.3mm – 860 – 864mm2
Nikon, Canon, Sony and Pentax all have digital mounts for this size. 35mm, the smaller size of the two most common system sizes in the film area at the time digital cameras emerged, is a system size that originated in the 1920s.
- Potential pixels at camera phone scale: 850+ Megapixels
- Potential pixels at Nikon 1 scale: 148 Megapixels
- Potential pixels at M43 scale: 76 Megapixels
- Potential pixels at APS-C scale: 62 Megapixels
- Actual maximum: 50 Megapixels
The M system appears to use the same sensors as the Canon APS-C DSLR cameras, but the M system is a mirrorless system based around an APS-C mount, while Canon DSLR APS-C cameras use a mount designed for ‘full frame’ 35mm sensors, and crops the image coming in from the lens.
Hasselblad X1D, Cropped Medium Format: 43.8 x 32.9 mm – 1,441mm2
Just 1.6 times 35mm full frame, is small for medium format, but still offers an advantage in colour depth and the quality of some of the lenses available. Similar to the step up from m43 to APC
- Multiply the figures for 35mm by 1.6
- potential pixels at 35mm scale 80 Megapixels
- actual maximum pixels 50
Medium format and similar lens/mount sizes are common to Hasselblad, Fuji, Pentax, Mimolta and Phase One. However all of these suppliers can use the other medium format size sensors listed below and either do that already or a likely to in future.
Hasselblad H1D: Cropped Medium Format 49.0mm X 36.7 – 1,798.3mm2
Two time (2x) the 35mm full frame, this sensor size does make for sense for the future of medium format.
Medium Format 645 (Phase One P65): 53.9mm x 40.4mm – 2,177.6mm2
2.5 times the size of full frame 35mm, this is the first medium format sensor size that is not necessarily a crop. The all medium formats are capable of this size, but the only current product using this size is the Phase One P65.
Large Format: 127mm X 102mm – x 12,954mm2 (and larger)
Fifteen time (15x) the size of 35mm full frame, and over a thousand times (1,000x) the size of a typical phone sensor, large format was the main format of photography for most of the history of photography. But the format of artists such as Ansell Adams, is now a very specialist format. With a trends like a revival of film perhaps large format may play an important role, but there is also large format digital, predominantly through the use of digital camera backs.
Conclusions.
No System size is inherently ‘best’.
The first photographs needed no enlargement, as the size of film was appropriate for viewing. Then smaller and smaller sizes were created on the basis that the photo could be enlarged, and as film grain size decreased, greater enlargement was feasible.
With film, the same grain size, or ‘pixel density’ is feasible regardless of film size. This means that with film, a phone sized film would have , 175 times less pixels than a 645 medium format size film.
Despite quality advantage of larger film, smaller film means smaller lenses and more portability and many images were only needed for newsprint.
Different sizes systems were most popular for different uses.
The same compromise between sensor size and image quality exists with digital, but digital has the new factor that ‘finer grain’, or increased pixel density, is easier to achieve with a smaller sensor. This results in phone size sensor having around 1/8th of the pixels of 645 medium format sensors, a significant improvement of the 1/175th they would have with the same pixel size.
Although all pixels are not the same, with digital it is clear that the compromise with smaller sensor size is less than in the days of film. With less disadvantage to small sensors, there is an even wider range of possible sizes and it is even harder to choose the best compromise.
Every system is a compromise or we would all simply choose the largest sensor and move to large format. The reality is that even medium format is too inconvenient for most photographers and the even smaller, ‘small format’ 35mm is more popular despite naturally having lower quality potential. In fact camera phones are the most popular of all despite the lowest quality potential of all.
One system is unlikely to rule them all any time soon.
There is still a trend for several incompatible systems to have a common sensor size, just as in the days where these systems were the same size in order to use the same film. In practice, sensors are now produced by companies independent of the camera makers, and just as in the days of film, several different brand cameras may in practice use the same sensor.
Only the m43 (micro four thirds) system is promoted as an open system, although several brands may in practice use the same ‘proprietary’ mount. For example, for the Canon EF mount, there are not only third party lenses, but even third party cameras.
Highly profitable Chinese drone maker DJI is now a majority owner in Hasselblad, who have since that investment introduced new medium format systems, as has Fuji, others such as Pentax and Leica still produce new models, so clearly the scope still spans from medium format to camera phones.
Systems will come and go, but a wide range seems ensured for a long time.
