Content deleted Content added
m →Table of sensor formats and sizes: Fix capitalization |
→AnchorTable of sensor formats and sizes: Add link, fix model capitalization, and turn an external link into a citation |
||
| (9 intermediate revisions by 7 users not shown) | |||
Line 51:
:<math>\frac{P Q_e t}{\sqrt{P Q_e t}} = \sqrt{P Q_e t}</math>.
Apart from the quantum efficiency it depends on the incident photon flux and the exposure time, which is equivalent to the [[Exposure (photography)|exposure]] and the sensor area; since the exposure is the integration time multiplied with the image plane [[illuminance]], and illuminance is the [[luminous flux]] per unit area. Thus for equal exposures, the signal to noise ratios of two different size sensors of equal quantum efficiency and pixel count will (for a given final image size) be in proportion to the square root of the sensor area (or the linear scale factor of the sensor). If the exposure is constrained by the need to achieve some required [[depth of field]] (with the same shutter speed) then the exposures will be in inverse relation to the sensor area, producing the interesting result that if depth of field is a constraint, image shot noise is not dependent on sensor area. For identical f-number lenses the signal to noise ratio increases as square root of the pixel area, or linearly with pixel pitch. As typical f-numbers for lenses for cell phones and DSLR are in the same range {{f/|1.5|2}} it is interesting to compare performance of cameras with small and big sensors. A good 2018 cell phone camera with a typical pixel size of 1.1 μm (Samsung A8) would have about 3 times worse SNR due to shot noise than a 3.7 μm pixel interchangeable lens camera (Panasonic G85) and 5 times worse than a 6 μm full frame camera (Sony A7 III). Taking into consideration the dynamic range makes the difference even more prominent. As such the trend of increasing the number of "megapixels" in cell phone cameras during last 10 years was caused rather by marketing strategy to sell "more megapixels" than by attempts to improve image quality.
===Read noise===
Line 91:
In summary, as sensor size reduces, the accompanying lens designs will change, often quite radically, to take advantage of manufacturing techniques made available due to the reduced size. The functionality of such lenses can also take advantage of these, with extreme zoom ranges becoming possible. These lenses are often very large in relation to sensor size, but with a small sensor can be fitted into a compact package.
Small body means small lens and means small sensor, so to keep [[smartphone]]s slim and light, the smartphone manufacturers use a tiny sensor usually less than the 1/2.3" used in most [[bridge camera]]s. At one time only [[Nokia 808 PureView]] used a 1/1.2" sensor, almost
== Active area of the sensor ==
Line 127:
Some professional DSLRs, [[Sony SLT camera|SLTs]] and [[mirrorless camera]]s use ''[[full-frame DSLR|full-frame]]'' sensors, equivalent to the size of a frame of 35 mm film.
Most consumer-level DSLRs, SLTs and mirrorless cameras use relatively large sensors, either somewhat under the size of a frame of [[Advanced Photo System|APS]]-C film, with a [[crop factor]] of 1.5–1.6; or 30% smaller than that, with a crop factor of 2.0 (this is the [[Four Thirds System]], adopted by [[
{{As of|2013|11}}, there was only one mirrorless model equipped with a very small sensor, more typical of compact cameras: the [[Pentax Q#Pentax Q7|Pentax Q7]], with a 1/1.7" sensor (4.55 crop factor). See section [[
Many different terms are used in marketing to describe DSLR/SLT/mirrorless sensor formats, including the following:
* {{val|860|u=mm2}} area [[Full-frame digital SLR]] format, with sensor dimensions nearly equal to those of [[135 film|35 mm film]] (36×24 mm) from [[Pentax_K-1|Pentax]], [[Panasonic Corporation|Panasonic]], [[Leica Camera|Leica]], [[Nikon]], [[Canon (company)|Canon]], [[Sony]] and [[Sigma Corporation|Sigma]].
* {{val|370|u=mm2}} area [[APS-C]] standard format from [[Nikon]], [[Pentax]], [[Sony]], [[Fujifilm]], Sigma (crop factor 1.5) (
* {{val|330|u=mm2}} area [[APS-C]] smaller format from [[Canon Inc.|Canon]] (crop factor 1.6)
* {{val|225|u=mm2}} area [[Micro Four Thirds System]] format from Panasonic,
Obsolescent and out-of-production sensor sizes include:
Line 165:
Most sensors are made for camera phones, compact digital cameras, and bridge cameras. Most image sensors equipping compact cameras have an [[aspect ratio (image)|aspect ratio]] of 4:3. This matches the aspect ratio of the popular [[SVGA]], [[XGA]], and [[SXGA]] display resolutions at the time of the first digital cameras, allowing images to be displayed on usual [[computer monitor|monitor]]s without cropping.
{{As of|2010|12}} most compact digital cameras used small 1/2.3" sensors. Such cameras include Canon
As of 2018 high-end compact cameras using one inch sensors that have nearly four times the area of those equipping common compacts include Canon PowerShot G-series (G3 X to G9 X), Sony DSC
[[File:Sensor sizes area.svg|thumb|400px|right|For many years until Sep. 2011 a gap existed between compact digital and DSLR camera sensor sizes. The x axis is a discrete set of sensor format sizes used in digital cameras, not a linear measurement axis.]] Finally, Sony has the DSC-RX1 and DSC-RX1R cameras in their lineup, which have a full-frame sensor usually only used in professional DSLRs, SLTs and MILCs.
Line 173:
Due to the size constraints of powerful zoom objectives, most current [[bridge camera]]s have 1/2.3" sensors, as small as those used in common more compact cameras. As lens sizes are proportional to the image sensor size, smaller sensors enable large zoom amounts with moderate size lenses. In 2011 the high-end [[Fujifilm X-S1]] was equipped with a much larger 2/3" sensor. In 2013–2014, both Sony ([[Cyber-shot DSC-RX10]]) and Panasonic ([[Lumix DMC-FZ1000]]) produced bridge cameras with 1" sensors.
=== Medium-format digital sensors ===
Line 332:
|9.50||7.60||5.70||4:3||43.30||{{val|-4.32}}||4.55
|-
! scope="row" | 1/1.6" ([[F200EXR|Fujifilm
|10.07||8.08||6.01||4:3||48.56||{{val|-4.15}}||4.30
|-
Line 362:
|14.54||12.52||7.41||5:3||92.80||{{val|-3.22}}||2.97
|-
! scope="row" | 1" ([[Nikon CX format|Nikon CX]], [[Sony RX100]], [[RX10|Sony RX10]], [[
|15.86||13.20||8.80||3:2||116||{{val|-2.89}}||2.72
|-
Line 446:
|44.71||36.70||25.54||13:9||937.32||0.12||0.96
|-
! scope="row" | [[Red Digital Cinema Camera Company|RED]]
|46.31||40.96||21.60||17:9||884.74||0.03||0.93
|-
Line 452:
|54||45||30||3:2||1350||0.64||0.80
|-
! scope="row" | [[Pentax 645D]], Hasselblad X1D-50c, Hasselblad H6D-50c, CFV-50c,
{{cite web
|url=https://cdn.hasselblad.com/datasheets/x1d-II-50c/x1D-ii-50c-data-sheet.pdf
Line 460 ⟶ 459:
|date=2019-06-01
|access-date=2022-04-09}}
</ref>
{{cite web
|url=https://fujifilm-x.com/global/products/cameras/gfx-50s/specifications/
| |||