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| [[File:Sensor sizes overlaid inside - updated.svg|thumb|upright=1.8|Comparative dimensions of sensor sizes]]
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| In [[digital photography]], the '''image sensor format''' is the shape and size of the [[image sensor]].
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| The image sensor format of a [[digital camera]] determines the [[angle of view]] of a particular lens when used with a particular camera. In particular, [[image sensor]]s in [[digital SLR]] cameras tend to be smaller than the 24 mm × 36 mm image area of [[Full-frame digital SLR|full-frame]] [[35mm|35 mm]] cameras, and therefore lead to a narrower angle of view.
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| Lenses produced for [[35 mm film]] [[Single-lens reflex camera|cameras]] may mount well on the digital bodies, but the larger [[image circle]] of the 35 mm system lens allows unwanted light into the camera body, and the smaller size of the image sensor compared to 35 mm film format results in cropping of the image. This latter effect is known as field of view crop. The format size ratio (relative to the 35 mm film format) is known as the field of view crop factor, [[crop factor]], lens factor, focal length conversion factor, focal length multiplier or lens multiplier.
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| == Sensor size and depth of field ==
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| Three possible depth of field comparisons between formats are discussed, applying the formulae derived in the article on [[Depth_of_field#DOF_vs._format_size_2|depth of field]]. The depths of field of the three cameras may be the same, or different in either order, depending on what is held constant in the comparison.
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| Considering a picture with the same subject distance and angle of view for two different formats:
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| :<math> \frac {\mathrm{DOF}_2} {\mathrm{DOF}_1} \approx \frac {d_1} {d_2}</math> | |
| so the DOFs are in inverse proportion to the absolute [[Aperture#In_photography|aperture diameters]] <math>d_1</math> and <math>d_2</math>.
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| Using the same absolute aperture diameter for both formats with the “same picture” criterion (equal angle of view, magnified to same final size) yields the same depth of field. It is equivalent to adjusting the [[f-number]] inversely in proportion to [[crop factor]] – a smaller f-number for smaller sensors. (This also means that, when holding the shutter speed fixed, the exposure is changed by the adjustment of the f-number required to equalise depth of field. But the aperture area is held constant, so sensors of all sizes receive the same total amount of light energy from the subject. The smaller sensor is then operating at a lower [[film speed|ISO setting]], by the square of the crop factor.)
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| And, we might compare the depth of field of sensors receiving the same [[Luminous_exposure#Photometric_and_radiometric_exposure|photometric exposure]] – the f-number is fixed instead of the aperture diameter – the sensors are operating at the same ISO setting in that case, but the smaller sensor is receiving less total light, by the area ratio. The ratio of depths of field is then
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| :<math> \frac {\mathrm{DOF}_2} {\mathrm{DOF}_1} \approx \frac {l_1} {l_2}</math>
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| where <math> l_1</math> and <math>l_2</math> are the characteristic dimensions of the format, and thus <math>l_1/l_2</math> is the relative crop factor between the sensors. It is this result that gives rise to the common opinion that small sensors yield greater depth of field than large ones.
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| An alternative is to consider the depth of field given by the same lens in conjunction with different sized sensors (changing the angle of view). The change in depth of field is brought about by the requirement for a different degree of enlargement to achieve the same final image size. In this case the ratio of depths of field becomes
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| :<math> \frac {\mathrm{DOF}_2} {\mathrm{DOF}_1} \approx \frac {l_2} {l_1} </math>.
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| == Sensor size, noise and dynamic range ==
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| Discounting [[Fixed-pattern noise|pixel response non-uniformity]] (PRNU), which is not intrinsically sensor-size dependent, the noises in an image sensor are [[shot noise]], [[read noise]], and [[dark noise]]. The overall [[Signal-to-noise ratio|signal to noise ratio]] of a sensor (SNR), observed at the scale of a single pixel, is
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|
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| :<math> \mathrm{SNR} = \frac{P Q_e t}{\sqrt{P Q_e t + D t + N_r^2}} </math>
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| where <math>P</math> is the incident photon flux (photons per second in the area of a pixel), <math>Q_e</math> is the [[quantum efficiency]], <math>t</math> is the exposure time, <math>D</math> is the pixel dark current in electrons per second and <math>N_r</math> is the pixel read noise in electrons.<ref name="noise">{{cite web|last=Fellers|first=Thomas J.|title=CCD Noise Sources and Signal-to-Noise Ratio|url=http://micro.magnet.fsu.edu/primer/digitalimaging/concepts/ccdsnr.html|publisher=Hamamatsu Corporation|accessdate=20 November 2013|coauthors=Davidson, Michael W.}}</ref>
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| Each of these noises has a different dependency on sensor size.
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| ===Exposure and photon flux===
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| Image sensor noise can be compared across formats for a given fixed photon flux per pixel area (the ''P'' in the formulas); this analysis is useful for a fixed number of pixels with pixel area proportional to sensor area, and fixed absolute aperture diameter for a fixed imaging situation in terms of depth of field, diffraction limit at the subject, etc. Or it can be compared for a fixed focal-plane illuminance, corresponding to a fixed [[f-number]], in which case ''P'' is proportional to pixel area, independent of sensor area. The formulas above and below can be evaluated for either case.
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| ===Shot noise===
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| In the above equation, the shot noise SNR is given by
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| :<math>\frac{P Q_e t}{\sqrt{P Q_e t}} = \sqrt{P Q_e t}</math>.
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| 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.
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| ===Read noise===
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| The read noise is the total of all the electronic noises in the conversion chain for the pixels in the sensor array. To compare it with photon noise, it must be referred back to its equivalent in photoelectrons, which requires the division of the noise measured in volts by the conversion gain of the pixel. This is given, for an [[active pixel sensor]], by the voltage at the input (gate) of the read transistor divided by the charge which generates that voltage, <math>CG = V_{rt}/Q_{rt}</math>. This is the inverse of the capacitance of the read transistor gate (and the attached floating diffusion) since capacitance <math>C = Q/V</math>.<ref>{{cite web|last=Aptina Imaging Corporation|title=Leveraging Dynamic Response Pixel Technology to Optimize Inter-scene Dynamic Range|url=http://www.aptina.com/products/technology/DR-Pix_WhitePaper.pdf|publisher=Aptina Imaging Corporation|accessdate=17 December 2011}}</ref> Thus <math>CG = 1/C_{rt}</math>.
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| In general for a planar structure such as a pixel, capacitance is proportional to area, therefore the read noise scales down with sensor area, as long as pixel area scales with sensor area, and that scaling is performed by uniformly scaling the pixel.
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| Considering the signal to noise ratio due to read noise at a given exposure, the signal will scale as the sensor area along with the read noise and therefore read noise SNR will be unaffected by sensor area. In a depth of field constrained situation, the exposure of the larger sensor will be reduced in proportion to the sensor area, and therefore the read noise SNR will reduce likewise.
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| ===Dark noise===
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| The dark current contributes two kinds of noise: dark offset, which is only partly correlated between pixels, and the shot noise associated with dark offset, which is uncorrelated between pixels. Only the shot-noise component ''Dt'' is included in the formula above, since the uncorrelated part of the dark offset is hard to predict, and the correlated or mean part is relatively easy to subtract off. The mean dark current contains contributions proportional both to the area and the linear dimension of the photodiode, with the relative proportions and scale factors depending on the design of the photodiode.<ref>{{cite journal|last=Loukianova|first=Natalia V.|coauthors=Folkerts, Hein Otto; Maas, Joris P. V.; Verbugt, Joris P. V.; Daniël W. E. Mierop, Adri J.; Hoekstra, Willem; Roks, Edwin and Theuwissen, Albert J. P.|title=Leakage Current Modeling of Test Structures for Characterization of Dark Current in CMOS Image Sensors|journal=IEEE Transactions on Electron Devices|date=January 2003|volume=50|issue=1|pages=77–83|doi=10.1109/TED.2002.807249|url=http://www.harvestimaging.com/pubdocs/073_2003_jan_TED_leakage_current.pdf|accessdate=17 December 2011}}</ref> Thus in general the dark noise of a sensor may be expected to rise as the size of the sensor increases. However, in most sensors the mean pixel dark current at normal temperatures is small, lower than 50 e- per second,<ref>{{cite web|title=Dark Count|url=http://www.ccd.com/ccd109.html|publisher=Apogee Imaging Systems|accessdate=17 December 2011}}</ref> thus for typical photographic exposure times dark current and its associated noises may be discounted. At very long exposure times, however, it may be a limiting factor. And even at short or medium exposure times, a few outliers in the dark-current distribution may show up as "hot pixels".
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| ===Dynamic range===
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| Dynamic range is the ratio of the largest and smallest recordable signal, the smallest being typically defined by the 'noise floor'. In the image sensor literature, the noise floor is taken as the readout noise, so <math> DR = Q_{max} / \sigma_{readout}</math><ref>{{cite journal|last=Kavusi|first=Sam|coauthors=El Gamal, Abbas|title=Quantitative Study of High Dynamic Range Image Sensor Architectures|journal=Proc. of SPIE-IS&T Electronic Imaging|year=2004|volume=5301|pages=264–275|url=http://www-isl.stanford.edu/groups/elgamal/abbas_publications/C099.pdf|accessdate=17 December 2011}}</ref> (note, the read noise <math>\sigma_{readout}</math> is the same quantity as <math>N_r</math> referred to in<ref name="noise" />)
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| The measurement here is made at the level of a pixel (which strictly means that the DR of sensors with different pixel counts is measured over a different spatial bandwidth, and cannot be compared without normalisation). If we assume sensors with the same pixel count but different sizes, then the pixel area will be in proportion to the sensor area. If the maximum exposure (amount of light per unit area) is the same then both the maximum signal and the read noise reduce in proportion to the pixel (and therefore the sensor) area, so the DR does not change. If the comparison is made according to DOF limited conditions, so that the exposure of the larger sensor is reduced in proportion to the area of the sensor (and pixel, for sensors with equal pixel count) then <math>Q_{max}</math> is constant, and the read noise (<math>\sigma_{readout}</math>) falls with the sensor area, leading to a higher dynamic range for the smaller sensor.
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| Summarising the above discussion, considering separately the parts of the image signal to noise ratio due to photon shot noise and read noise and their relation to the linear sensor size ratio or 'crop factor' (remembering that conventionally crop factor increases as the sensor gets smaller) then:
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| {| class="wikitable"
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| |-
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| ! !! Shot noise SNR !! Read noise SNR !! Dynamic range
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| | Fixed exposure || Inversely proportional to crop factor || No change || No change
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| | DOF constrained || No change || Proportional to square of crop factor || Proportional to square of crop factor
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| |}
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| It should be noted that this discussion isolates the effects of sensor scale on SNR and DR, in reality there are many other factors which affect both these quantities.
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| == Sensor size and diffraction ==
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| The resolution of all optical systems is limited by [[diffraction]]. One way of considering the effect that diffraction has on cameras using different sized sensors is to consider the [[Optical transfer function|modulation transfer function]] (MTF) due to diffraction, which will contribute a factor to the overall system MTF along with the other factors, typically the MTFs of the lens, anti-aliasing filter and sensor sampling window.<ref name=LLResolution>{{cite web|last=Osuna, Rubén & García, Efraín|title=Do Sensors "Outresolve" Lenses?|url=http://www.luminous-landscape.com/tutorials/resolution.shtml|publisher=The Luminous Landscape|accessdate=21 December 2011}}</ref> The spatial cut-off frequency due to diffraction through a lens aperture is
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| :<math>\xi_\mathrm{cutoff}=\frac{1}{\lambda N}</math>
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| where λ is the wavelength of the light passing through the system and N is the [[f-number]] of the lens. If that aperture is circular, as are (approximately) most photographic apertures, then the MTF is given by
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| :<math>\mathrm{MTF}(\xi / \xi_\mathrm{cutoff})=\frac{2}{\pi} \left \{ \cos^{-1}(\xi / \xi_\mathrm{cutoff})-(\xi / \xi_\mathrm{cutoff})\left [ 1-( \xi / \xi_\mathrm{cutoff})^2 \right ]^{1/2} \right \}</math>
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| for <math> \xi < \xi_\mathrm{cutoff} </math> and <math> 0 </math> for <math> \xi \ge \xi_\mathrm{cutoff} </math><ref name=DiffractionMTF>{{cite book|last=Boreman|first=Glenn D.|title=Modulation Transfer Function in Optical and Electro-Optical Systems|year=2001|publisher=SPIE Press|isbn=978-0-8194-4143-0|pages=120|url=http://spie.org/x34304.xml}}</ref>
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| The diffraction based factor of the system MTF will therefore scale according to <math>\xi_\mathrm{cutoff}</math> and in turn according to <math> 1/N </math> (for the same light wavelength).
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| In considering the effect of sensor size, and its effect on the final image, the different magnification required to obtain the same size image for viewing must be accounted for, resulting in an additional scale factor of <math>1/{C}</math> where <math>{C}</math> is the relative crop factor, making the overall scale factor <math>1 / (N C)</math>. Considering the three cases above:
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| For the 'same picture' conditions, same angle of view, subject distance and depth of field, then the F-numbers are in the ratio <math>1/C</math>, so the scale factor for the diffraction MTF is 1, leading to the conclusion that the diffraction MTF at a given depth of field is independent of sensor size.
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| In both the 'same photometric exposure' and 'same lens' conditions, the F-number is not changed, and thus the spatial cutoff and resultant MTF on the sensor is unchanged, leaving the MTF in the viewed image to be scaled as the magnification, or inversely as the crop factor.
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| ==Sensor format and lens size==
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| It might be expected that lenses appropriate for a range of sensor sizes could be produced by simply scaling the same designs in proportion to the crop factor.<ref>{{cite journal|last=Ozaktas|first=Haldun M|coauthors=Urey, Hakan and Lohmann, Adolf W.|title=Scaling of diffractive and refractive lenses for optical computing and interconnections|journal=Applied Optics|year=1994|volume=33|issue=17|pages=3782–3789|doi=10.1364/AO.33.003782}}</ref> Such an exercise would in theory produce a lens with the same F-number and angle of view, with a size proportional to the sensor crop factor. In practice, simple scaling of lens designs is not always achievable, due to factors such as the non-scalability of manufacturing tolerance, structural integrity of glass lenses of different sizes and available manufacturing techniques and costs. Moreover, to maintain the same absolute amount of information in an image (which can be measured as the space bandwidth product<ref>{{cite book|last=Goodman|first=Joseph W|title=Introduction to Fourier optics, 3rd edition|year=2005|publisher=Roberts and Company|location=Greenwood Village, CO|isbn=0-9747077-2-4|pages=26}}</ref>) the lens for a smaller sensor requires a greater resolving power. The development of the 'Tessar' lens is discussed by Nasse,<ref>{{cite web|last=Nasse|first=H. H.|title=From the Series of Articles on Lens Names: Tessar|url=http://www.zeiss.com/C12578620052CA69/0/58D501E36518AFC9C12578D2004104E1/$file/cln_39_en_tessar.pdf|publisher=Carl Zeiss AG.|accessdate=19 December 2011}}</ref> and shows its transformation from an f/6.3 lens for plate cameras using the original three-group configuration through to an f/2.8 5.2 mm four-element optic with eight extremely aspheric surfaces, economically manufacturable because of its small size. Its performance is 'better than the best 35 mm lenses – but only for a very small image'.
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| 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.
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| Small body means small lens and means small sensor, so to keep [[smartphone]]s slim and light, the smartphone manufacturers use tiny sensor usually less than 1/2.3" which usually use in most [[Bridge camera]]s and until now only [[Nokia 808 PureView]] uses 1/1.2" sensor which sensor size almost three times of 1/2.3" sensor size. To use bigger sensor has advantage of better image quality, but with sensor technology improves, small sensor initial to catch larger sensor, although the bigger sensor always on the lead, but not all of the consumers need superb photo quality or bigger sensor as we can see that smartphone has toppled low and middle end compact camera sales and uses for taking images.<ref>{{cite web |url=http://www.gizmag.com/camera-sensor-size-guide/26684/ |title=Camera sensor size: Why does it matter and exactly how big are they? |author=Simon Crisp |accessdate=January 29, 2014}}</ref>
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| == Sensor size and shading effects ==
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| Semiconductor image sensors can suffer from shading effects at large apertures and at the periphery of the image field, due to the geometry of the light cone projected from the exit pupil of the lens to a point, or pixel, on the sensor surface. The effects are discussed in detail by Catrysse and Wandell
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| .<ref name=Catrysse>{{cite journal|last=Catrysse|first=Peter B.|coauthors=Wandell, Brian A.|title=Roadmap for CMOS image sensors: Moore meets Planck and Sommerfeld|journal=Proceedings of the International Society for Optical Engineering|volume=5678|issue=1|doi=10.1117/12.592483| year = 2005 | url= http://www.imageval.com/public/Papers/EI%205678-01%20Peter%20Catrysse.pdf|accessdate=29 January 2012}}</ref>
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| In the context of this discussion the most important result from the above is that to ensure a full transfer of light energy between two coupled optical systems such as the lens' exit pupil to a pixel's photoreceptor the [[Etendue|geometrical extent]] (also known as etendue or light throughput) of the objective lens / pixel system must be smaller than or equal to the geometrical extent of the microlens / photoreceptor system. The geometrical extent of the objective lens / pixel system is given by
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| :<math> G_\mathrm{objective} \simeq \frac{w_\mathrm{pixel}}{2{(f/\#)}_\mathrm{objective}} </math>,
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| where {{math|<var>w<sub>pixel</sub></var>}} is the width of the pixel and {{math|<var>(f/#)<sub>objective</sub></var>}} is the f-number of the objective lens. The geometrical extent of the microlens / photoreceptor system is given by
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| :<math> G_\mathrm{pixel} \simeq \frac{w_\mathrm{photoreceptor}}{2{(f/\#)}_\mathrm{microlens}} </math>,
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| where {{math|<var>w<sub>photoreceptor</sub></var>}} is the width of the photoreceptor and {{math|<var>(f/#)<sub>microlens</sub></var>}} is the f-number of the microlens.
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| So to avoid shading,
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| :<math> G_\mathrm{pixel} \ge G_\mathrm{objective}</math>, therefore <math> \frac{w_\mathrm{photoreceptor}}{{(f/\#)}_\mathrm{microlens}} \ge \frac{w_\mathrm{pixel}}{{(f/\#)}_\mathrm{objective}}</math>
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| If {{math|<var>w<sub>photoreceptor</sub></var> / <var>w<sub>pixel</sub></var> {{=}} <var>ff</var>}}, the linear fill factor of the lens, then the condition becomes
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| :<math> {(f/\#)}_\mathrm{microlens} \le {(f/\#)}_\mathrm{objective} \times \mathit{ff}</math>
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| Thus if shading is to be avoided the f-number of the microlens must be smaller than the f-number of the taking lens by at least a factor equal to the linear fill factor of the pixel. The f-number of the microlens is determined ultimately by the width of the pixel and its height above the silicon, which determines its focal length. In turn, this is determined by the height of the metallisation layers, also known as the 'stack height'. For a given stack height, the f-number of the microlenses will increase as pixel size reduces, and thus the objective lens f-number at which shading occurs will tend to increase. This effect has been observed in practice, as recorded in the DxOmark article 'F-stop blues'<ref>{{cite web|last=DxOmark|title=F-stop blues|url=http://www.dxomark.com/index.php/Publications/DxOMark-Insights/F-stop-blues|work=DxOMark Insights|accessdate=29 January 2012}}</ref>
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| In order to maintain pixel counts smaller sensors will tend to have smaller pixels, while at the same time smaller objective lens f-numbers are required to maximise the amount of light projected on the sensor. To combat the effect discussed above, smaller format pixels include engineering design features to allow the reduction in f-number of their microlenses. These may include simplified pixel designs which require less metallisation, 'light pipes' built within the pixel to bring its apparent surface closer to the microlens and '[[Back-illuminated sensor|back side illumination]]' in which the wafer is thinned to expose the rear of the photodetectors and the microlens layer is placed directly on that surface, rather than the front side with its wiring layers. The relative effectiveness of these stratagems is discussed by [[Aptina]] in some detail.<ref>{{cite web|last=Aptina Imaging Corporation|title=An Objective Look at FSI and BSI|url=http://www.aptina.com/news/FSI-BSI-WhitePaper.pdf|work=Aptina Technology White Paper|accessdate=29 January 2012}}</ref>
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| ==Common image sensor formats==
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| [[File:SensorSizes.svg|thumb|300px|right|Sizes of the sensors used in most current digital cameras relative to a standard 35mm frame.]]
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| === Medium-format digital sensors ===
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| The most common sensor size for medium-format digital cameras is approximately {{convert|48|x|36|mm|abbr=on}}{{Citation needed|date=June 2010}}, due to the widespread use of [[Kodak]]'s 22-[[megapixel]] KAF-22000 and 39-megapixel KAF-39000<ref>{{cite pressrelease
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| | publisher = Kodak
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| | title = Kodak Announces Highest Resolution Image Sensors for Professional Photography
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| | date = 2005-10-20
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| | url = http://www.dpreview.net/news/article_print.asp?date=0510&article=05102101kodak_3936mpccd
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| }}{{dead link|date=March 2013}}</ref>
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| CCDs in that format. [[Phase One (company)|Phase one]] offers the P65+ digital back with [[Dalsa]]'s {{convert|53.9|x|40.4|mm|abbr=on}} sensor containing 60.5 megapixels<ref>{{cite web
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| | publisher = PHASE ONE
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| | title = The Phase One P+ Product Range
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| | accessdate = 2010-06-07
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| | url = http://www.phaseone.com/en/Digital-Backs/P65/~/media/Phase%20One/Products/Documents/Phase-One-digital-back-overview.ashx
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| }}</ref>
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| and [[Leica Camera|Leica]] offers an "S-System" DSLR with a {{convert|45|x|30|mm|abbr=on}} sensor containing 37-megapixels.<ref>{{cite pressrelease
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| | url = http://www.dpreview.com/news/0809/08092301_leica_s2.asp
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| | title = Leica S2 with 56% larger sensor than full frame
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| | publisher = Leica
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| | date = 2008-09-23
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| | accessdate = 2010-06-07
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| }}</ref> In 2010, [[Pentax]] released the 40MP 645D medium format DSLR with a {{convert|44|x|33|mm|abbr=on}} sensor.<ref>{{cite pressrelease
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| | url = http://www.dpreview.com/news/1003/10031002pentax645d.asp
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| | title = Pentax unveils 40MP 645D medium format DSLR
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| | publisher = Pentax
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| | date = 2010-03-10
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| | accessdate = 2010-12-21
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| }}</ref>
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| === Sensors equipping most DSLRs and mirrorless interchangeable-lens cameras ===
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| Some professional DSLRs use full-frame sensors, equal to the size of a frame of 35 mm film.
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| Most consumer-level DSLRs and [[mirrorless interchangeable-lens camera|MILCs/EVILs]] use relatively large sensors, either around 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 [[Olympus (company)|Olympus]] and [[Panasonic Corporation|Panasonic]]).
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| On September 2011, Nikon announced their new format CX, whose size is 1" (2.7 crop factor).<ref>[http://www.dpreview.com/news/1109/11092119nikonJ1.asp#press Nikon unveils J1 small sensor mirrorless camera as part of Nikon 1 system] at dpreview.com</ref> It has been adopted for the Nikon 1 camera system (Nikon J1 and V1 models), and subsequently, Sony released the pocket size Cybershot DSC RX-100 digital camera, in 2012, which also uses a 1" sensor.
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| {{As of|2013|11}} there is only one MILC model equipped with a very small sensor, typical of compact cameras: it is the [[Pentax_Q#Pentax_Q7|Pentax Q7]], equipped with a 1/1.7" sensor (4.55 crop factor). See [[#Sensors equipping compact digital cameras and camera-phones|Sensors equipping Compact digital cameras and camera-phones]] section below.
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| Many different terms are used in marketing to describe DSLR/MILC sensor formats, including the following:
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| * [[Full-frame digital SLR]] format, with sensor dimensions nearly equal to those of [[135 film|35 mm]] film (36 × 24 mm)
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| * [[Canon (company)|Canon]]'s APS-H format for high-speed pro-level DSLRs (crop factor 1.3)
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| * [[Leica Camera|Leica]]'s [[Leica M8|M8 and M8.2]] sensor (crop factor 1.33).
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| * [[APS-C]] refers to a range of similarly-sized formats, including
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| ** [[Nikon]], [[Pentax]], [[Samsung]], [[Konica Minolta]]/[[Sony]], [[Fujifilm]], [[Epson R-D1|Epson]], [[Sigma]] (crop factor 1.5)
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| ** [[Canon (company)|Canon]] (crop factor 1.6)
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| * [[Foveon X3]] format used in [[Sigma Corporation|Sigma]] SD-series DSLRs and DP-series mirrorless (crop factor 1.7) (latest models include [[Sigma SD1|SD1]], [[Sigma DP2 Merrill|DP2 Merrill]] use crop factor 1.5 foveon sensor)
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| * [[Four Thirds System]] and [[Micro Four Thirds System]] format (crop factor 2.0)
| |
| * [[Nikon CX format]] used in [[Nikon 1 series]] (crop factor 2.7)
| |
| | |
| When [[full-frame digital SLR|full-frame]] sensors were first introduced, production costs could exceed twenty times the cost of an APS-C sensor. Only twenty full-frame sensors can be produced on an {{convert|8|in|cm}} silicon wafer that would fit 100 or more APS-C sensors, and there is a significant reduction in [[Semiconductor device fabrication|yield]] due to the large area for contaminants per component. Additionally, the full frame sensor originally required three separate exposures during the [[photolithography]] stage, which requires separate masks and quality control steps. The APS-H size was selected since it was then the largest that could be imaged with a single mask to help control production costs and manage yields.<ref name=canon-wp>{{cite pressrelease
| |
| | url = http://www.robgalbraith.com/public_files/Canon_Full-Frame_CMOS_White_Paper.pdf
| |
| | title = Canon's Full Frame CMOS Sensors
| |
| | date = 2006
| |
| | accessdate = 2013-05-02
| |
| }}</ref> Newer photolithography equipment now allows single-pass exposures for full-frame sensors, although other size-related production constraints remain much the same.
| |
| | |
| Due to the ever-changing constraints of [[semiconductor fabrication]] and processing, and because camera manufacturers often source sensors from third-party [[semiconductor foundry|foundries]], it is common for sensor dimensions to vary slightly within the same nominal format. For example, the [[Nikon]] [[Nikon D3|D3]] and [[Nikon D700|D700]] cameras' nominally full-frame sensors actually measure 36 × 23.9 mm, slightly smaller than a 36 × 24 mm frame of 35 mm film. As another example, the [[Pentax]] [[Pentax K200D|K200D]]'s sensor (made by [[Sony]]) measures 23.5 × 15.7 mm, while the contemporaneous [[Pentax K20D|K20D]]'s sensor (made by [[Samsung Techwin|Samsung]]) measures 23.4 × 15.6 mm.
| |
| | |
| Most DSLR image sensor formats approximate the 3:2 [[aspect ratio]] of 35 mm film. Again, the [[Four Thirds System]] is a notable exception, with an aspect ratio of 4:3 as seen in most compact digital cameras (see below).
| |
| | |
| === Sensors equipping compact digital cameras, mega-zoom (bridge) cameras and camera-phones ===
| |
| | |
| Most image sensors equipping compact cameras have an [[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 Powershot SX230 IS, Fuji Finepix Z90 and Nikon Coolpix S9100. Some older [[digital camera]]s (mostly from 2005–2010) used a tiny 1/2.5" sensor: these include Panasonic Lumix DMC-FS62, Canon Powershot SX120 IS, Sony CyberShot DSC-S700, and Casio Exilim EX-Z80.
| |
| | |
| High-end compact cameras using sensors of nearly twice the area than sensors equipping common compacts include Canon PowerShot G12 (1/1.7") and Powershot S90/[[Canon PowerShot S95|S95]] (1/1.7"), Ricoh GR Digital IV (1/1.7"), Nikon Coolpix P7100 (1/1.7"), Samsung EX1 (1/1.7"), Panasonic DMC-LX5 (1/1.63") and Olympus XZ-1(1/1.63"). Fujifilm FinePix X-10 has a 2/3" sensor, the largest sensor on camera small enough to be labelled as compact (despite weighing 353 grams) until June 2012. That is until Sony announced DSC-RX-100, a real compact (weight: 213 grams) equipped with a 1" sensor (i.e. one only used on MILCs until then). Actually, Canon labels "compact camera" its PowerShot G1 X, equipped with a huge 1.5" sensor (i.e. a sensor larger than the 4/3" sensors equipping some compact DSLR). Nonetheless, weighing well over half a kilo (534 grams) G1 X is arguably a [[bridge camera]] rather than a compact.{{citation needed|date=June 2013}}
| |
| [[File:Digital camera sensor 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.]]
| |
| {{As of|2012}} most [[bridge camera]]s, including the Sony CyberShot DSC-HX100V and the Canon PowerShot SX40 HS, use a small 1/2.3" sensor (i.e. same size as those used in common compact cameras). The high-end bridge camera Fuji XS-1, though, is equipped with a much larger sensor (2/3" – twice the area of a 1/2.3" sensor: see table further on).
| |
| | |
| The sensors of [[camera phone]]s are typically much smaller than those of typical compact cameras, allowing greater miniaturization of the electrical and optical components. Sensor sizes of around 1/6" are common in camera phones, [[webcam]]s and [[digital camcorder]]s. The [[Nokia N8]]'s 1/1.83" sensor was the largest in a phone in late 2011. The [[Nokia 808]] surpasses compact cameras with its 41 million pixels, 1/1.2" sensor.<ref>http://europe.nokia.com/PRODUCT_METADATA_0/Products/Phones/8000-series/808/Nokia808PureView_Whitepaper.pdf Nokia PureView imaging technology whitepaper</ref>
| |
| | |
| === Table of sensor formats and sizes ===
| |
| | |
| Sensor formats of digital cameras are mostly expressed in the non-standardized "inch" system as approximately 1.5 times the length of the diagonal of the sensor. This goes back to the way image sizes of video cameras used until the late 1980s were expressed, referring to the outside diameter of the glass envelope of the [[video camera tube]]. [[David Pogue]] of ''The New York Times'' states that "the actual sensor size is much smaller than what the camera companies publish – about one-third smaller." For example, a camera advertising a 1/2.7" sensor does not have a sensor with a diagonal of 0.37"; instead, the diagonal is closer to 0.26".<ref>{{cite news| url=http://www.nytimes.com/2010/12/23/technology/personaltech/23pogue.html?ref=technology | work=The New York Times | first=David | last=Pogue | title=Small Cameras With Big Sensors, and How to Compare Them | date=2010-12-22}}</ref><ref name="dpreview-sensor-sizes" /> Instead of "formats", these sensor sizes are often called ''types'', as in "1/2-inch-type CCD."
| |
| | |
| Due to inch-based sensor formats being not standardized, their exact dimensions may vary, but those listed are typical.<ref name="dpreview-sensor-sizes">{{cite web | url=http://www.dpreview.com/learn/?/Glossary/Camera_System/sensor_sizes_01.htm | title=Sensor Sizes: Camera System: Glossary: Learn |
| |
| first=Vincent | last=Bockaert | publisher=[[Digital Photography Review]] | accessdate=2012-04-09}}</ref> <!-- Every word or number of the following two sentences is VERY carefully selected. PLEASE see talk page, think twice about the physics of optics before you change anything. Thank you very much. -->The listed sensor areas span more than a factor of 1000 and are [[Proportionality (mathematics)|proportional]] to the maximum possible collection of light and [[image resolution]] (same [[lens speed]], i.e., minimum [[F-number]]), but in practice are not directly proportional to [[image noise]] or resolution due to other limitations. See comparisons.<ref name="dxoa">[http://www.dxomark.com/index.php/Cameras/Camera-Sensor-Ratings Camera Sensor Ratings] DxOMark</ref><ref name="imac">[http://www.imaging-resource.com/IMCOMP/COMPS01.HTM Imaging-resource: Sample images Comparometer] Imaging-resource</ref><!-- PLEASE see above. Thank you. --> Film format sizes are included for comparison.
| |
| <!-- To recompute these with Scientific Python:
| |
| | |
| w = array of widths
| |
| l = array of lengths
| |
| | |
| d = sqrt(w**2+l**2)
| |
| cf = sqrt(36**2+24**2) / d
| |
| area = w*l
| |
| | |
| print ' || '.join(str(x) for x in around(d, 1)) # print diagonals in wikitable format
| |
| print ' || '.join(str(x) for x in around(cf, 2)) # print crop factors in wikitable format
| |
| print ' || '.join(str(x) for x in around(area, 2)) # print areas in wikitable format
| |
| -->
| |
| | |
| {| style="width: 100%; text-align: center;" border="1" cellspacing="0" class="wikitable sortable"
| |
| ! Type !! Diagonal (mm) !! Width (mm) !! Height (mm) !! Area (mm<sup>2</sup>) !! [[F-number#Stops, f-stop conventions, and exposure|Stops]] (area) !! [[Crop factor]]<ref>Defined here as the ratio of the diagonal of a full 35 frame to that of the sensor format, that is CF=diag<sub>35mm</sub> / diag<sub>sensor</sub>.</ref>
| |
| |-
| |
| |1/10"
| |
| |1.60||1.28||0.96||1.23||-9.51||27.04
| |
| |-
| |
| |1/8"
| |
| |2.00||1.60||1.20||1.92||-8.81||21.65
| |
| |-
| |
| |1/6"
| |
| |3.00||2.40||1.80||4.32||-7.64||14.14
| |
| |-
| |
| |1/4"
| |
| |4.00||3.20||2.40||7.68||-6.81||10.81
| |
| |-
| |
| |1/3.6" ([[Nokia Lumia 720]])<ref>{{Citation
| |
| | coauthors = GSMArena.com
| |
| | title = Nokia Lumia 720 – Full phone specifications
| |
| | date = February 25, 2013
| |
| | accessdate=2013-09-21
| |
| | url = http://www.gsmarena.com/nokia_lumia_720-5321.php}}</ref>
| |
| |5.00||4.00||3.00||12.0||-6.16||8.65
| |
| |-
| |
| |1/3.2" ([[iPhone 5]])<ref>{{Citation
| |
| | coauthors = Gizmag
| |
| | title = Camera sensor size: Why does it matter and exactly how big are they?
| |
| | date = March 21, 2013
| |
| | accessdate=2013-06-19
| |
| | url = http://www.gizmag.com/camera-sensor-size-guide/26684/}}</ref>
| |
| |5.68||4.54||3.42||15.50||-5.80||7.61
| |
| |-
| |
| |''Standard [[8 mm film#Standard 8|8mm film]] frame''
| |
| |5.94||4.8||3.5||16.8||-5.73||7.28
| |
| |-
| |
| |1/3" ([[iPhone 5S]])
| |
| |6.00||4.80||3.60||17.30||-5.64||7.21
| |
| |-
| |
| |1/2.7"
| |
| |6.72||5.37||4.04||21.70||-5.31||6.44
| |
| |-
| |
| |[[Super 8 film|''Super 8mm film'']]'' frame''
| |
| |7.04||5.79||4.01||23.22||-5.24||6.15
| |
| |-
| |
| |1/2.5" (Sony T5)
| |
| |7.18||5.76||4.29||24.70||-5.12||6.02
| |
| |-
| |
| |1/2.3" ([[Pentax Q]]) ( Sony DSC-W330)
| |
| |7.66||6.17||4.55||28.50||-4.92 ||5.64
| |
| |-
| |
| |1/2" ([[Fujifilm HS30EXR]])
| |
| |8.00||6.40||4.80||30.70||-4.81||5.41
| |
| |-
| |
| |1/1.8" ([[Nokia N8]])
| |
| |8.93||7.18||5.32||38.20||-4.50||4.84
| |
| |-
| |
| |1/1.7" ([[Pentax Q7]])
| |
| |9.50||7.60||5.70||43.30||-4.32||4.55
| |
| |-
| |
| |1/1.6"
| |
| |10.07||8.08||6.01||48.56||-4.15||4.30
| |
| |-
| |
| |2/3" ([[Lumia 1020|Nokia Lumia 1020]], [http://www.imaging-resource.com/PRODS/XS1/XS1A.HTM Fujifilm X-S1], X20, XF1)
| |
| |11.00||8.80||6.60||58.10||-3.89||3.93
| |
| |-
| |
| |''Standard [[16 mm film#Standard 16 mm|16mm film]] frame''
| |
| |12.7||10.26||7.49||76.85||-3.49||3.41
| |
| |-
| |
| |1/1.2" ([[Nokia 808 PureView]])
| |
| |13.33||10.67||8.00||85.33||-3.34||3.24
| |
| |-
| |
| |Blackmagic Pocket Cinema Camera
| |
| |14.32||12.48||7.02||87.6||-3.30||3.02
| |
| |-
| |
| |''Super 16mm film frame''
| |
| |14.54||12.52||7.41||92.80||-3.22||2.97
| |
| |-
| |
| |1" [[Nikon CX format|Nikon CX]], [[Sony Cyber-shot DSC-RX100|Sony RX100]] and [[Sony Cyber-shot DSC-RX10|Sony RX10]]
| |
| |15.86||13.20||8.80||116||-2.90||2.72
| |
| |-
| |
| |1"
| |
| |16.00||12.80||9.60||123||-2.81||2.70
| |
| |-
| |
| |Blackmagic Cinema Camera EF
| |
| |18.13||15.81||8.88||140||-2.62||2.38
| |
| |-
| |
| |[[Four Thirds system|Four Thirds]], [[Micro Four Thirds system|Micro Four Thirds]] ("4/3", "m4/3")
| |
| |21.60||17.30||13||225||-1.94||2.00
| |
| |-
| |
| |1.5"
| |
| |23.36||18.70||14.00||262||-1.72||1.85
| |
| |-
| |
| |Blackmagic Production Camera 4K
| |
| |24.23||21.12||11.88||251||-1.78||1.79
| |
| |-
| |
| |original [[Foveon X3 sensor|Sigma Foveon X3]]
| |
| |24.90||20.70||13.80||286||-1.60||1.74
| |
| |-
| |
| |Canon [[EF-S]], [[APS-C]]
| |
| |26.70||22.20||14.80||329||-1.39||1.62
| |
| |-
| |
| |''Standard [[35 mm film#Academy format|35mm film]] frame''
| |
| |27.20||22.0||16.0||352||-1.34||1.59
| |
| |-
| |
| |[[APS-C]] ([[Nikon DX format|Nikon DX]], [[Pentax K mount|Pentax K]], [[Samsung NX-mount|Samsung NX]], [[Sony Alpha|Sony α DT]])
| |
| |28.2–28.4||23.6–23.7||15.60||368–370||-1.23||1.52–1.54
| |
| |-
| |
| |''[[Super 35]]mm film frame''
| |
| |31.11||24.89||18.66||464||-0.95||1.39
| |
| |-
| |
| |Canon [[APS-H]]
| |
| |33.50||27.90||18.60||519||-0.73||1.29
| |
| |-
| |
| |[[Full-frame digital SLR|35mm full-frame]], ([[Nikon|Nikon FX]], [[Sony Alpha|Sony α]], [[Canon (company)|Canon EF]])
| |
| |43.2–43.3||36||23.9–24.3||860–864||0||1.0
| |
| |-
| |
| |[[Leica_Camera#S (medium format dSLR) series|Leica S]]
| |
| |54||45||30||1350||+0.64||0.80
| |
| |-
| |
| |Pentax [[Pentax 645D|645D]]
| |
| |55||44||33||1452||+0.75||0.78
| |
| |-
| |
| |[[70_mm_film#Technical_specifications|''Standard 65mm'']]'' film frame''
| |
| |57.30||52.48||23.01||1208||+0.81||0.76
| |
| |-
| |
| | Kodak KAF 39000 CCD<ref>{{Citation
| |
| | coauthors = KODAK
| |
| | title = KODAK KAF-39000 IMAGE SENSOR, DEVICE PERFORMANCE SPECIFICATION
| |
| | date = April 21, 2010
| |
| | url = http://www.kodak.com/global/plugins/acrobat/en/business/ISS/datasheet/fullframe/KAF-39000LongSpec.pdf}}{{dead link|date=March 2013}}</ref>
| |
| | 61.30 || 49 || 36.80 || 1803 || +1.06 || 0.71
| |
| |-
| |
| | Leaf AFi 10
| |
| | 66.57 || 56 || 36 || 2016 || +1.22 || 0.65
| |
| |-
| |
| | [[Medium format (film)|Medium-format]] ([[Hasselblad]] H5D-60)<ref>{{Citation
| |
| | coauthors = B&H PHOTO VIDEO
| |
| | title = Hasselblad H5D-60 medium-format DSLR camera
| |
| | date =
| |
| | accessdate=2013-06-19
| |
| | url = http://www.bhphotovideo.com/c/product/893195-REG/Hasselblad_H5D_60_DSLR_Camera_With.html}}</ref>
| |
| | 67.08 || 53.7 || 40.2 || 2159 || +1.26 || 0.65
| |
| |-
| |
| | Phase One [[Phase One (company)|P 65+]], IQ160, IQ180
| |
| | 67.40 || 53.90 || 40.40 || 2178 || +1.33 || 0.64
| |
| |-
| |
| |[[70_mm_film#IMAX_.2815.2F70.29|''IMAX'']]'' film frame''
| |
| |87.91||70.41||52.63||3706||+2.05||0.49
| |
| |-
| |
| |}
| |
| | |
| ==See also==
| |
| | |
| * [[Full-frame digital SLR]]
| |
| * [[Digital photography#Sensor size and angle of view|Sensor size and angle of view]]
| |
| * [[35 mm equivalent focal length]]
| |
| * [[Film format]]
| |
| * [[Digital versus film photography]]
| |
| * [[List of large sensor interchangeable-lens video cameras]]
| |
| | |
| ==Notes and references==
| |
| | |
| {{Reflist}}
| |
| | |
| ==External links==
| |
| * Eric Fossum: [http://www.youtube.com/watch?v=JkBh71zZKrM Photons to Bits and Beyond: The Science & Technology of Digital], Oct. 13, 2011 (YouTube Video of lecture)
| |
| * Joseph James: [http://www.josephjamesphotography.com/equivalence/ Equivalence] at Joseph James Photography
| |
| * Simon Tindemans: [http://www.21stcenturyshoebox.com/essays/formatindependence/ Alternative photographic parameters: a format-independent approach] at 21stcenturyshoebox
| |
| * [http://web.archive.org/web/20110605233923/http://www.dpreview.com/articles/compactcamerahighiso/ Compact Camera High ISO modes: Separating the facts from the hype] at dpreview.com, May 2007
| |
| * [http://6mpixel.org/en/ The best compromise for a compact camera is a sensor with 6 million pixels or better a sensor with a pixel size of >3µm] at 6mpixel.org
| |
| | |
| {{DEFAULTSORT:Image Sensor Format}}
| |
| [[Category:Digital photography]]
| |
| [[Category:Image sensors]]
| |